Recycle • Reuse • Repurpose
Places Kraton’s HiMA Stay Safe: Milling Extras
AR at NCAT, Africa Build the Safety Edge Add RAS with Assurance When to Replace Blow Bars June/July 2012
Departments Letter from the Editor 5 Don’t Waste My Taxes on High-Speed Fail Around the Globe 6 Safety Spotlight 8 Top 5 Tips to Choose High Quality Asphalt Boots by Inga Bemman
Mix It Up 10 GTR Meets SBS on the Track Ground tire rubber-modifier performs equivalently to s tyrene-butadiene-styrene-modifier on the NCAT test track by Maria Carolina Rodezno Project Management 14 Mill Professionally for Better Project Success by John Ball
22 Add RAS with Accuracy, Assurance Overcome material challenges with quality control at producer level by Sandy Lender
30 Call Congress Now Here’s how to make your voice heard in the highway funding battle by Sandy Lender and Jenny Williamson 36 New Binder Allows Thinner Pavements That Resist Cracking, Rutting by Paul Fournier
Equipment Maintenance 20 Maintain the Crusher for Optimum Recycling by Wade Lippert Equipment Gallery 64 Diagnose Problems Remotely with Roadtec Telematics
38 Oklahoma Anticipates I-40 Performance Gain with HiMA by Tom Kuennen 44 Haskell Lemon Gives ODOT Success Story by Sandy Lender
Here’s How It Works 70 Roadtec’s SP-200 Spray Paver™ 72 Maxam’s Perma Stor™ Silo System
46 South Africa Recycles with RMB by Richard Champion
Resource Directory 73
50 Here’s How to Build a Safety Edge by Sandy Lender
Last Cut 74 It’s As Simple As That by Sandy Lender
60 International Stabilization by John Hood
62 Russian Show’s Strength is Face to Face by Sandy Lender 68 Top 10 Products for 2012 Recycle • Reuse • Repurpose
Places Kraton’s HiMA Stay Safe: Milling Extras
AR at NCAT, Africa Build the Safety Edge Add RAS with Assurance When to Replace Blow Bars JUNE/JULY 2012
On The Cover…The team from Haskell Lemon won the bid to produce and place a new highly polymer-modified asphalt binder on Oklahoma’s I-40 in April. See related article on page 38. Photo courtesy of Kraton Polymers. www.theasphaltpro.com | ASPHALT PRO 3
editor's note June/July 2012 • Vol. 5 No. 8
Don’t Waste My Taxes on High-Speed Fail
2001 Corporate Place Columbia, MO 65202 573-499-1830 • 573-499-1831 www.theasphaltpro.com publisher
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Sandy Lender firstname.lastname@example.org (239) 272-8613 Art Director
Kristin Branscom operations/circulation manager
Cindy Sheridan business manager
Renea Sapp AsphaltPro is published nine times per year: January, February, March, April/May, June/July, August/September, October, November and December by The Business Times Company, 2001 Corporate Place, Columbia, MO 65202 Writers expressing views in AsphaltPro Magazine or on the AsphaltPro website are professionals with sound, professional advice. Views expressed herein are not necessarily the same as the views of AsphaltPro or Business Times Company staff, thus producers/contractors are still encouraged to use best practices when implementing new advice. Subscription Policy: Individual subscriptions are available without charge in the United Sates, Canada and Mexico to qualified individuals. One year subscription to non-qualifying Individuals: United States $90, Canada and Mexico $125.00 and $175.00 all other countries (payable in U.S. funds, drawn on U.S. bank). Single copies available $17 each.
How many people do you know who live fulltime near a California beach, but work in, say, Ohio? I’m not putting Ohio down; my grandmother used to live there and her property was gorgeous with a nice pond for fishing. We have 50 states in the Unites States of America and U.S. News reports about 312.8 million people live among them. Is the high- Photo courtesy of Tom Kuennen, speed rail (HSR) movement suggesting it can Expressways Online accommodate enough of those people with trains and tracks to make its high cost worth the investment? There’s where HSR proponents usually say something to the effect of “most trains will stop in between Point A and Point Z, making the trains accessible for more users.” There’s where HSR fails to be high speed and becomes just another train system that happened to cost more than I think it should have, happened to take up more protected lands than I think it should have, and diverted time, funds and energy from the economy-promoting portion of transportation infrastructure— our highway system. Let’s take a recent scenario in Florida as an example. HSR proponents wanted to build a system between Orlando, a popular tourist destination, and Tampa/ St. Pete, which the U.S. Census Bureau reported had a combined population of 580,478 in 2010. For the record, both cities have international airports. They also have major highways that lead north and south for hurricane evacuation and seasonal-resident travel, and east and west for tourist travel and whatnot. Orlando to Tampa is 84 miles; to St. Pete it’s 104. Pretend for a moment you’re back in school. If a train leaving a station in Orlando were taking 6,849.3 tourists and businessmen (based on a mythical projection of 2.5 million users in the first year by the firm of Steer, Davis & Gleave) to a station in Tampa/St. Pete, how many of the passengers would have their necks snapped if the train reached its maximum velocity one-quarter of the way to its destination? Too graphic? Apparently, it’s too graphic for the HSR folks, too. They admitted pretty early on that a train traveling from one side of Florida to the other wouldn’t actually reach high speeds. That’s where I start to wonder why it would be called “high speed.” As a tax-payer living about two hours south of Tampa/St. Pete, I’d like a station here in Lee County with a train that takes me and my pet birds to Georgia in an hour or less when a hurricane’s bearing down on the peninsula. But I think the train would have to stop in Sarasota to pick up more people. And again in Tampa. And again in Gainesville. Once again, the rail would fail to be “high speed.” Consider the effect of power failures and natural events, too. You know a strong wind knocked a freight train off its rails in Illinois May 7. Thankfully there were no passengers on it and the news reported no injuries; only a huge mess that would take the line out of commission for days during clean-up. When hurricanes sweep through this area, the rain bands that precede them often knock out power. Would the HSR fail? How about in the case of an earthquake? Tornado? Or just a bad storm that knocks out the power during the evening commute? Sadly, the power grid should stay up in the event of a zombie outbreak, so HSR really fails us if monsters should get on board the trains and zip across whatever state(s) the system leads to. If HSR worked, it would merely facilitate a zombie apocalypse, but not get me out of the path of a hurricane? continued on page 9 www.theasphaltpro.com | ASPHALT PRO 5
around the globe
Industry News and Happenings from Around the World China
Visitors from China First Highway Consultants Co. Ltd. (FHCC) visited the National Asphalt Pavement Association (NAPA), Lanham, Md., in May. FHCC is the largest consulting highway design company in China and has designed at least a third of China’s 52,000-mile National Trunk Highway System. Similar to the United States, 95 percent of China’s pavements are asphalt. Source: NAPA Action News
Indian Oil Emulsion Bulk and Packed Bitumen prices increased in May after the country had imported 26,855 megatonnes of bitumen from UAE in the first quarter of the year. Source: Petrosil’s Bitumart
According to Petrosil’s Bitumart, Korea’s bitumen marketplace saw a downturn in February. The news source reported that Korea’s domestic sales of bitumen decreased by 42 percent that month compared to January while the country’s export of bitumen decreased by 15 percent that month as compared to January. Bitumart went on to report that Korean production then surged by 39 percent in March.
CEI Enterprises co-sponsored the 26th PSWNA Polish Asphalt Pavement Association Technical Seminar held at the BOSS Hotel in Warsaw this March 21 through 23. The topic of the three-day seminar was “Rubber Modified Bitumen Asphalt Emulsions, Technology-Application-Experience,” and included an update from the U.S. Rubber Pavements Association (RPA) and technical studies from leading researchers from Warsaw University of Technology, Wroclaw University of Technology and the Polish administration (GDDKiA).
Singapore bitumen imports firmed up by 7 percent in February compared to previous month imports, with most of its bitumen coming from Thailand. Source: Petrosil’s Bitumart.
• As this issue goes to press, select members of the House of Representatives are discussing the next highway transportation funding bill. See page 30 for more information and visit 6 June/july 2012
www.TheAsphaltPro.com for the online version of the article with live links to the websites of conferees discussing the bill. • For up-to-the-minute funding and legislative updates that impact the asphalt industry, follow http://twitter.com/AsphaltPro.
New research from the National Center for Asphalt Technology (NCAT) shows that warm-mix asphalt (WMA) may reduce plant fuel use more than experts previously realized due to reduced drum casing losses in addition to lower mix temperatures. NAPA Vice President for Environmental Affairs Howard Marks pointed out that plant burner fuel consumption was reduced by as much as 20 percent for a 50oF reduction in temperature when using WMA technologies. Lab tests tend to indicate some potential for moisture damage with WMA—compared to HMA—but NCAT’s actual field projects have found no evidence of this. “The field performance of WMA has been excellent, even in heavy traffic and tough climates,” NCAT Director Randy West said. “We need to take these lab tests with a grain of salt and realize that the lab conditions or criteria are not perfect and need to be adjusted based on the field truth.” In the meantime, industry can count on the environmental findings that WMA technologies result in almost no worker exposure to asphalt fumes and offer exceptional fuel savings from using warm mix. Source: NAPA Action News
E2 Safety Gear offers OSHA 10 Training June 9 and June 16 at $125 per person. Contact Mary Bowman at (602) 541-9623 to register.
Assemblyman Jared Huffman (D-Marin) introduced AB 1704 in the California Legislature to ban the sale and use of pavement sealers that contain coal tar in the state. Strangely enough, an Assembly committee found there was no evidence that sealants with coal tar are used in California. Source: May 7 California Asphalt Insider
The Asphalt Institute added Mike Kolos, most notably of United Refining Co., and Tom Reynolds, most notably of Standard Oil of Indiana and AMOCO, to its Roll of Honor at its spring meeting in Baltimore. Both men served as A.I. chairmen in the past. Source: Asphalt
Allmand Bros., Inc., Holdrege, Neb., is expanding its manufacturing facility to the tune of $3 million. This means the building will get 40,000 more square feet and the parking area for finished goods storage will get 17 more acres. President Matt Allmand says the addition of an enlarged fabrication area and a new higher-speed laser cutting machine and a new press brake will allow the company to increase production time. They should go from the current 16 to 17 weeks of lead time to about four weeks or so. Holdrege gets a boost, too, with the company planning to add more employees and bring some outside metal fabrication in-house.
Michael Deane, the vice president of sustainability at the international Turner Construction Co., New York, N.Y., received the 2012 C&D Recycler of the Year award. The Construction Materials Recycling Association (CMRA) President and CEO of CPRC Group, Scarborough, Maine, John Adelman, said “Deane has had a first-hand view of the challenges and advantages of recycling C&D materials. He has guided one of the largest general construction companies in a number of sustainable areas, but in C&D recycling he has realized the importance of ensuring the legitimate recycling of the materials generated at construction and demolition sites.”
Gov. Bill Haslam and the Tennessee Department of Transportation unveiled a three-year road improvement initiative in mid-April that involves 96 projects ranging from overpass construction to ramp lengthening near I-440 to a key interchange that will connect the northern part of Sumner County directly to I-65. Officials hope to improve safety and stimulate economic growth. Source: Tennessean.com
Gulf Oil has partnered with Petroleum Wholesale LP to rebrand 50 ExxonMobil gasoline service stations in the Houston area, beginning this spring. Gulf Oil is a fuel retailer and distributor without refining operations. Source: FuelFix.com
The Road Gang named ARTBA President Pete Ruane its 2012 recipient of the Road Gang’s P.D. McLean Memorial Award, which annually honors an individual “for a distinct contribution to the cause of better highway transportation in the public interest.” Source: ARTBA .
Top 5 Tips to Choose High Quality Asphalt Boots by Inga Bemman
arilyn Monroe said, “Give a girl the right shoes and she can conquer the world.” What about asphalt professionals? You’re not looking to conquer the world, but you want to be safer, more productive and more effective on the paving crew and at the plant and quarry sites. The right boots and shoes are critical for that. Here are some of the traits that make a pair of asphalt boots right for our industry and for your feet. 1. Non-toxic leather Some asphalt boots are manufactured with AZO and/or PCP dyes, which have been proven harmful to our health and toxic to the environment. Steer clear. Look for boots with a certificate from the leather manufacturer stating the boots are made with no toxic materials, dyes or components. As asphalt professionals, we’re always finding ways to protect the environment—don’t stop before you get to your toes. 2. Specialized leather lining For maximum comfort, the lining of the asphalt boot should be made from sweat-absorbent and/or breathable leather. A leather insole can add a completely new dimension of comfort and protection to the boot. Consider the heat of the screed or the mat you often come in contact with; not to mention the ambient temperatures in which you typically pave. The right lining offers improved foot health. 3. Option to accommodate orthopedic cushions If you need added support in your asphalt boots, some brands such as the Italian-made COFRA have a replaceable cushion that can fit special orthopedic soles or cushions. You may require this added feature if your doctor prescribed special insoles for medical or hygienic
8 June/july 2012
purposes, or if you feel you need that added level of protection and comfort. Even if you operate the wheel loader at the plant or the broom on the milling crew, this job demands you spend an inordinate amount of time on your feet. Put off exhaustion and foot pain— thus increasing personal safety— with footwear that offers correct support. 4. The boots should fit It sounds obvious, but you’d be surprised how often we neglect this issue. Comfort and fit are paramount. A shoe that doesn’t fit can cause safety issues, health problems and discomfort. Your outer sole must have sufficient clamping with the footfall; that means the boot shouldn’t flop when you walk and your foot shouldn’t rub against the inner surface of the boot. 5. Large footfall surface If the footfall surface of the shoe is too small or cramped, the shoes will hurt. Additionally, the shape of the boot must fit your foot in every way. Consider the footprint you leave on the mat as well. Small footfall surfaces leave cuts and marks where you step and turn. A larger footfall surface with a more rounded shape offers a gentler hit to the mat. It’s not quite a tamping shoe, but it’s less cursing from the roller operator. Follow this checklist when you buy your next pair of asphalt boots for the maximum in comfort and safety. You’ll find you have a pair of boots made not only for walking, standing and working for hours of intense labor in high-heat conditions, but also for your specific industry applications. Inga Bemman is the vice president of Sunar, Inc. You can reach her at (571) 239-0940 or email@example.com.
Make sure the shape of the boot fits your foot in every way.
continued from page 5
To be serious, many HSR proponents believe that getting more people to live in cities where trains pick them up and drop them off will save the earth. Less gas is wasted in congested traffic backups if we’re all on trains that move us from city to city, with the caveat, of course, that we don’t get on a bus or in a taxi at the destination city. We have to stop next to a bike lot and pedal our way to the final destination or stop next to an imaginary building (or commune?) where all business takes place. In a perfect world, we wouldn’t travel between cities at all, therefore eliminating the need for the electricity or other energy source to power the trains. We’d be next to the plot that feeds the sheep that provide the wool for the clothes we make ourselves, so there’d be no need for trucks to deliver products across useless roads. I bet we could grow vegetable plants out of the cracks in the joints in concrete pavements. That gray stuff becomes useful at last. Honestly, I don’t see myself giving up my Charger with its angry-looking grill so I can sit on a train that stops miles from my home. HSR has too many issues to resolve. I’m not thrilled with all of Florida Gov. Rick Scott’s policies, but I’ve got to applaud him for shooting down the HSR initiative in early 2011. LaHood’s temper tantrum that took the $2.4 billion in a federal gift for the project showed what kind of game the HSR proponents are playing with our infrastructure. We either build crap citizens don’t want or need, or they take oodles of dollars elsewhere. The folks in California are currently trying to cough up the moxy and the ever-growing need for more start-up money to use the gift LaHood rescinded from Florida. Strangely, I couldn’t find one current cost that was consistent across my sources, but the words “significantly more” than $2.4 billion kept cropping up. Bids from foreigners seem popular, too. I don’t think that allowing a consortium from China, France, Germany, Japan, Spain or South Korea to bid on the work holds up the HSR’s concept of job promotion here. To sum up, HSR initiatives are based on a social system that doesn’t exist and require monies that would be better used on highways, roads and bridges that support a social system that does exist. More representatives are figuring this out, but it’s a good idea to watch out for the mainstream media moguls who flash pie-in-the-sky projections based on future riding habits of people who don’t currently ride trains to places they don’t currently go. Keep the zombies where they originate and I’ll keep my freedom to drive when and where I wish. Stay Safe
www.theasphaltpro.com | ASPHALT PRO 9
mix it up
GTR Meets SBS on the Track Ground tire rubber-modifier performs equivalently to styrene-butadiene-styrene-modifier on the NCAT test track by Maria Carolina Rodezno
roducers and state highway agencies move forward with the implementation of more environmentally friendly products for use in asphalt mixes, while others look for more competitive products that can provide similar or better performance. In 2008, the asphalt paving industry experienced a shortage of styrene-butadiene-styrene (SBS) caused by a reduction in the production of butadiene as a result of increases in crude oil prices. This shortage underlined the need for alternatives for SBS, the most common polymer for modifying asphalt binders. In the past, ground tire rubber (GTR) modified asphalt binders were typically blended on-demand at the contractorâ€™s asphalt plant. This process makes the certification of the desired binder properties challenging. Some asphalt binder terminal facilities now have the capability to blend GTR more consistently to provide more assurance that the modified binder meets the spec requirements. In 2009, the Missouri Department of Transportation (MoDOT) sponsored the construction of two test sections at the National Center for Asphalt Technology (NCAT) Pavement Test Track to determine if GTR would be an adequate substitute for SBS in asphalt mixes. These two test sections were constructed on perpetual pavement foundations to ensure that distresses were indicative of the surface mixâ€™s performance and not that of the subgrade or base material. The first asphalt mix was a 100 gyration SBS-modified dense-graded Superpave mix with a 12.5-mm nominal maximum aggregate size (NMAS). The second mix used a similar aggregate gradation and compactive effort; however, instead of modifying the asphalt with SBS, the base PG76-22 asphalt binder was modified with 11 percent 30-40 mesh rubber to bump the high temperature grade. Both mixes were constructed 1.8 inches thick to a density of 93 percent of theoretical maximum density. Both modified asphalt binders graded to meet the requirements for PG76-22. A total of 10 million equivalent single-axle loads (ESALs) through two years of trafficking were applied to the sections. Performance of the test sections was monitored throughout the two-year period. An inertial profiler measured rut depths, smoothness in both wheel paths and pavement texture weekly while monthly crack maps were developed to monitor which mix was more susceptible to cracking. 10 June/july 2012
We sampled each binder and its corresponding mix for complete laboratory characterization in terms of performance grading, moisture susceptibility, stiffness, rutting, low-temperature cracking and surface cracking using standard laboratory procedures. The two binders used in the mixes were tested in the NCAT binder laboratory to determine the performance grade (PG) in accordance with AASHTO M 320-10. The results confirmed that both binders used in the construction of the two sections were PG76-22 binders. We performed moisture susceptibility testing in accordance with AASHTO T 283-07. AASHTO M323-07 recommends a tensile strength ratio (TSR) value of 0.8 and above for moisture resistant mixes. Both mixes exceeded that criterion, indicating resistance to moisture damage. Although the TSR of the GTR mix was slightly higher than the SBS mixture (0.90 and 0.86, respectively) the precision of TSR testing is such that these results are considered practically equivalent. One of the important properties of an asphalt mix is its dynamic modulus, which is a measure of its stiffness. Both mixes were evaluated in an Asphalt Mixture Performance Tester (AMPT) to determine the dynamic modulus under a number of temperatures and load frequencies. We prepared samples for this testing in accordance with AASHTO PP 60-09, and conducted testing in accordance with AASHTO TP 79-09. We analyzed the data for two specific purposes. First, we used the data to generate a mastercurve for each individual mix in accordance with AASHTO PP 61-09. The mastercurve uses the principle of time-temperature superposition to shift data at multiple temperatures and frequencies to a reference temperature so that the stiffness data can be viewed without temperature as a variable. This method of analysis allows for visual relative comparisons between multiple mixes. Figure 1 shows the unconfined mastercurves of the two mixes. The mix performance at the low-temperature, high-frequency (right side) portion of the mastercurve shows equivalent mix stiffness. At the intermediate temperatures (middle of the curves), there is some deviation between the stiffnesses of the mixes. More separation in the mastercurves is noticed at the high-temperature, low-frequency portion of the curve. However, a statistical analysis of the data indicated no statistical difference in the stiffness of the two mixes (See Figure 1). We evaluated the rutting susceptibility of the GTR and SBS mixes using the Asphalt Pavement Analyzer (APA)
mix it up Technicians can assess a mix’s resistance to top-down or surface cracking using the energy ratio (ER) analysis. To determine this mix property, specimens were tested for resilient modulus, creep compliance and tensile strength at 10°C. The analysis shows slight differences in the energy ratio of the two mixes: 4.96 for the GTR mix and 4.43 for the SBS mix. The SBS mix has a slightly lower energy ratio, which suggests that the GTR mix would perform slightly better in terms of surface cracking. Current recommendations suggest that a minimum ER of 1.95 is needed for pavements with up to 1,000,000 ESALs per year. While the test track trafficking exceeds this requirement, one can see that both mixes are more than twice the required ER. Hence, this testing shows that both mixes should have acceptable resistance to top-down cracking.
and the Flow Number Test (Fn). For the APA testing, we followed the AASHTO TP 63-09 protocol. The samples were tested at a temperature of 64°C and an acceptance criterion of 5.5 mm. Past research at the test track has shown that if a mix has an average APA rut depth less than 5.5 mm, it should be able to withstand at least 10 million ESALs of traffic without accumulating more than 12.5 mm of field rutting. The APA results for both mixtures was 1.4 mm. The flow number for the mixes was determined using the AMPT. A higher Fn indicates a more rut-resistant mix. We conducted the Fn tests at a temperature of 59.5°C and at a deviator stress of 87 psi without confinement. The average flow number for the SBS mix was 320 cycles, and for the GTR mix, 660 cycles. While the APA test results suggest the two mixes have overall equivalent resistance to permanent deformation, the Fn test suggests the GTR mix is more resistant to rutting. In either case, the results show that the GTR mix has at least equivalent resistance to rutting when compared to an SBS mix. The low-temperature cracking performance of asphalt mixes can be characterized using the critical cracking temperature. This is the temperature at which the estimated thermal stress exceeds a mix’s tested indirect tensile strength. A mix exhibiting a lower critical cracking temperature than those of the other mixes would have better resistance to thermal cracking. To estimate the thermal stress and measure the tensile strength at failure, we conducted the indirect tensile creep compliance at 0°C, -10°C and -20°C and tensile strength at -10°C for each mix, as specified in AASHTO T 322-07. We evaluated both the SBS and GTR mixes using a critical temperature analysis. The GTR mix performed either equivalent to or better than the SBS mix in terms of strength, time until failure and lower critical temperature. 12 June/july 2012
Real-World GTR Implementation
The field performance evaluation showed that after 10 million ESALs of trafficking, neither mix has shown signs of cracking. Both test sections have rut depths less than 5 mm. While this testing is not yet conclusive, it provides good evidence that PG-graded asphalts modified with GTR should perform as well as binders modified with SBS. Based on this test track study and other work, MoDOT changed its binder spec (Section 1015) to include an alternative to produce binder in accordance with AASHTO MP 19, “Performance-Graded Asphalt Binder Using Multiple Stress Creep Recovery (MSCR) Test.” About three years ago, a special provision was added to allow modification of binders GTR cross-linked with transpolyoctenamer rubber (TOR) with MSCR as an option to elastic recovery that requires polymer-modification. The NCAT test track results obtained for the SBS- and GTRmodified sections were an important factor in MoDOT’s decision to add GTR modification to the Missouri Standard Specifications. Based on information provided by a contractor who will remain anonymous, the typical savings are around $25 per ton of asphalt binder when GTR is used instead of SBS, but this number tends to change based on the market. On the other hand, SBS prices have increased more than 130 percent during the past several years, while the prices of crumb rubber have remained relatively constant. The bottom line is that both lab testing and field measurements showed that mixes containing GTR performed as well as, or in most cases, better than SBS mixes in the testing for this study. As a result, it appears that GTR can be used as a polymer substitute without sacrificing asphalt mix performance. Maria Carolina Rodezno is an NCAT lead engineer. For more information, you can reach her at (334) 844-4964 or visit www.ncat.us.
Mill Professionally for Better Project Success by John Ball
ne of the first steps in a recycling project is to mill an old or deteriorated pavement to a certain depth. A haul truck takes the millings away and the paving crew looks down the mainline and shoulder at the “new” surface to pave. Whatever the milling crew did or didn’t do when preparing this surface affects the paving crew’s job and the plant crew’s operation. Let’s look at the importance of a well-performed milling job on project management.
Step 1. Drive a Straight Line
We’ll talk about the benefits of automation in this section, but I want to remind foremen that operators need to have a guide to follow when running the milling machine. Don’t set your eyes on some point down the road or on the flag on the front of the milling conveyor. That flag is a communication device between the miller and the haul truck driver. What you want for the miller is something more stable. Not every job makes it feasible to spray a line of paint for the miller to follow. In the photos here, the job had a centerline to follow at first. Once you’ve milled up the centerline, using a laser or stringline is another option for staying on track. Use a guide bar on the front of the mill to follow the line. In photo #1 at top, you can see the guide bar is a simple rod of metal that is attached to the frame of the mill itself. It sticks out a few inches and is parallel to the pavement, giving the miller operator a “guide” to follow along the line on the roadway. You can purchase them with lasers installed; some have pointers. Or you can make your own for a 14 June/july 2012
simple match-up when driving down the lane. Automation gives the milling crew confidence in the depth they’re clearing, but not in the line they’re driving. Notice in these images that the crew is using LevelPro automation from Wirtgen America in photo #2 on page 15. It’s unique because you can run both sides—running grade on one side and slope on the other—all from the same unit. Keep in mind that automation can only correct what you physically allow it to correct. In this case, the crew had a 4-foot-wide shoulder and a 16-foot-wide roadway to mill. The 6 ½-foot drum shouldn’t have been used across the shoulder and mainline simultaneously. The foreman would have been correct to bring in a smaller machine to take care of the shoulder. Notice in photo #3 on page 15 that the expected and correct amount of
daylight is showing under the quality control-checking straightedge where the 4-foot shoulder lays. But we also see daylight under the straightedge at the edge of the mainline. That’s not correct and will cause the paving crew to demand more mix than the project originally called for from the plant.
Step 2. Watch Your Speed
We all know the pressures of production, but we also know that a professional job takes patience and attention to detail. When it comes to the milling portion of a project, you can’t rush it. If you drive the mill too fast, you can actually rip and tear the surface. We can’t go 120 feet per minute and expect it to look good. As discussed in the December 2011 issue of AsphaltPro, milling full depth at a nice and easy 60 fpm gives you the herringbone design that you
want to see behind the machine. Not every job will require that speed, of course. When only milling an inch in depth or when running slope, maybe you can achieve 70 fpm. Speed will also depend on the teeth in the drum. The average 360 perform differently depending on the brand and type. Let’s say you’re using a profile drum with 1,000 teeth; definitely slow it down! You’ll want to take that project at about 35 fpm so you don’t gum up the teeth. It comes down to common sense when you’re setting your speed for milling. Obviously, you don’t want to clog up the teeth. You don’t want to rip the surface. The whole point of milling is to bring back a true surface of crown and slope, which you can do with a speed set for quality, not maximum production. We could discuss safety at any point in a milling project procedural, so let’s go ahead and talk about it here. We’ve already discussed watching a guide bar in conjunction with a line on the pavement while adjusting automation and possibly bringing in a second, smaller mill to take care of shoulders on a project. Now we’ve added speed of travel into the mix. Miller operators have a lot on their minds concerning quality and production, but they must keep safety
in mind as well. Many companies can help with this by adding safety elements to their machines. Put orange guards on the tracks for safety. While few workers would reach into the track to remove debris, you never know when a ground man might trip next to the machine or stand too close with a loose rain
jacket or tool belt. The guard not only grabs attention, it keeps pinching pads from grabbing personnel. In photo #4 above, the subcontractor performing the milling on this project shows off a couple good safety additions. First, they’ve installed a lighted arrow bar on the large portion of the back end. Motorists will www.theasphaltpro.com | ASPHALT PRO 15
recognize the directional lights guiding them into—or reinforcing their use of—the correct lane. The subcontractor has also affixed a convex mirror near the top of the back end, between two orange strobe lights that they also installed. The mirror allows the operator to see into his blind spot behind the machine. The strobes give more illumination and signal to the ever-complacent driving public that this slow-moving vehicle and its workers are present. Way up in the front of this picture’s haul truck line, you’ll see the mechanic’s truck in the median. It’s also well-lit and on-site for any emergencies. As mentioned earlier, the tip of the conveyor chute has a flag for better communication to the haul truck drivers. Both workers in this photo wear their personal protective equipment. Notice that the morning of the milling operation is foggy. While you might think this would help keep milling dust to a minimum, it’s not an ideal working environment. A foggy morning presents limited sight for you and for the traveling public driving up on your work zone at a high rate of speed. 16 June/july 2012
Step 3. Broom it Immediately
Another step that helps make a safer environment and prepares the surface for a better project overall is sweeping. I can’t stress enough how important it is to get
the broom on the milled surface immediately after milling. I often recommend the milling crew have two brooms on the job. Brooming has to be done right away, as shown in photo #5 at left, so we don’t have dust lifting off the surface, causing danger for passersby and other workers. We also don’t want caked dust getting into the freshly milled grooves. That prohibits tack from sticking properly to all crevices in the surface. That prohibits the new asphalt from adhering and bonding perfectly to all grooves and crevices in the surface. So be sure the broom operator is working just as hard as the rest of the crew to make the project successful. Have a skid steer on hand to pick up piles of millings and stray chunks that the broom sweeps up. It’s a team effort to make sure the surface behind the mill is ready for top quality paving. John Ball is the proprietor of Top Quality Paving, Manchester, N.H. For more information, contact him at (603) 493-1458 or firstname.lastname@example.org, or visit www.topqualitypaving.com.
Mill to bring back the true pavement surface for a successful paving project and no surprise tonnages from the plant. Step 1. Drive a straight line. Step 2. Watch your speed. Step 3. Broom it right away.
Maintain the Crusher for Optimum Recycling by Wade Lippert
n any recycling crushing operation, maintaining your equipment is the best way to ensure the machine’s longevity and productivity. I recommend developing a maintenance program that fits the needs of your equipment and your operation. It’s important to set guidelines for operators to follow so here are my top five best practices to keep equipment up and running and make every operation more profitable. 1.) Safety should be the number one concern in every operation. Before an operator gets near the equipment to perform maintenance duties, he or she must understand the importance of lockout/tagout, the safety procedure that ensures that the power source is cut off and cannot be restarted before the service or maintenance work is complete. Lockout/tagout procedures are critical to preventing injuries and fatalities on the job site. 2.) Develop a maintenance program for all greases and oils. A maintenance program that details lubrication intervals, oil changes and filter changes is vital to keeping equipment running smoothly. Every piece of equipment has different needs, which is why it is important to follow the manual recommendations, but it’s equally as important to consider environment and application factors. You need to be conscious of the levels of dust and dirt, particularly when you’re dealing with asphalt. When asphalt dust and oils build up into the radiator, it affects the heat exchange of the radiator. When the asphalt enters a warm radiator, it tends to adhere to the cooling fins. Many times, it’s not even visible, but it’s important to maintain that at least daily. Use any citrus-based cleaner, like Citrus King or Astec Clean, to remove oils from the radiator. The best method is to let the radiator and equipment cool down, and then apply the citrus cleaner and rinse with cool water. It’s not easy to remove asphalt dust and oil from the radiator, and if you allow them to build up over time it becomes difficult, if not impossible, to remove them. If you implement a daily regimen for cleaning the radiator, it becomes very simple to stay ahead of the build-up and avoid radiator issues. Basic housekeeping rules apply here. The cleaner you keep your equipment, the better it can be maintained. 3.) Observe your equipment daily. As you are operating your equipment, it’s important to pay attention to the details—not only the way it looks, such as belt tracking, belt tension, oil temperatures, loose bolts and material buildup—but also the way it sounds.
20 June/july 2012
This blow bar shows minimal wear; it’s not quite ready for replacement.
This dirty radiator can be cleaned by cooling the equipment down, using a citrus-based cleaner and then rinsing it with cool water.
If you can catch something before it comes apart or breaks, then you can save yourself a lot of downtime. Sounds can be a great tool to use in predicting maintenance failures, such as squeaky bearings, metal rubbing on metal and high pitched noises that are out of the ordinary. As you notice crusher wear parts start to wear, it’s important to adjust the crusher’s settings to match your production requirements, particularly in recycle applications. Flip the blow bars or replace them when they reach the wear line on the back side of the blow bar. As an OEM we do not encourage going past this recommended mark, as this only leaves ¾-inch of blow bar remaining above the rotor. If exceeded, this will start wearing on the rotor itself and will dramatically affect
Recycled material (above) is ready to be processed. After it’s processed through an FT4240 impact crusher, it’s a more uniform size (at right).
crusher performance, i.e. production. As published in our manual, our crusher settings can be adjusted to one inch of the blow bar. With this being said, with crusher setting adjustments you can wear the blow bar down to ¾-inch from the outside diameter of the rotor. As for the wear liners, the producer can wear them down to half of the original thickness of the liner. This is due to the bolt that holds the liner to the hood. The bolt head wears along with the liner, and if left, could break off and fall into the crusher. If the liner is allowed to wear too thin, it could also break and fall into the crusher. Even if changing the blow bars or liners is expensive, you’re saving money in the long run. If the wear is accelerated by very abrasive material, then constant attention is going to be needed. By being attentive to your parts, you are going to keep your production high and minimize downtime. Keep in mind that in a recycle operation, the material can be extremely abrasive, and if it is, it may require more frequent crusher setting adjustments. 4.) Use low-chrome or medium-chrome wear parts in recycle applications. Blow bar metallurgy plays an important part in overall plant performance. Choosing the right metallurgy will reduce the amount of times one has to replace wear parts. Certain natural aggregates within the recycle may be highly abrasive and require a specific metallurgy to prolong the life of the blow bar. In certain applications where a high amount of steel is introduced into the crusher by means of rebar or mesh, operators should know that higher chrome content is not as tolerant to the introduction of metal into the crusher as lowchrome or medium-chrome options. 5.) Educate yourself on the product. While application is often not considered a maintenance issue, the two go hand-in-hand when caring for your equipment. For example, two of the most critical aspects of an
operation when making spec product in terms of productivity and wear of the machine are screen size and apron settings. Operators can optimize productivity in their crushing plants by using the machine’s top deck as a buffer deck whenever possible, thereby reducing carryover. Likewise, by maintaining proper apron settings, material can get through the machine in one pass, which also helps improve productivity and reduce wear. Maintenance is often thought of as merely lubrication, but how you use the equipment is a big part of maintaining the equipment. Oversized feed material can slow production and cause equipment damage, therefore causing downtime and incurring expense. So sizing material prior to feeding the crusher is vital to maintaining crusher longevity and increasing your crusher’s throughput. As an operator, your job is to maintain the equipment by operating it correctly. Education of the product is a good maintenance tool. The better understanding you have of how the equipment works, the better you are equipped to maintain it. Wade Lippert is a field service representative at KPIJCI and Astec Mobile Screens with more than 23 years on the job. For more information, contact him at (605) 668-2580 or WadeLippert@kolberpioneer.com or visit www.kpijci.com.
www.theasphaltpro.com | ASPHALT PRO 21
Add RAS with Accuracy, Assurance Overcome material challenges with quality control at producer level
22 June/july 2012
by Sandy Lender
f you wish to trim asphalt cement (AC) costs while keeping waste material out of landfills, you’ve probably looked into the recycled asphalt shingle (RAS) availability in your area. With the quality control (QC) issues of bringing in clean RAS and having it ground to the finest size you can get, you may have run into the challenge of weighing that material accurately throughout the mix design and mix production phases. Not to worry. Producers in the field have met with some challenges when it comes to handling RAS and they have tips and advice to help their peers ensure a quality mix for customers, owners and agencies. Let’s begin looking at this topic by addressing some of the QC aspects to watch for when working with a finely ground recycle material such as RAS. First, remember that the amount of recycled AC you get out of RAP is a different percentage than what you get out of RAS. Even the amount of AC in RAS can vary from 15 to 35+ percent. That means your plant operator has much to track when it’s time to produce mix with recycle in it. Of course plant manufacturers and controls OEMs are part of the solution. Rick Tapia of Stansteel Asphalt Plant Products, Louisville, Ky., brings up an interesting point for the discussion of handling RAS separately from RAP. “Initially, it’s very important to know the difference between excess manufacturing tabs on the one hand and recycled
shingles from a roof tear-off on the other hand,” Tapia said. “These two types of shingles must be handled, fed, metered, proportioned and blended in different ways. For example, your RAP bin is separate from your RAS bin. If that’s the case, shouldn’t you also separate never-used shingles from worn-out shingles?” The big question producers in the Midwest have asked of Clarence Richard, proprietor of Clarence Richard Co., Hopkins, Minn., concerns measuring what comes out of the separate bins. What he discovered in working to resolve their measuring issue was an accuracy issue. Quality control of RAS needs a delicate touch. “Most producers are trying to weigh RAS using the existing RAP feeder system that they have without making any improvements,” Richard said. “There are a few reasons that producers will want to update existing equipment for RAS. First, RAS carries a lot of AC in it. When accuracy is off, the AC content is affected by the error more than when RAP’s accuracy is off.” Richard’s second observance should encourage producers to look not only at multiple bin use for multiple products, as proponents of fractionated RAP have said for years, but also to look at multiple scales that the control house can read. His third should encourage producers to look at equipment shape. “Second, sometimes producers use multiple bins in series with a RAP scale
During the demonstration, Henningsen Plant Manager Duane Updike observed the bin flow rate change from plus or minus 15 percent while the feeder speed ran at a constant speed. The same 15 percent deviation was observed at flow rates as low at 6.75 TPH to 25 TPH. Photos courtesy of Clarence Richard Co.
www.theasphaltpro.com | ASPHALT PRO 23
Left and Below: Clarence Richard suggests producers place a strip of conveyor belt or similar material alongside the EZ-Flo scale to prevent wind from affecting its delicate operation. Of course, you’ll want to add that encumbrance after you get the scale into this tight space. Photos courtesy of Clarence Richard Co.
Below: Henningsen Plants Superintendent A.J. Dennis Campbell points out the installation of the EZ-Flo scale. Photo courtesy of Clarence Richard Co.
with RAP in one of the bins and RAS in another,” Richard continued. “They can’t be sure how much is coming out of either bin at any given time. The RAP conveyor was built for heavier TPH flow rates (25 to 125 TPH) of RAP productions. Current RAS rates require weighing product from 5 to 25 TPH. That’s a big difference. The RAP scale system (conveyor included) was not built to accurately weigh material at such a low flow rate. 24 June/july 2012
“Third, when you have multiple bins in series with a RAP scale system, there’s no way for the blending control to adjust for bin speed when one of the RAP bins or RAS bin clogs up, or density is changed. And density can change plus or minus 15 percent. Some belt scale manufacturers advise against using their scale to weigh light-loaded products for such a critical application.” To address weighing RAS separately, Richard brought up the
Dual recycle bins often mean the producer fractionates his RAP and treats it with the same care he treats virgin aggregate. That’s an excellent practice. When he decides to use one of the recycle bins for a much finer product like RAS, quality control management needs to take a step up. Photo courtesy of T.J. Young of T2ASCO.
Keep in mind that continuous weigh scales and metering instruments should be checked for accuracy. The accuracy of the check is only as good as the resolution of the instruments being used, the size of the sample and the sampling method. In this photo, an 8-ton sample is gathered, which is better than a 4-ton sample. The procedure was to collect material in a truck after the material had traveled more than 100 feet of conveyor and through a scalping screen. Photo courtesy of Clarence Richard Co.
EZ-Flo continuous weigh flow scale (Impact Plate) that his company manufactures. To address flow and controls, a variety of sources discussed controls and equipment use. The flow scale from Clarence Richard Co. works much like a belt scale except it doesn’t need a tachometer. It already “knows” the speed of the material passing through it is constant—gravity. The flow scale reads the rate of material flow as it impacts the front face of the impact
plate. The rate reading, in TPH, indicates how fast material is passing through the flow scale and produces an output signal useful for blending materials. The totalizer reading, in tons, is used for calibrating the scale, cross-checking accuracy, inventory control and producing a signal capable of batching product. The flow scale impact plate is mounted 6 inches away from the end of the belt feeder head pulley to measure the RAS flow rate. www.theasphaltpro.com | ASPHALT PRO 25
When Henningsen Construction had the gravity-fed RAS impact scale EZ-Flo installed, visitors from Curran Contracting, Gallagher Asphalt, Healy Construction, Oldcastle Materials, Plote Construction and the Illinois DOT stopped by for a demonstration of its RAS-measuring abilities. From left: Joseph Rechner, Steve Hafel, Ryan, Tu, Curran QC Manager John Lavallee, Henningsen Plant Manager Duane Updike, Pete Lochner, Jesse Simmons and Tim Smith. Photo courtesy of Clarence Richard Co.
A.J. Dennis Campbell, plants superintendent for Henningsen Construction, Atlantic, Iowa, shared that he had concerns when his company won a 60,000-ton job that required about 4 percent shingles. The job was in Iowa, but on the Illinois border, so two groups took an interest when Campbell gave the go-ahead for an EZ-Flo to be designed, built and delivered in four weeks. He wanted an accurate means of weighing RAS material as it discharged from the RAS feeder belt to the collector belt. The distance between the RAS feeder head pulley and the RAP tail pulley— and both of their support structures— is 20 inches. The distance between the bottom of the feeder belt and the center of the collector belt was 12 inches. The troughing rollers used up part of that 12-inch space. The RAP bins also have bin support structure and bin feeder conveyor drive pulley-sprocket arrangement on one side of the bin and the loader ramp barricading access to the confined space. That meant the
RAP and Shingles over the same Belt Scale. You have a problem.
Fiber, Dust, Hydrated Lime, etc.
Now Shingles from... EZ-FLO Feeder Scale
Assembles inside the confined space between feeders
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team assembled the scale inside the confined space as much as possible. With the careful operation done, the EZ-Flo can be used at the Henningsen operation for fine RAP and RAS monitoring. An operator can slide the scale out of the flow when using the bin for RAP. With visitors looking on, Henningsen Plant Manager Duane Updike observed flow rate changes during production with the EZ-Flo in place. The impact scale located in the control house reads in real time and would normally be monitored by the plant computer. “Plant computers are programmed to either compensate for the AC when the RAP scale deviates from a set point or to increase or decrease both feeder bin speeds,” Richard reminded us. “Either way, one scale is not enough. Now, the mix producer has the option of weighing the RAS and controlling that bin or the AC being added to the mix. The same RAS rate signal being used to control for the RAS can be subtracted from the RAP belt scale—which
is weighing both RAS and RAP—to indicate the actual RAP TPH flow rate.” This means the plant computer can use RAP deviation information to adjust the oil being added to the mix or the RAP feeder speed. “Contractors should give a heads up to their blending control manufacturers about the changing requirements they’re asking of their blending controls,” Richard said. “Today’s blending controls aren’t usually set up with the software to accept another scale input or two to monitor the flow with a continuous weigh RAS scale and, consequently, control the flow from that scale information.” That means it may be time to contact your controls OEM to get analog inputs for a new scale. Jim Richwine, director of engineering for Libra Systems, pointed out the importance of connecting new technology with new technology. “Most plant operators open the gate on RAP bins much wider than would normally be done for volumetric control,” Richwine said. “They do this to
prevent bridging, but in the process, they hinder traditional volumetric control because the material is then not cut by the gate. Instead, the material pours from the bin and the amount produced by the bin for each revolution of its belt actually varies as the belt speed changes. So, the old-style control systems that used a single ‘pounds per tach pulse’ calibration for the bin became inaccurate at different speeds." Richard concurs with Richwine that multi-point calibration is better than single-point volumetric calibration, but he says that volumetric control of any type is unacceptable for RAS. The demonstration mentioned previously proved that RAS controlled volumetrically was wandering all over the map. “RAS density changes plus or minus 15 percent,” Richard reminded us. “Therefore the accuracy of weighing material volumetrically is plus or minus 15 percent.” Any QC manager can tell you what that range does to voids. Getting the gate, and indeed the entire bin, in position for the new material,
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is T.J. Young’s primary concern. He’s the proprietor of T2ASCO and recommends producers ask about cold feed bin enhancements before purchasing more bins for recycle storage. We’ve already established that a fine material with high moisture and angular shape such as RAS will have a tendency to bridge in its bin. Young gives producers a bin style to look for to keep bridging at bay. “Over the last 30 years, all main-line hot mix equipment manufacturers have embraced the following design elements, often borrowing from each other, to help improve feed characteristics and reduce bridging problems,” Young said. “They build with steep side walls of typically 60 degrees or above. They keep a long opening at the bottom of the bin and a trapezoidal shape to the opening. And they use vibrators or air cannons that can be activated at loss of flow.” Whatever bin “style” a producer has in place, the control house has to get good information from it. “Because of the importance of maintaining a quality product through the proper blending of materials, it is essential to have electronic controls and interlocks to properly monitor the RAS feed rate,” Tapia said. “The Stansteel Accu-Track with Closed Loop Control System is an example of such a control system. With many control systems, a signal is sent from the processing unit to feed at a certain rate. However, with the AccuTrack System, the rate of flow is verified and deviation alarms alert the operator to any problems. Another important aspect is factoring in the asphalt percentage—that’s true for either RAP or RAS percentages. The percentage of liquid asphalt in recycled shingles can vary from 15 to 38 percent. In addition to being able to input varying amounts of asphalt percentage in the RAP and RAS ingredients, it is also important to know the rate of flow and have sequential timing in place to track the travel time of each RAS and RAP ingredient, as well as other aggregate ingredients, so that they all hit the mixing, proportioning and blending phases in a planned and quality-controlled manner, resulting in a quality product.” Libra’s Richwine pointed out that these worries for a drum plant are somewhat lessened with a batch plant. “Since batch plants, with a separate RAP scale, weigh each material one at a time, bridging doesn’t affect the mix content. It merely slows the weighing of the batch.” That seems to make Richard’s point perfectly. Weigh and measure each element and be sure the controls system has a way to incorporate that data. Above all, make sure the team “at the wheel” is your best. “Nothing beats an alert operator and control system,” Richwine concluded. “But modern controls ameliorate the situation with automatic attempts to break the bridging and control techniques that still make the best mix possible.” The best mix possible is the hallmark of the asphalt industry. www.theasphaltpro.com | ASPHALT PRO 29
Call Congress Now
Here’s how to make your voice heard in the highway funding battle by Sandy Lender and Jenny Williamson
e’re not going to mince words to make this a fluffy highway funding piece. Straight up, here are the tools you need to write a letter or make a call to the representatives who will make a difference in your bottom line by June 30 when the extended SAFETEA-LU expires.
By the time you receive this magazine, you’ll have about three weeks—by June 20—to make sure the conferees listed herein know you want them to reach a consensus on MAP-21, also known as S 1813. We’re getting this edition out the door early to give those of you who don’t follow us on our social media platforms maximum planning time. So let’s get down to business.
House Conferees, Transportation Committee
John Mica (R-Fla.) Nick Rahall (D-W.Va.) Don Young (R-Alaska) John Duncan Jr. (R-Tenn.) Bill Shuster (R-Pa.) Shelley Moore Capito (R-W.Va.) Rick Crawford (R-Ark.) Jaime Herrera-Beutler (R-Wash.) Larry Bucshon (R-Ind.) Richard Hanna (R-N.Y.) Steve Southerland (R-Fla.) James Lankford (R-Okla.) Reid Ribble (R-Wis.) Peter DeFazio (D-Ore.) Jerry Costello (D-Ill.) Eleanor Holmes Norton (D-D.C.) *Jerrold Nadler (D-N.Y.) Corrine Brown (D-Fla.) *Elijah Cummings (D-Md.) Leonard Boswell (D-Iowa) Tim Bishop (D-N.Y.)
http://mica.house http://rahall.house http://donyoung.house http://duncan.house http://shuster.house http://capito.house http://crawford.house http://herrerabeutler.house http://bucshon.house http://hanna.house http://southerland.house http://lankford.house http://ribble.house http://www.defazio.house http://www.costello.house http://www.norton.house http://nadler.house http://corrinebrown.house http://cummings.house http://boswell.house http://timbishop.house
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Energy and Commerce Committee Fred Upton (R-Mich.) Ed Whitfield (R-Ky.) *Henry Waxman (D-Calif.) Natural Resources Committee Doc Hastings (R-Wash.) Rob Bishop (R-Utah) *Ed Markey (D-Mass.) Science, Space and Technology Committee Ralph Hall (R-Texas) Chip Cravaack (R-Minn.) Eddie Bernice Johnson (D-Texas) Ways and Means Committee Dave Camp (R-Mich.) Patrick Tiberi (R-Ohio) *Earl Blumenauer (D-Ore.)
http://camp.house http://tiberi.house http://blumenauer.house
*Those with an asterisk voted “no” to H.R. 4348. For a full list of representatives who voted against the 90-day transportation funding extension, visit http://www.asphaltpavement.org/images/stories/hr4348_no_votes.pdf on NAPA’s website. 30 June/july 2012
At this point in history, the members of Congress are inundated with e-mail on a number of legislative topics. According to ConservativeUSA.org, congressional representatives no longer use actual email addresses; they have switched to contact forms found on their websites and many of them require zip code entry for verification. Jay Hansen, NAPA’s vice president of legislative affairs suggests industry members take a more noticeable route in reaching representatives. Write a letter to them or pick up the phone and call them. While scheduling an appointment to meet with a representative in his or her office in D.C. or when he or she is in the home district is a great way to reinforce your message—and providing a facility tour where the elected official gets to shake hands with many constituents at once, preferably in front of news cameras, is the ultimate invitation—we’ve run out of time for such pleasantries. Here are two portions of the sample e-mail from the NAPA site that the organization has prepared so that you can write to your legislators. (Review the entire letter, or send it through the website from the “Legislative Action Center” under Government Affairs on www.asphaltpavement.org.) You could use this to draft your letter that you mail or fax today to any of the representatives listed above, or to the representative you fear will vote against your livelihood in mid-June.
32 June/july 2012
“I am writing to urge you to take up and vote on H.R. 7, the American Energy and Infrastructure Jobs Act. H.R. 7 is a bill that will provide jobs in the transportation construction industry and offer certainty for state transportation departments to put out highway projects through 2016. The Senate has passed its bill, S. 1813 by a vote of 74 to 22. The House of Representatives needs to complete consideration of H.R. 7 so it can go to conference with the Senate and ultimately be enacted into law. … “I know the funding issue is very difficult, but that is no excuse for not moving H.R. 7. The legislation is paid for and needs to advance in the legislative process. … My job depends on it.” For additional facts to include in your letter, visit the National Transportation Research Group’s page at www. tripnet.org/state-info-reports.php for info reported for individual states. You can do as Hansen suggests and make the information in your letter “local” for your representative. Or visit www.asphaltpavement.org/images/stories/napa_talking_points_as_of_april_2012_final.pdf to get two pages of facts that summarize the problems industry faces and the way your representative can come to the rescue. Time is short. Your voice matters as your elected officials decide how to proceed with highway funding. If all you have time to do is send an e-mail, you’ve still contributed to the effort of educating the decision-makers. We’ll re-visit this topic in the August issue to see how Congress behaved.
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New Binder Allows Thinner Pavements That Resist Cracking, Rutting Editor’s Note: This two-part presentation of Kraton Polymer’s new highly polymer modified asphalt (HiMA) binder begins with the latest test results NCAT’s Pavement Test Track. The results were released during the Pavement Test Track Conference Feb. 28 through 29 in Auburn, Ala. The second part, beginning on page 38, tells of the new binder’s use in Oklahoma this April.
newly developed asphalt binder allows the use of thinner pavements while resisting cracking and rutting, according to results of recent research at the Pavement Test Track of the National Center for Asphalt Technology (NCAT). The findings from the 2009-2012 cycle at NCAT’s test track in Opelika, Ala., show that an experimental pavement section incorporating highly polymer modified asphalt (HiMA) binder experienced less than one-third the wheelpath rut depth of the track’s control section, which is 18 percent thicker than the HiMA test section.
HiMA Boosts Polymer Content
Preparation for the latest cycle involved the reconstruction of 17 test sections in August 2009. One of the sections was North 7 (N7), which incorporates HiMA technology developed by the section sponsor, Kraton Performance Polymers. For detailed information on the test track’s construction and testing, check out the online HiMA package at www.TheAsphaltPro.com. Kraton developed this technology to improve pavement durability and resistance to rutting, shoving and cracking, while reducing pavement thickness. This technology employs significantly higher polymer dosages than those ordinarily used. Usually, as polymer content in asphalt binder exceeds 3 percent, binder viscosity begins increasing, eventually reaching a point where plant hot mix asphalt (HMA) becomes difficult to make and increasingly unworkable for paving crews. To overcome this limit, Kraton developed D0243 polymer, a modified styrene-butadiene-styrene (SBS) copolymer that can be blended with asphalt binder at dosages of 7.5 percent and higher, gaining the benefits of increased polymer content without increased binder viscosity. To field test this new technology, Kraton engaged NCAT to build Section N7 using the same Superpave methodology as Section South 9 (S9), the track’s control section, but using HiMA binder containing 7.5 percent D0243 polymer instead of performance grade (PG) binders modified with standard SBS. Mix design, design gyrations and other factors were kept the same as the control section so the only variables would be the binder and the thickness of the layers. Section N7 pavement is 5.75 inches thick, which is 18-percent thinner than the 7-inch-thick control section. N7 pavement consisted of three lifts of HMA, each employing HiMA 36 June/july 2012
by Paul Fournier
binder containing 7.5 percent SBS. The nominal 2.25-inch base layer and 2.25-inch middle layer each incorporated 4.6 percent HiMA binder and 19-mm stone, and the nominal 1.25-inch top layer incorporated 6.3 percent HiMA binder and 9.5-mm stone. For comparison, control Section S9 has a nominal 3-inch base layer incorporating 4.7 percent of PG67-22 binder and 19-mm stone, a nominal 2.75-inch middle layer incorporating 4.4 percent of PG76-22 (modified with SBS) binder and 19-mm stone, and a nominal 1.25-inch top layer incorporating 6.1 percent of PG76-22 (with SBS) binder and 9.5-mm stone.
HiMA Outperforms Control Section
Ergon Asphalt & Emulsions supplied HiMA binder from its Memphis, Tenn., facility, where D0243 SBS polymer in pellet form was added to liquid asphalt to produce the 7.5 percent SBS concentration. HiMA binder was shipped to East Alabama’s Astec Double-Barrel plant, located just 11 miles from the track. The plant operator manufactured HMA at temperatures between 171°C (340°F) and 174°C (345°F). Arriving at the track, delivery trucks discharged their loads into a Roadtec SB2500B material transfer vehicle, which provided a steady supply of mix to a Blaw Knox PF3200 paver. Three rollers compacted the mat: a Dynapac CC522 vibratory breakdown roller; an Ingersoll Rand pneumatic intermediate roller; and a Galion 712 static steel drum finish roller. The average mat compaction measured between 92.7 and 93.7 percent. No procedural changes were necessary in producing HiMA mix at the plant or in placing the material by the paving crew. Truck trafficking for the 2009-2012 cycle concluded in September 2011 when the goal of 10 million ESALs was achieved. NCAT researchers studied accumulated data and arrived at conclusions, which were subsequently presented at the February 2012 Test Track Conference. One of the most significant findings was that the average wheelpath rut depth of the N7 HiMA section was less than a third of the control section. Specifically, the rut depth of Section N7 was 2.2 mm (0.09 inches), while that of the S9 control section was 7.1 mm (0.28 inches). Also of consequence: surface crack mapping of N7 pavement had not shown any pavement cracks.
HiMA-Repaired Section Outperforms Control
An adjoining test section—the Oklahoma DOT-sponsored Section N8—provided further evidence of HiMA binder effectiveness. Check out the online HiMA package at www.TheAsphaltPro.com for the details.
A Haskell Lemon paving crew uses a vibratory tandem roller in breakdown position on a 1.5-inch HiMA-rich intermediate layer (RIL) on I-40 in April 2012.
Oklahoma Anticipates I-40 Performance Gain with HiMA by Tom Kuennen
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Haskell Lemon’s milling crew cold-mills the shoulder of I-40 in advance of HiMA paving.
klahoma Department of Transportation (ODOT) officials have high hopes for a mill-and-overlay of I-40 just west of Oklahoma City that incorporates highly modified asphalt (HiMA) pavement. ODOT is using HiMA on I-40 in Caddo County in the first commercial application of this new technology. Work on this project began with traffic crossover placements in February 2012, followed by mainline milling and paving through April. Use of the HiMA mix should enable the DOT to obtain a durable asphalt pavement with a possible reduced pavement depth, saving money and permitting the DOT to pursue a larger resurfacing program with the same amount of funds. In Oklahoma, a single, highly modified PG76-28 E binder was used for three different asphalt mixes for I-40. The HiMA binder contained 7.5 percent SBS (styrene-butadiene-styrene) polymer, more than twice as much as that used in conventional polymer-modified binders. While it’s common industry knowledge that modification of liquid asphalt binders with polymers improves resistance to rutting and raveling of asphalt mixes, there is a practical limit to polymer concentration. Usually, as polymer concentration exceeds
3 percent, the viscosity of the binder increases such that the mix becomes more difficult to produce in the plant and less workable for the paving crew. However, the polymer used in the Oklahoma I-40 PG76-28 E binder was Kraton™ D0243, a new SBS product manufactured by Houston-based Kraton Performance Polymers, Inc. “It was our hope that instead of doing a traditional, thicker overlay or inlay, that we could reduce that depth,” Jeff Dean, Oklahoma DOT pavement engineer said. “We knew that the highly polymerized mix was going to be more expensive, but we felt that the cost of the HiMA versus a reduction in the required thickness would offset each other, while giving us a longer-life pavement.”
HiMA Reduces Lift Thickness
ODOT moved forward with use of the highly modified asphalt binder without in-field testing, as it had seen how HiMA performed in sections in the National Center for Asphalt Technology’s Test Track (See article on page xx). “At the NCAT test track we can look at how pavement sections will perform over the short two-year high
volume traffic loading cycle,” Kenneth Ray Hobson, bituminous engineer for ODOT’s Materials Division said. “At the test track we found that the HiMA was a good repair option to resist rutting and bottom-up shear cracking. Since it worked well at NCAT, we decided to try it on I-40 where we have rutting and cracking. We think that it will do as well here as there.” This project improves a 2-mile section of I-40 at the eastern end of Caddo County, Dean said. “We had two test sections at NCAT in which we were looking at perpetual pavement designs,” Dean said. “We built a thick section, and one that was thinner that we knew would fail earlier. We did not know when it would fail, but wanted to see how thin we could build it but still have it considered a perpetual pavement. It failed within three years, with cracks developing from the bottom up. We tried a number of repairs, including the use of reinforcing fabrics, but they did not perform as expected. The section was adjacent to a group-funded section in which the Kraton HiMA mix was placed. It had been performing very well, so NCAT’s assistant director Buzz Powell suggested we try this HiMA to repair our section that had failed. It’s performed very well for us since.” On I-40, the DOT anticipates that the new HiMA binder will improve performance, while quelling fatigue cracking and rutting. “The 8-inch HiMA should perform as well as what I would typically expect for a 10.5inch pavement based on the data from the NCAT test track sections. Of course this is just my estimate,” Hobson said. In Caddo County on I-40, cold milling of aged asphalt preceded the new HiMA lifts. “On this pavement we are milling-and-filling 5 inches, but we are adding an additional 3 inches, plus a 3/4-inch open graded friction surface course (OGFSC), typically called a ‘popcorn’ mix,” Hobson said. That OGFSC will get a standard PG76-28 OK—OK as in “Oklahoma’s PG+ specification”—binder. continued on page 42 www.theasphaltpro.com | ASPHALT PRO 39
continued from page 39
New Testing Protocol
The “E” in the PG76-28 E rating designates a new multiple stress creep recovery (MSCR) testing protocol, and stands for “extremely high grade.” The mix designation suffixes are S (standard), H (high), V (very high), and E (extremely high) grades for increasing traffic loads and volumes. “It provides additional testing parameters,” Hobson said, “including a percent recovery parameter, which has the potential of replacing our PG+ test for elastic recovery. MSCR was the best method to characterize the HiMA binder used on this project. This binder was required to have a minimum of 95 percent recovery at a stress level of 3.2 kPa.” The contractor placed one 1.5-inch HiMA rich intermediate layer of 3/8inch NMAS on the milled, tack-coated surface. They followed that with two 2.5-inch lifts of Oklahoma S3 base course, which is a HiMA with 3/4-inch NMAS gradation with 100 percent passing the 1-inch screen. These were topped with one 1.5-inch lift of Oklahoma S5, a HiMA with 3/8-inch NMAS gradation with 100 percent passing the half-inch screen. Finally, these HiMA lifts were to be topped with the open-graded friction surface course. As a pavement bends under loads, the maximum tensile stress will occur in the bottom lifts. Any resulting cracks at the bottom can migrate upward to become fatigue cracking at the top, Hobson said. “If we can add more polymer modified asphalt, it gives us a chance to ‘heal’ that bottom lift and not initiate a crack there,” he said. “I-40 fits into the concept of the perpetual pavement, as we have a rich bottom layer to which we add more asphalt binder. The HiMA throughout gives us more elastic components to resist that tension that can cause cracks at the lowest level. “If the thinner pavement thickness design for this project works as expected,” Hobson continued, “we will not need to replace the entire pavement structure. This could save 42 June/july 2012
The Sakai rubber-tired compactor provides finish rolling of I-40 HiMA mat.
On a sunny spring afternoon, dry ice chills the hot mat in advance of coring. The core samples of the Oklahoma I-40 HiMA mat will be analyzed in labs across the United States.
significant time, effort and money. It should be very fatigue-resistant because we have that high polymer content. It should be rut-resistant and resistant to cracking, provided that we have a thick enough layer and some stress relief at the bottom of the maximum tensile stress. Will this pavement design be perpetual? We don’t know yet. This is why we will continue testing during the next NCAT cycle.” “Our goal is to make pavements more cost-effective overall,” Bob Kluttz said. He’s a senior scientist, Research and Development, at Kraton
Polymers. “Even though polymers are expensive, and we’re putting a lot more into these mixes, if we can get a thickness reduction of asphalt pavement—from 10 inches depth to as much as 6 inches depth—we’re actually making the pavement cheaper up front.” Conventional polymer modifier products, when used in high percentages, result in a mix that is too viscous and hard to compact, Kluttz said. “In HiMA we’ve developed a polymer that has a low-enough viscosity that you can use it in high percentages and the
The HiMA mix containing Kraton D0243, a new SBS modifier, is fed under the screed to lay a durable asphalt pavement with a 30 percent reduced pavement depth, which saves money for the Oklahoma DOT.
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mix still will be workable and compactable.” HiMA thinner lifts that perform as well as conventional thicker lifts have an added benefit: they don’t require modifications to existing pavement grades. “An advantage of the thinner inlay is that you don’t have to worry so much about grade changes along the highway section,” ODOT’s Dean said. “You don’t have to readjust guard rail or cable barrier. You don’t have to tear out so much under overhead bridges. A thinner inlay eliminates a lot of secondary problems.”
HiMA on Oklahoma I-40
Highly modified mixes using conventional polymers may retain workability if produced at very high temperatures, in the neighborhood of 370 to 380oF, but that leads to excessive fuel costs and premature aging of binder, Kluttz said. HiMA for the Oklahoma I-40 project was produced at 325oF. The I-40 project used some 1,500 tons of liquid asphalt, equivalent to 30,000 tons of mix, for about three months of paving. Existing asphalt was milled-out 5 inches deep prior to paving. According to Stuart Gragg, project manager for Haskell Lemon Construction Co., Oklahoma City, the final ‘popcorn’ OGFSC lift also will contain a conventional PG76-28 binder. “Traditionally, popcorn is a sacrificial layer and doesn’t last more than 7 to 8 years on average,” Hobson said. “If we can get 10 or 12 years out of it, that would be great.” In the next NCAT test track cycle, Oklahoma hopes to evaluate a new OGFSC. Oklahoma DOT likes the OGFSC mixes because they provide high friction and good drainability of rain and melt water, which all but eliminates aquaplaning and truck tire spray. “The popcorn mix does not add much to structural strength, and we don’t use it in the computation of structural strength,” Hobson said. “Even though it provides some structural strength we ignore it, and use it for safety reasons.” “We have three PG76-28 E mixes,” Gragg said. “One is a rich intermediate 44 June/july 2012
The Haskell Lemon crew hauled the Kraton™ D0243 HiMA mix to a Roadtec Shuttle Buggy, which delivered it in a smooth, steady flow to a hopper insert in a Cat AP1055B paver. The Dynapac double drum roller served in the breakdown position.
Haskell Lemon Gives ODOT Success Story by Sandy Lender Producers might wonder how an asphalt binder modified with more than twice the typical polymer content for a PMA might work out. For the Haskell Lemon Construction Co., Oklahoma City, the 7.5 percent styrene-butadiene-styrene (SBS) polymer that makes up the new D0243 HiMA from Kraton was businessas-usual. Good business. The Oklahoma Department of Transportation (ODOT) let a 2-mile project that specified the use of the HiMA. Haskell Lemon’s President Jay Lemon said they won the bid and moved their CMI 450-TPH portable drum plant to the site. He stated they located the plant within half a mile of the end of the job, which took long haul times out of the equation. “Because of our unfamiliarity with the product, we went ahead and put the money into minimizing the problems we could minimize to make the project the best it could be for ODOT,” Lemon said. “With what we perceived was going to be a little more difficult product to work with, we wanted to have all the tools in place for success.” Contractors should look to partners and vendors as excellent tools for success. In this case, Lemon said they worked with their AC supplier to keep the HiMA product in perfect condition for step one—making mix. “We went into the project working very closely with our AC supplier—Lion Oil. We had a verbal agreement that we would keep our production needs close to one another and try not to store this material very long. Our goal was to use just in time inventory and not to hold much of the AC overnight. Lion supplied us great materials and the transportation company did their part well, which allowed Haskell Lemon to succeed. We did communicate with Lion much more that we usually do with our liquid suppliers.” The other tools are more obvious. Haskell Lemon used a material transfer vehicle for all lifts of the 2-mile project although ODOT only required its use on the surface course. “We consider it just another tool that helps eliminate errors. For this project it contributed to the quality we were after.” Overall the production and paving crews didn’t have a frightening monsterof-a-binder to prepare for. “We found it no more difficult than a typical ODOT PG76-28,” Lemon said. “That’s the highest grade binder ODOT has.” He described the PG76-28 as “superdosed” when the Kraton polymer was added. “It was a positive experience for us; working with the product and getting good compaction numbers on the road.”
layer (RIL) lift, one an S5 (3/8-inch NMAS) lift, and then an S3 (3/4-inch NMAS) lift.” When visited in late April, the RIL was being placed on the eastbound lanes of I-40. It’s a 3/8-inch NMAS mix, running 5.6 to 5.8 percent HiMA, being placed 1.5-inch deep on the milled, tack-coated surface, and compacted to 94 percent. Compaction target is 94 percent for each lift. The contractor can go as low as 93 percent or as high as 97 percent, but the target is 94 percent. “I expect to see an asphalt pavement that’s a lot more resilient, something that’s stronger and stiffer that will last a lot longer by being rut-resistant,” Gragg said. “Superpave designs, together with this highly modified AC, will help us prolong the lifespan of this pavement. And hopefully the RIL and its HiMA PG76-28 E binder inside will help us fight fatigue cracks. If we can go from a 10- to 12-year life span on an overlay to a 15 to 20, that will save a
lot of dollars as far as state expense on maintenance.” In late April, good weather was propelling the project onward, onschedule. A material transfer vehicle was being used to quell mix segregation and provide a more uniform surface. “The project’s been going well,” Gragg said. “We’ve had pretty good weather with minimal breakdowns. The asphalt has placed well and our densities are what they should be.” The project was of such a high profile that it was being closely studied by personnel of ODOT, the Oklahoma Asphalt Pavement Association, The Asphalt Institute, and the Federal Highway Administration. Core specimens from the first day’s work were shipped to FHWA’s Turner-Fairbank Highway Research Center outside Washington for analysis. “They will be running some tests for us and hopefully we’ll have some data regarding modulus values of these highly polymerized mixes, so
we can do a more in-depth analysis of anticipated design life,” Dean said. “If we can get the costs down by using a thinner HiMA asphalt inlay, then we can reduce our overall costs, allowing us to repair a lot more of our interstate and state highways. It could help the division engineers stretch their budgets further.” ODOT isn’t done with HiMA. “We’d like to find another section where HiMA would be a good fit,” Hobson said. “While this I-40 project is actually an 8-inch project, we’d like to find a 5-inch section for mill-andfill that would replicate what we did at the NCAT test track. Otherwise, we will wait a while and see how this I-40 project performs.” “We hope HiMA will allow us to put in roads that last longer, and won’t have to be repaired as often,” Kluttz said. “That’s going to allow the states to get caught up in all the work that they are way behind on, or allow them to get caught up on new construction.”
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South Africa Recycles with RMB by Richard Champion
Richard Champion, Director of International Sales for CEI Enterprises, Inc.
uring the Institute of Quarrying South Africa and the Aggregate & Sand Producers Association of South Africa’s annual conference April 19 through 20 in Umhlanga, I had the opportunity, as a guest of Osborn Engineering, to discuss the country’s science of rubber-modified bitumen (RMB). As researchers have found in the United States, successful RMB production relies on proper heat management and offers multiple pavement rewards. With RMB, the virgin asphalt temperature must be greater than 190oC (374oF), and the aggregate temperature is about 163oC (325oF) for the HMA production. At the paving site, the breakdown roller hits the mat when it’s a temperature of 143oC (290oF) and the ambient temperature is greater than 13oC (55oF) to ensure a satisfactory project. For further success, you want an experienced binder/job mix designer, an experienced asphalt rubber (RMB) blender and HMA producer on the project. Make sure the asphalt plant has compatible electronics for RMB production. Get an on-site quality control (QC) technician who can communicate with a knowledgeable agency inspector. Above all, as always in 46 June/july 2012
HMA production, use good common sense. I mentioned the need for an experienced RMB blender for a good reason. One of the disadvantages of RMB is that it requires a blending unit or pre-blended binder, and then it requires an agitated, properly heated, binder storage tank at the plant. This hasn’t stopped RMB from being used in North America, Europe, Australia, South Africa and Angola, China, Israel, and Brazil. All producers need is a quality built mixing system and a reaction tank to complete the process of preparing RMB for the asphalt plant. First, the RMB crew adds ground tire rubber (GTR) into the feed hopper of the mixing system. On a typical system, load cells monitor the volume by weight of GTR. An auger conveys the GTR from the feed hopper to the mixing can. Bitumen enters a booster heat exchanger where the liquid’s temperature is elevated as much as 37.8oC (100oF). The heated bitumen is then pumped through a Micro Motion Asphalt Meter then into the mixing container where a high-shear mixer blends the GTR and bitumen at a speed of 3400 rpm—proper contact and mixing of the materials is then assured. The blended bitumen and GTR are then pumped into a reaction tank where mixing augers and heating coils keep it agitated and hot while it undergoes the agency specified reaction time. For instance, CALTRANS requires a 45-minute reaction time while Arizona stipulates a 60-minute period. Finally, the fullyreacted RMB exits the reaction tank and is pumped directly to the HMA plant for the production of rubber hot mix asphalt (RHMA). Experienced RHMA producers prefer to have a dedicated RMB pumping/ metering system due to the inherent abrasive nature of RMB.
The RMB content in the RHMA is usually in the range of 7.3 percent up to 8.5 percent depending on the aggregate mixture. Open graded and fraction course designs are the most popular. RMB allows substantially higher bitumen content, therefore the numerous advantages. You’ll notice that one of the steps above involves elevating the bitumen temperature above 190oC (374oF). This is sometimes considered a disadvantage to the use of RMB, but RMB producers solve this
In the last 10 years, Rubber Pavements Association members have recycled enough tires to make a scrap tire “pipeline” from Cairo to Cape Town, a distance of 8,368 kilometers or 5,230 miles.
ASTM D6114 Defines Rubber-Modified Binder = Asphalt-Rubber is a blend of asphalt cement, reclaimed tire rubber and certain additives, in which the rubber component is at least 15 percent by weight of the total blend and has reacted in the hot asphalt cement sufficiently to cause swelling of the rubber particles.
issue by using an adequately sized hot oil heater on the mixing system that provides sufficient heat to the heat exchanger (generally over 3,000,000 btu/hour) as well as ample heat for the reaction tank. Having sufficient heat to boost cool bitumen temperatures while still having enough heat to reheat a cold tank of RMB is a critical performance criteria. While there are those few disadvantages of RMB to address, South African officials experience the same advantages that other countries have seen with this environmentally friendly practice. Not only does the use of crumb rubber take approximately 4,000 waste tires per mile out of landfills, Rubber Pavement Association members have recycled enough tires in the last 10 years to stretch 5,200 miles (8,368 kilometers) from Purdoe Bay Alaska to Washington D.C. That’s 20.8 million tires. Furthermore, at a cost of $0.18 per pound of GTR, it is price competitive with $300 per ton bitumen, a price the industry has not experienced in many years and not likely to ever see again. Bitumen prices in South Africa today run upwards of $1,000 per ton. Plus you’ve seen in AsphaltPro’s “Around the Globe” reporting that there has been a bitumen shortage for the past 12 months in South Africa, creating huge disruptions in the paving industry. Replacing 20 percent of the require bitumen with GTR is a big supply and cost plus. The conference attendees were especially interested to learn that RMB is both recyclable and can be used in conjunction with Warm Mix Asphalt (WMA). In fact, using RMB with WMA reduces the aerosols typically viewed as a disadvantage of RMB use. I reported on a Summer 2011 overlay project on Interstate 5 in the United States running north from Sacramento. Brain Litts is the QA manager for the George Reed Company, which served as the rubber blender, HMA producer and laydown contractor for the I-5 job. Litts reported 48 June/july 2012
To get ground tire rubber (GTR) blended with asphalt cement (AC), the crew first adds (GTR) into the feed hopper of a mixing system like the one pictured here. On a typical system, load cells monitor the volume by weight of GTR. An auger conveys the GTR from the feed hopper to the mixing can. AC enters a booster heat exchanger where the liquid’s temperature is elevated. The heated AC is then pumped through a metering device and into the mixing container where a high-shear mixer blends the GTR and AC at a high speed. Photo courtesy of CEI Enterprises.
Blended AC and GTR get pumped into a reaction tank where mixing augers and heating coils keep it agitated and hot while it undergoes the agency specified reaction time. When ready, the fully-reacted RMB exits the reaction tank and is piped directly to the HMA plant for the production of rubber hot mix asphalt (RHMA). Photo courtesy of CEI Enterprises.
Using RMB with WMA reduces the aerosols typically viewed as a disadvantage of RMB use. that RMB was used in more than 100,000 tons of RHMA. This included a Type G (gap graded) 12.5-mm (½-inch) RHMA with 7.5 percent RMB and a Type O (open graded) 12.5-mm (½-inch) RHMA surface course with 7.5 percent RMB. The project tested out to meet all applicable CALTRANS parameters. A special note on the project was the 1 ½-hour haul time from the RHMA production plant and Astec Double Barrel to the job site. Other benefits South Africa has enjoyed include a longer overall pavement life, reduced pavement oxidation and maintenance needs,
increased crack, rut and skid resistance, and reduced traffic noise while contractors get to use standard HMA production, paving and compaction practices. As South Africa moves forward with its RMB use, its agencies will save energy, reduce CO2, enjoy safer roadways that last longer, and help sustain the environment through recycling. Richard Champion is the Director of International Sales for CEI Enterprises, Inc., an Astec Company. For more information, contact him at +1 (505) 508-9038 or rchampion@ ceienterprises.com.
Here’s How to Build a Safety Edge by Sandy Lender
A sloped pavement edge leaves a safer driving environment for drowsy or distracted motorists than a vertical pavement edge. Photo courtesy of Allan Barilla of MCL, Regina, Saskatchewan.
y the end of the 2012 calendar year, the Federal Highway Administration (FHWA) expects 40 of the 50 state departments of transportation (DOTs) in the United States to require new pavement construction and resurfacing projects to include a motorist safety feature. Gary Mittleman, CEO of Advant-Edge Paving Equipment, Albany, N.Y., reports that 12 states currently have road construction specs that require contractors to build a 30-degree safety edge as part of asphalt road paving projects. Allan Barilla, general manager of Morsky Construction
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Ltd., Regina, Saskatchewan, pointed out that contractors in his Canadian province haven’t been allowed to leave a vertical edge on the outside shoulder of a highway for years. Presenters including Chris Wagner of FHWA have discussed the topic of pavement edge safety and tools for creating a safe pavement edge at state and national asphalt pavement association meetings for some time now. The tools and techniques are a regular safety topic in this publication. For those unfamiliar with the concept, the sloped pavement edge is designed to assist motorists who
drive off the mainline of the road and make a quick correction to get back on. A vertical pavement edge offers a difficult climb for vehicle tires and often results in the motorist overcorrecting with the wheel, causing the vehicle to veer into oncoming traffic. Wagner has made it clear time and again there is a correlation between drop-off height and danger; there is a correlation between edge shape and safety. If state DOTs specify a wedge or angle to a pavement’s edge, safety increases. With the sloped pavement edge’s popularity fixed, let’s look at how to build it.
Figure provided by AsphaltPro Staff.
Prepare the Surface
Let’s use a pavement preservation technique for our example. If ABC Paving wins the bid to mill and fill a 2-mile stretch of rural highway, the first step is to prepare the surface, as John Ball outlines in “Mill Professionally for Better Project Success” on page 14. When preparing the surface, the crew can’t forget shoulder preparation. The vegetation, rutted mud, gravel, etc., that vertical pavement edges butt up against presents a challenge for a mere overlay. While mowing alongside the road represents one type of roadside maintenance, you want to build something sturdier than a lawn for your shoulder. Brian Balster, Platte, S.D., can attest to that. When his daughter’s
car fell off a vertical pavement edge, good roadside maintenance saved the day. Even a firm shoulder can have ruts, and that’s where the crew begins when the mainline has been milled and swept to perfection. The crew wants to shovel away the vegetation, mulch up the dirt, grade the gravel and compact the loosened material into a solid subbase. That might mean bringing a haul truck out with riprap to level the shoulder with
the pavement, but there’s money under all that vegetation. Balster sells an attachment called the Retriever that’s designed to do all the shoveling-and-mulching work in one pass while “retrieving” the aggregate alongside the road. He offers a simple equation to figure how much money your local agency saves by retrieving what’s already there instead of hauling in more: continued on page 54
thickness x width x formula = yards3/mile x cost/yard = value/mile 1 inch x 36 x 1.3555 = 48.8 x $8.00 = $390.00 ___ x ___ x 1.3555 = ___ x ___ = ___ * Source: Brian Balster, Topps Manufacturing, Platte, S.D.
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Gary Mittleman of Advant-Edge Paving Equipment, Albany, N.Y., explained “The road bed or shoulder base bed must be compacted and extend beyond the edge of the asphalt being applied. Paving a road and/or applying a safety edge over dirt, grass or any non-compacted surface will lead to break-up and failure of the surface being constructed.” The conclusions from the NCDOT report on the Brogden Rd. demonstration project in Johnston County stated “The edge of the pavement separated from the mat at an isolated location where the edge of the pavement was placed over soft soil/vegetation. This would have occurred regardless of the Safety Edge; nevertheless, this underscores the importance of preparing the edge of the pavement.” Photos courtesy of John Bukowski of FHWA.
continued from page 51
Once the appropriate shoulder material is in place, the crew will compact it. OEMs and entrepreneurs have designed tools to make this step safer. Balster’s mulching device that mounts to any 3-point hitch, grader snow wing or grader nose plate switches out for the Retriever Compactor. It features a floating tongue scraper bar and hydraulic vibrator. Another compacting attachment on the market now is the Berm Monster from KTL Fabrication, which you can read about in this month’s Equipment Gallery. Keith Verhoff is the working mechanic who decided he’d seen enough tip-over roller accidents. The result is a device that can attach to your broom so you clean up millings and compact the shoulder at the same time.
Assuming ABC Paving has created a fine milled surface and a sturdy shoulder, we’ll move to the second 54 June/july 2012
step of building the sloped pavement edge, which is paving. As Morsky’s Barilla shared with AsphaltPro readers in April 2011, his crew started with an excellent substructure to lay the mat on. From there, the Morsky crew worked with an attachment to the screed to create a sloped edge of the mat. In the “old days,” they had no way to compact the sloped edge, so it was left uncompacted and with an open texture. Barilla visited with Bill Wright from Carlson Paving Products, Tacoma, Wash., in 2010 and tried out the company’s Vibratory Pavement Edger. While that product wasn’t manufactured specifically for sloping off shoulder edges, it worked in that capacity and functioned as a heated mechanism that provided the same texture as the Morsky crew’s main screed. Of course OEMs and entrepreneurs haven’t left this paving need unmet. Carlson now makes the Superior Safety Edge Bevel, which is a beveled end gate. Tom Travers of
Carlson explained this device uses electric heat and angle of attack to obtain a heated, screeded, compacted and sealed sloped edge. Advant-Edge makes the AdvantEdger™. FHWA has tested that product and Advant-Edge’s Ramp Champ and found them to meet government safety edge paving guidelines, according to Mittleman. “Specifically, they form a 30-degree edge at the shoulder of the road, they automatically follow changes in shoulder elevation and they are not a simple strike-off plate—their trowel surface produces a binding edge. “The Ramp Champ comes with detachable shoes and the operator can change the slope of the tapered edge with it. In cases where the roller is “pushing” the edge out, the operator can flatten out the forming surface to achieve the desired end product.” TransTech Systems, Schenectady, N.Y., worked with FHWA to create the original shoulder wedge maker. Troxler Electronic Labs, Research
With an attachment like the Berm Roller/Tamper, the broom operator can compact the shoulder while getting up the dust and bits left by the cold planer. Photo courtesy of KTL Fabrication.
Triangle Park, N.C., makes the Safe T Slope Edge Smoother, which is one of two that North Carolina DOT used in a demo project on Brogden Rd. in Johnston County last summer. John Ball, proprietor of Top Quality Paving, Manchester, N.H., prefers a device made by a Northeast company called Willow, but said the important factor for paving with any sloped edge shoe is not starving it of mix. “I like the ones that attach to a front-mounted endgate, not the backmounted ones,” Ball said. “If you attach it to the back, look at where your material goes when you slide the endgate out. And keep the end of the augers within 18 inches of the endgate so you can keep the edge device fed, which is what FHWA recommends.” According to FHWA’s Wagner, the devices are all similar in price, hitting the $3,500 to $3,600 range for the hardware, although a quick Internet search will give you varied results. They require minimal additional material when paving because the hot or warm mix is merely being formed and densified by the foot instead of sloughing off unsupported. Each device offers a 25- to 35-degree angle of 5- to 6-inch wide shoulder. That works out great because FHWA currently recommends states require the angle be 30 degrees. 56 June/july 2012
That brings up the issue of creating success. As Advant-Edge’s Mittleman explained, it’s not easy to get a high quality job out of a minimal overlay request. “When resurfacing a road with, say, a 1 ½-inch overlay, it’s difficult to form such a small high quality edge,” Mittleman said. “We suggest that the operator extend the width of the road slightly so that the safety edge will transition from the new surface all the way down to the original shoulder or road bed. This will result in roughly a 4-inch drop-off that the safety edge is covering. It produces a stronger edge and provides significantly greater safety for motorists.” Of course the edge is only safe if it’s strong. These first two steps matter most when the contractor follows through with the third step—compaction.
Compacting the sloped pavement edge has not proved an easy step. Top Quality Paving’s Ball said it’s nearly impossible. He’s seen crews using home-made attachments to rollers or endgates, but they often don’t have the necessary lubrication system to keep the device from picking up material and ruining the edge. Typically, the strikeoff is the only compaction the shoulder sees until
You can see the Troxler device affixed to the extended endgate in this image. Notice that the slope is being created within 18 inches of the end of the paver auger so the head of material is feeding some distance to meet the edge. The crew has flooded the auger so the head of material is not uniform, but they’re working hard to keep the mix feeding to the shoe. Photo courtesy of John Bukowski of FHWA.
To those of us used to seeing shiny objects photographed on gorgeous asphalt mats, the addition of a smart phone to the repertoire should be no surprise. This device isn’t reading temperature or showing VMA; it’s measuring the angle of this sloped edge at 31.2 degrees. Photo courtesy of John Bukowski of FHWA.
the grader blade smoothes the new topsoil on the sloped edge. Morsky’s Barilla said the Carlson rep that met with his team back in the “old days” found fault with that right away. KTL’s Verhoff made the Berm Roller/Tamper with the water system
The crew from Morsky Construction Ltd. used the Vibratory Beveled Edger from Carlson Paving Products to construct a sloped edge and to compact it to keep moisture out. They won a Saskatchewan Heavy Construction Association innovation award for their use of it on their Highway 35 project. Photo courtesy of Allan Barilla of MCL, Regina, Saskatchewan.
When Brian Balster’s daughter drove off a vertical pavement edge, he attributed her ability to walk away from the accident to the good base and lack of vegetation you see in the picture here. FHWA officials hope sloped pavement edges will prevent cars from veering as far as the tracks in this picture show her car did. Preventing off-road collisions and over-correction accidents is the goal. Photo courtesy of Brian Balster, Platte, S.D.
The Retriever from Topps Manufacturing, Platte, S.D., mulches vegetation alongside a rural road and retrieves gravel to the shoulder surface and pavement edge. Photo courtesy of Brian Balster, Platte, S.D. 58 June/july 2012
necessary to avoid material pickup, but he said it’s probably too heavy to put on a breakdown roller. With the overall device weighing about a ton, he worried about the extension’s offset causing undercompaction on the far side of the roller drum or even a mark in the mat on the sloped edge side. Verhoff said it might be a good test for attaching to the finish roller when the mainline mat is more forgiving. No matter what type of device ABC Paving uses, the crew wants to achieve a consistent density along the edge so water doesn’t get into the mat. There’s no longitudinal joint to pinch, but there’s a sloped edge to keep water and freeze-thaw effects from damaging. Tim Murphy of Murphy Pavement Technologies in Chicago pointed out that the contractors out West seal their pavements with a chip seal to protect edges from deterioration, but an extra preservation step might not be in every agency budget as the new safety measures go into place. In the North Carolina demo project, two breakdown rollers were used where the contractor typically only used one. The report stated: “The paver was followed closely by two double steel drum breakdown
rollers, Caterpillar CB 564D and Hypac C778B, operating in echelon. … Both rollers were set for low amplitude with vibration at about 3700 RPM.” The demo’s rolling pattern was as follows: “The two breakdown rollers operating together made three passes, without wandering across the lane, each roller covering one-half of the width of the lane with each pass. Generally, during each of the three passes…the Caterpillar roller overhung the outer edge 2 to 4 inches and the Hypac rolled over the centerline joint 2 to 4 inches. In some instances, the Caterpillar roller would make two passes overhanging the outer edge and the final pass either on the edge or a few inches away from the edge. The pneumatic roller then made up to 15 passes wandering across the lane, with 4 to 5 passes about 18 to 24 inches from the outer edge. The finish roller made two passes, one at the centerline joint and one right on the outer edge.” As readers can see, there’s no mention of direct contact with the sloped edge and NCDOT awaits results from monitoring the project to see how it holds up. In good news, the DOT’s report states that the “densities were higher and the air voids were lower adjacent to the edge in the test sections with the Safety Edge compared to the control section. The confining effect of the devices, which results in additional densification at the edge, is an added benefit of the Safety Edge and may increase the long-term performance of the edge.”
Place additional material The final step for ABC Paving is to come through with new material— such as top soil—to provide shoulder backing for the roadside. Final grading leaves a level shoulder with a strong, safe edge beneath. View the figure on page 51 to see how all of these steps come together to form a safer roadway for the motoring public.
WE CAN SAVE YOU MONEY! Parts · 24-Hour Plant Maintenance · Asphalt · Retrofitting & Used Plant Sales · New · Plant Teardown and Moves 866-981-8965 www.bullisfabrication.com
International Stabilization by John Hood
60 June/july 2012
he new National Route 125 from Toulouse to Auch in France features Flexmix technology, the BOMAG MPH 125 and common sense recycling. The new four-lane route is being built parallel to the old, two-lane road, but still using the existing, natural soil, which is a silty material class A2. That natural soil needs stabilization to make a good road base, which is where BOMAG’s Flexmix comes in. Crews prepare the material from the old road for the new construction with 1 percent lime before loading and transporting it to the new site. There, the MPH 125 homogenates the material to an average depth of 40 cm and average width of 2.6 meters with 4 percent cement and 3 percent water using its fully automatic water injection system. French SETRA specs require the use of soil class A2 in a base course construction to be pulverized to a particle size of 0 to 20 mm. That’s where the BOMAG Flexmix technology comes into play. By pushing a button, the MPH 125 stabilizer operator
can change the graduation of soil to the required size and continue to process without reducing the operating speed. A dozer and grader follow the MPH 125 to level the material and BOMAG’s 26-ton single-drum rollers equipped with Variocontrol technology smooth it all out. The performance output of the MPH 125 is more than 5,000m3 per day. Using BOMAG Telematic, the project manager can monitor costs in real time. Besides tracking, efficiency analysis and other parameters, he can control the fuel consumption of the machine. In a 45-hour week and 65 percent utilization, the average fuel consumption of the MPH 125 was about 50 liters per hour. The operating speed ranged from 12 to 18 meters per minute. The working depth dove down to 60 cm and the width ranged from 2.4 to 2.6 meters. Photos courtesy of BOMAG Americas, Inc., Kewanee, Ill. For more information, contact John Hood, Product Manager, at firstname.lastname@example.org, or visit www.gobomag.com. www.theasphaltpro.com | ASPHALT PRO 61
Russian Show’s Strength is Face to Face by Sandy Lender
opportunities” section of the show directory: dealer/ his May 29 through June 2, a host of construction indistributors; joint ventures; licensing agreements; and, dustry professionals will gather at the Crocus Internaof course, direct sales. Show Director Melissa Magestro tional Exhibition Center in Moscow for CONEXPO Russia commented that “Companies tell us that CONEXPO Ruswhere the construction machinery market place continues sia’s visibility and controlled environment allow them to to grow. Bloomberg reports that the Russian construction concentrate on developing key customer relationships machinery market increased by 144 percent in 2010 and is that lead to sales.” expected to grow by an additional 149 percent by 2013. The focus for exhibitors contacted for this article is on It remains one of the fastest growing markets in the world business, not just immediate sales. Lee shows great interwith GDP growth of 4.4 percent. In May of 2011, Russia’s est in connecting with buyimports jumped up to 44.2 ers who want to expand. percent year over year, acBloomberg reports that the Russian “I am looking for various cording to Bloomberg. buyers in Russia, and CIS Right now, Russia has a construction machinery market regions, and expect posneed for improved infraincreased by 144 percent in 2010 sible cooperation in sales. structure and transport Finally, unlike the globsystems so the governand is expected to grow by an al economy crisis, Russia ment and private corpoadditional 149 percent by 2013. has been developed and rations are ponying up fiis growing quickly in the nancing for major projects. S.O.C. sector, so I rely on the fact that SPECO will defiBy 2015, Bloomberg reports the country will have 14,000 nitely help Russian buyers to contribute themselves to dekilometers of new roads including a toll road from Moscow veloping their own land. Wherever the road construction to St. Petersburg. There’s even a redevelopment project is, there is SPECO.” of the Pulkovo Airport in St. Petersburg in the works that Companies like Transshould cost about 1 bilTech Systems of New York lion Euros. All this activity “Since that show, we have have participated in CONmakes international companies interested in partici- successfully established a Mexican EXPO Russia in past years, and will take a peripheral pating. factory and made it grow as an approach to it now. Jaime Lee, a deputy international company. This year “We did do the show two manager of SPECO Ltd., years ago and found it very South Korea, (stand 8-625) I enthusiastically expect another good,” TransTech CEO Daexplained his asphalt plant miracle in Russia as I am going to vid Apkarian said. “Our lomanufacturing company’s cal distributor felt we were involvement. “I have parparticipate in CONEXPO Russia better off putting the monticipated in many internaies into direct contact.” tional shows,” Lee said. 2012.”—Jaime Lee, SPECO Ltd. Direct contact is what “Among those was CONcompanies like Terex and Wirtgen’s international branchEXPO USA in 2008. I admit that it was a great show that es seek at the show. Asphalt professionals may also recgave us a huge opportunity in marketing and sales. Since ognize exhibitors such as Asphalt Drum Mixers, Inc., that show, we have successfully established a Mexican facHuntertown, Ind., (stand 8-620) which will showcase infortory and made it grow as an international company. This mation about the Milemaker and new EX Series counteryear I enthusiastically expect another miracle in Russia as I flow asphalt plants. Another popular company for our inam going to participate in CONEXPO Russia 2012.” dustry is AggFlow/BedRock Software, LLC, Ft. Mill, S.C., The show organizer, the Association of Equipment Man(stand 8-613) which designs plan simulation and flow analufacturers (AEM), has categorized the means by which exysis software for the aggregate and mining industry. hibitors and attendees can match interests in a “business
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RAP-13455 – 1998 Dillman Duo Drum 500 TPH Plant •RAP 13616 – (2) 200 Ton Astec Silos w/ Weigh Batchers •RAP 13567 – 100 Ton Bituma Silo System •RAP 13481 – (3) 200 Ton Standard Havens Silo System
Stansteel Dryer - 41’ x 10’ 1998 Dillman Mixing Drum 6 Dillman Cold Feeds: 10x15 2 Dillman 300 Ton Silos (1997) w/ Oil Heat Cone, Elec Heat - Gate Dillman Main Drag Slat w/ Elec Heat 36”W x 48” D 2 - 30,000 Gal Dillman “Porta-Stor” AC Tanks 20,000 Gal Vert Waste Oil Tank w/ Pre-Heater Under Burner
•RAP 13548 – Astec 51k CFM Stationary •RAP 12674 – 50k CFM Standard Havens Magnum
HOT OIL HEATERS •RAP 13605 – 1.5mbtu Gentec Serpentine •RAP 13604 – 1.0mbtu Stansteel Helical •RAP 13416 – 1.2mbtu Heatec •RAP 13492 – 1.0mbtu Heatec •RAP 13438 – 1.2mbtu Heatec •RAP 13360 – 2.1mbtu Gencor-HyWay •RAP 13377 – 6.0 Gencor –HyWay •RAP 13264 – 6.0 Fulton Vertical
•RAP 13515 – 150 Ton Bituma Silo and Drag •RAP 13513 – 100 Ton ALmix Silo and Drag
•RAP 13424 – 2002 CMI PTD-300 Port. •RAP 13455 – 1998 Dillman Duo Drum 500 TPH
RAP-13055 CEDARAPIDS E500 CF DRUM
•RAP 13580 – 2000 CMI PTD 400 Port.
•RAP13224 – Gencor 10x15 Rap Bin •RAP 13568 – 9x14 Barber Greene Rap Bin •RAP 13523 – 9x12 Gentec Rap Bin •RAP 13561 – (4) 9x13 Barber Greene Cold Feed Bins RAP 12531 – (4) 9x12 Cold Feed System SCREEN DECKS •RAP 13418 – 2007 4x8 Telsmith Double Deck •RAP 13422 – 1998 4x8 Telsmith Single Deck •RAP 13410 – 1997 4x8 Telsmith Single Deck •RAP 12176 – Telsmith 5x12 Double Deck •RAP 13585 – Deister 6x14 4 Deck Batch Plant Screen
• 114” x 52’ long w/ 126 mbtu burner • Shell thickness close to ½” throughout • Rap collar, trunnion drive, left side discharge
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Diagnose Problems Remotely with Roadtec Telematics
Roadtec’s new remote diagnostics system, Guardian, is designed to find machine or engine problems and report them to the operator via display screen on the milling machine, or report them to a laptop or personal computer. Here a contractor in Snoqualmie Valley, Wash., uses the new RX-600e milling machine from Roadtec with the Guardian software installed. Photo and information courtesy of Roadtec, Chattanooga. 64 June/july 2012
• asphalt contractors • millers, subcontractors • municipalities Finding equipment problems quickly means you get equipment back up and running quickly. You might even prevent work time interruption. To that end, Roadtec has introduced Guardian, a telematics system that lets an operator find just about any machine problem through either the display screen on the milling machine or remotely from a laptop or personal computer. The Guardian system also monitors machine performance and service requirements. Roadtec is first offering Guardian on its new e-Series Tier 4 milling machines including the new RX-600e, which will replace the popular RX500. Eric Baker, marketing manager for Roadtec explained that the RX600e is a result of a customer advisory meeting at Roadtec headquarters. For instance, its water capacity has been increased to 800 gallons. Its fuel economy has been increased and more weight has been added to improve its use of available power. Operating costs should also be lowered due to improved components and serviceability. The telematics system Guardian is what Baker said sets the RX-600e apart from other milling machines. Of the customers who have experienced the Guardian system so far, feedback has been positive. First of all, Guardian can provide machine operating data such as productivity and time-to-service intervals. If there’s a machine or engine fault, the system automatically sends an e-mail to the owner, or to Roadtec, reporting a problem has developed with a specific system on the mill. Kyle Grathwol, the owner of Grathwol Automation and author of the Guardian software, gave an example
of Roadtec receiving an e-mail from a machine in Florida. The e-mail alerted Roadtec that the signal from the left front pulse pickup had been lost. That means the milling machine operator couldn’t trust the speed he was reading of the hydraulic motors driving the tracks. “An engineer at Roadtec logged into that machine in Florida and confirmed the condition,” Grathwol said. The Roadtec engineer called the owner of the milling machine and told the customer the problem, and the customer quickly found a broken wire. “The problem was solved within 30 minutes of the time Roadtec got the email,” Grathwol said. With the Guardian software, Roadtec can connect remotely to any RX600e milling machine in the world and examine all of its systems from a computer in Chattanooga. The connection from the machine to the computer is wireless, with a cell booster to ensure that the machine has a strong signal, according to Kyle Hammon, Roadtec technical marketing coordinator. Engine or machine faults then immediately trigger an e-mail to the machine’s owner. An e-mail will also tell the owner when the machine is due for service. If a fault occurs but no cell phone connection is available, the onboard computer stores fault information until an Internet connection is restored and then sends the e-mail. The Guardian system allows the operator to monitor fuel consumption, engine codes, and other functional systems including alarms, starting circuit, cutter function, water, conveyor speeds, propel functions, load control, hydraulics and more. For example, Grathwol said the system displays electrical circuits by showing inputs on the left, interlocks in the center and outputs on the right. The circuits are basically displayed as a live schematic. If you look at cutter inputs, you might see the left cutter switch on. Then look at the outputs. Actual milliamps of current and desired milliamps are shown on the output side. If the desired output is 3 milliamps but the actual output
shows zero, it means you have an open circuit. “You can tell where your power flow stops and you can tell if it’s an open or shorted circuit,” Grathwol said. “A technician can see the whole schematic of the system.” Steve Concannon, the operations manager at Pavement Recycling Systems, Mira Loma, Calif., tried out the RX-600e with the Guardian system. He said his team was able to get reports on the operating performance of the machine. “It was very beneficial for us to see what the fuel burn was and what the load on the engine was,” Concannon said. “That gave us some indication of the run time versus the standby time. And we were able to evaluate all of that from the office.” Concannon said his company worked with Roadtec to solve a problem with the calibration of the rear track steering. “It was off, and we were able to call in to Chattanooga to change the calibration,” he said. “We got that zeroed out and had it running perfectly in a matter of minutes.” Concannon anticipates the remote diagnostic capability will improve machine uptime. He appreciates the on-board diagnostic capability of the Guardian system. “You don’t necessarily have to use remote diagnostics,” he said. “Just trouble-shooting on the system itself is a big plus. The operator is able to search out the problem himself.” Operators also get e-mails informing them of upcoming maintenance needs. “Our operators carry their smart phones so they can get e-mails about services needed right away,” Concannon said. With Guardian, operators can pull up filter part numbers directly from the screen when they see a filter change is pending. Other features of the RX-600e include efficient milling capacities. Robert Taylor of Talley Construction reported his team used a 7-foot, 2-inch drum to cut about 10 inches deep at about 45 feet per minute. His team also used the new SmoothMill
grade and slope package on the RX600e, which allows the operator to run the grade and slope system from on top. For more information, contact Roadtec at (423) 265-0600 or visit www.roadtec.com. Tell them you saw it in AsphaltPro Magazine.
RX-600e Specs The RX-600e half lane milling machine from Roadtec is a 620-horsepower cold planer available with 4-track assemblies or optional 3-track assemblies. It’s a lighter weight machine that allows contractors to cut up to 13 inches deep with widths of 6 feet, 3 inches or 6 feet, 7 inches or 7 feet, 2 inches. • It features A656 grade 80 steel throughout the frame. • Bolt-on track pads are standard. • It has two independent spray bars to inject water in the cutter housing. The front spray bar is primarily for dust suppression; the rear cools the drum. • It offers a 60-degree conveyor swing. • The engine is a Cummins QSX-15. • It features 4 mode joystick steering control. • The drum diameter, with teeth, is 44 inches. • Travel speed is 3.2 mph. • For the 3-track model, high working speed is 127 fpm; low is 100 fpm. • For the 4-track model, high working speed is 163 fpm; low is 110 fpm. • Shipping weight for the 3-track model is 59,000 pounds; 63,000 for the 4-track model. • Fuel tank is 290 gallons. • Water tank is 800 gallons. • Hydraulic tank is 84 gallons.
www.theasphaltpro.com | ASPHALT PRO 65
equipment gallery ADM’s Recycle Systems Enhance Efficiency
• asphalt producers • asphalt recyclers Asphalt Drum Mixers, Inc., Huntertown, Ind., offers four models of portable and stationary recycle systems to enhance the cost-efficiency of asphalt plants. First, ADM’s recycle bins feature a 15-ton capacity and are continuously welded at the seams. The bins contain angle irons and midsection stiffeners for reinforcement, and their steeply sloped sidewalls prevent material from plugging or bridging, which readers will find important in the RAS measuring article on page xx. A tapered discharge opening leads to the direct-drive belt feeder with a 5-horsepower motor, multi-ply belt, self-cleaning tail pulley and adjustable skirt boards. To transfer RAP from the bin, the recycle system includes a heavy-duty weigh conveyor that features a channel frame and wind shroud protection system for accurate weighing. The conveyor is 2 feet wide and between 45 and 65 feet long. It introduces RAP to the dried aggregate mix after the heating process. Portable units feature a heavy-duty I-beam frame on a gooseneck trailer with a fifth-wheel kingpin hitch, single axle and air brakes. The trailer includes hinged support legs and a hydraulically controlled inclined conveyor. If you need it, ADM offers an optional lump breaker. It features an
The 15-ton capacity bin from ADM features steeply sloped sidewalls to prevent finer, wetter recycle material from plugging or bridging. 66 June/july 2012
adjustable steel breaker plate and replaceable tungsten-tipped teeth. It’s powered by a 30-horsepower, highefficiency motor with an open-mesh covered V-belt drive. Single- and double-deck scalping screens are also available to make sure oversized material doesn’t enter the aggregate mix. Other options include air cannons, grizzlies, bin extensions, adjustable legs with sand shoes, and a skid with bolt-on support legs. For more information, contact Steve Shawd at (260) 637-5729 or sshawd@ admasphaltplants.com, or visit www. admasphaltplants.com. Tell them you saw it in AsphaltPro Magazine.
BOMAG’s MPH122-2 Recycler/Stabilizer Revs Up
• asphalt contractors • subcontractors • site prep Featuring a 482-horsepower turbocharged Deutz V6 engine, the MPH122-2 recycler/stabilizer from BOMAG Americas, Inc., Kewanee, Ill., offers an environmentally friendly solution for various soil stabilization and in-place asphalt recycling tasks. It offers three rotor options, bolt-on tooth holders and an integrated hydrostatic rotor drive. The standard centermounted universal rotor is 91.7 inches wide with 192 cutting teeth and a maximum cutting depth of 19.7 inches. The maximum working speed of the machine is 211 feet per minute. Rotor speeds ranging from 100 to 170 rpm can be selected under load, allowing the MPH122-2 to be adapted to match specific job requirements, whether working as a soil stabilizer or performing various methods of asphalt recycling. The machine uses all-wheel drive. It features a compact design and a combination of articulated and rearwheel steering enhance maneuverability in confined areas. The manufacturer states that a robust center joint provides a smaller turning radius than previous models and ensures constant stability.
The engineers at Bomag minimized the maintenance points on the MPH122-2 Recycler/Stabilizer. The operator’s platform may be lifted to access all components and hydraulic test points are centrally located for simplified trouble-shooting. Bolt-on rotor end segments can be easily replaced, eliminating the need to remove the entire rotor configuration in case of wear. Cutting tooth replacement is simple with a knockin/knock-out design.
In addition, the MPH122-2 has high capacity hydraulic pumps and motors. It’s built with a rigid frame, robust axles and a durable rotor system. An enclosed pressure-ventilated cab with filtered fresh air, heating and air conditioning is available as an option. Other optional equipment includes emulsion and foam bitumen metering systems. For more information, contact BOMAG Americas at (309) 853-3571 or email@example.com or visit www. gobomag.com/recyclers. Tell them you saw it in AsphaltPro Magazine.
Go Deep with Terex RS446C
• asphalt contractors • subcontractors • site prep The RS446C reclaimer/stabilizer from Terex Roadbuilding, Oklahoma City, features a 415-horsepower diesel engine and direct cutter drive with a maximum cutting depth of 20 inches. A two-stage engine drive and threespeed cutter transmission maximizes break-out forces for production rates reaching 155 feet per minute all while saving on fuel costs. The machine incorporates four steerable hydraulic wheel drive motors
equipment gallery at each corner of the machine. In addition to the 155 fpm operating speed, the two-speed transmission offers a 6.4-mph travel speed. Three cutter speeds range from 128 to 209 rpm. Contractors can choose between available 600-gpm water only or water/emulsion additive systems for reclamation and stabilization applications.
The number of frame parts for the Terex RS446C reclaimer/stabilizer has been reduced by 52 percent. A service center is located at the rear of the machine. It features a fold-up ladder and singlepoint access for fueling and hydraulic fluid and central lube system maintenance. There’s unimpeded access to the engine and the service panels are conveniently located in the frame as well.
The housing for the 96-inch wide cutter features a front door that opens twice as far as previous designs, which aids in product grading and sizing when operating in either the up-cut or downcut directions. Heavy duty chains replace rigid turnbuckles to hold the positive of the floating cutter housing at ground level for improved service life. It has a transport weight of 55,000 pounds and an operating weight of 60,000 pounds. The transport height with cab and ROPS is 11 feet 6 inches and width is 10 feet 4 inches. For more information, contact Aron Sweeney at (605) 987-2603 or aron. firstname.lastname@example.org. Tell them you saw it in AsphaltPro Magazine.
Improve Safety by Channelizing Traffic • asphalt contractors • safety directors • DOTs/municipalities
Davidson Traffic Control Products, Tacoma, Wash., recently introduced its high performance channelizer post— the DP 200EFX City Post. This all polyurethane post demonstrates quick rebound when impacted and is designed for high-speed, high-impact locations. The Texas Transportation Institute (TTI) subjected the City Posts to a severe endurance test that showed the posts can survive 50 impacts at 55 mph. The manufacturer states the key features of the post include: • high performance, superior durability • fast replacement, spin-in installation • one-piece construction • no base to become dislodged • polyurethane • 360-degree visibility • Slim profile • All materials made in America For more information, contact Peter Speer at (253) 284-8000 or peter. email@example.com. Tell them you saw it in AsphaltPro Magazine.
Submit New Products for AsphaltPro’s Top 10 Products of 2012—all year long
of 2012 68 June/july 2012
AsphaltPro Magazine is known for its how-to editorial content. Readers spend time in our pages to learn. They also peruse our Equipment Gallery and Here’s How It Works (HHIW) departments, where we showcase the newest iron, equipment and technology for complete product education. More than a regurgitation of OEMs’ product releases, these popular columns give an in-depth look at new equipment, parts and software that make a job easier for asphalt and aggregate industry professionals.
Do you have a new product or a significant upgrade launching in 2012? Make sure your detailed product release, high-resolution image and contact information gets to our editor Sandy Lender at firstname.lastname@example.org. Your product must be included in one of the AsphaltPro’s free editorial Equipment Gallery or HHIW departments in January, February, March, April/May, June/July, August/September, October, November or December 2012 to be considered for the AsphaltPro’s Top 10 Products list that goes to the NAPA 2013 58th Annual Meeting in Scottsdale, Ariz.
here's how it works
Step 3 An MTV delivers mix to the gravity-fed hopper.
Step 1 A 500,000-btu heater keeps tack at the proper temp.
Step 2 An onboard microprocessor controls the rate of flow from the tack tank to the spray bar.
Tack tank holds 2,100 gallons.
Liquid tack continuously circulates through the system.
Spreading augers deliver the mix to the Eagle 10™ screed.
Spray bars extend as needed.
Valves are arranged in sets of three.
Roadtec’s SP-200 Spray Paver™ P
lacing an ultrathin lift often requires a tack coat to make sure you get a good bond to the existing pavement. Then you don’t want a haul truck picking up tack on his tires and leaving inconsistent spots in your mat. Contractors who want to simplify the process can turn to Roadtec for the SP-200 Spray Paver™ that sprays tack seconds before laying mix. Of course, you may need to switch to paving without tack, and there’s no point in switching out the paving train for that when the SP-200 can perform conventional paving as well. Here’s how it works. An operator loads liquid tack into the 2,100-gallon tank before the paving operation begins. A 500,000-btu heater heats a hot oil system, which
70 June/july 2012
keeps the tack in the tank at the proper temperature. The liquid tack continuously circulates through the system, and an onboard microprocessor controls the rate of flow to the spray bar, which is directly in front of the paving augers. The valves on the spray bar are arranged in sets of three so the paver operator can drive forward at higher speeds with plenty of spray capacity. A pan captures excess tack, and the material is pumped back to the heated tank. The spray bars extend as needed with the screed and each nozzle can be manually shut off for partial passes. For the final steps, and for conventional paving at any time, a material transfer vehicle (MTV) delivers mix directly to the SP-200 gravity-fed hopper,
which has a capacity of 11 tons. The 14by ¾-inch spreading augers deliver the mix to the Eagle 10™ hydraulically extendable, vibrating screed. For more information, contact Roadtec at (800) 272-7100 or (423) 265-0600 or visit www.roadtec.com. Tell them you saw it in AsphaltPro Magazine.
Show us How it Works If you’re an equipment manufacturer with a complex product, let us help you explain its inner workings to the readers of AsphaltPro magazine. There’s no charge for this editorial department, but our staff reserves the right to decide what equipment fits the parameters of a HHIW features. Contact our editor at email@example.com.
here's how it works
Maxam’s Perma Stor™ Silo System P
roducers who wish to eliminate oxidation of stored mix, prevent blue smoke escape, and reduce maintenance and utility costs have the option of Maxam’s newly launched Perma Stor™ Silo System. This bintop system can be retrofitted to other manufacturer’s silos by eliminating the conveyors and batchers for multiple silos, using only 12 horsepower to run up to 10-silo batching. Here’s how the four-part system works. First, the prepared mix travels up the main drag slat conveyor as it normally would. There it drops into a stationary batcher that is affixed to the discharge end of the conveyor. The stationary batcher’s limit switch opens its gate to empty approximately 5 tons of mix into the batcher of the Bintop Transporter™ (part one). The Transporter then shuttles between silos on rails at about half normal walking speed to reach the desired silo, allowing up to
72 June/july 2012
750 tons per hour production. By adding a crossover gantry, the system can accommodate up to 10 silos over two truck scales or 15 silos over three scales. The Transporter brings its batcher to rest above the selected silo and its blue-smoke skirt closes down against the bin top to prevent fume escape. It then drops the mix into the silo before the Troo Loc™ Bintop Seal (part four) closes off the silo and the Transporter returns to the stationary batcher for another load. At the end of the shift, the plant operator signals the Oxi-Free™ Purge System (part two) to purge oxygen from the silo. First, the Troo Loc bintop seal raises on top of the silo. Next, the OxiFree system fills the Aqua-Seal™ Bin Gate (part three). It then injects steam into the cone of the silo, causing steam to rise through the mix and purge out all the oxygen.
Once the oxygen sensor at the top of the silo measures zero oxygen, it sends a signal to the Oxi-Free control to stop the steam injection and lowers the Troo Loc seal for air tight storage. Only a few quarts of water are required for the total process on a 300-ton silo and because steam will not support combustion or oxidation, no aging of the mix takes place in the silo during storage. At the beginning of the next shift, the plant operator drains the AquaSeal gate. The wheel loader or truck receives a small plug of mix from the base of the silo for the RAP pile and truck loading is ready to begin. For more information, contact Andy Welch at awelch@maxamequipment. com or Mike Hawkins at mhawkins@ maxamequipment.com or call 800-2926070. Tell them you saw it in AsphaltPro Magazine.
resource directory ACE Group...................................49 Contact: Carl McKenzie Tel: 888-878-0898 firstname.lastname@example.org www.asphaltace.com
CEI..................................................4 Contact: Andy Guth Tel: 800-545-4034 email@example.com www.ceienterprises.com
Heatec, Inc.........Inside Front Cover Contact: Sharlene Burney Tel: 800-235-5200 firstname.lastname@example.org www.heatec.com
Asphalt Drum Mixers....... 24, 52-53 Contact: Steve Shawd or Jeff Dunne Tel: 260-637-5729 email@example.com www.admasphaltplants.com
Clarence Richard Co.....................26 Contact: Clarence Richard Tel: 952-939-6000 Carrie@clarencerichard.com www.clarencerichard.com
Herman Grant Co., Inc..........……31 Contact: Paula Shuford Tel: 800-472-6826 firstname.lastname@example.org www.hermangrant.com
Astec, Inc.................... 29, 40-41, 55 Contact: Tom Baugh Tel: 423-867-4210 email@example.com www.astecinc.com
Dillman Equipment................ 18-19 Tel: 608-326-4820 www.dillmanequipment.com
Kenco Engineering................... …27 Contact: Brad Brad@kencoengineering.com Tel: 800-363-9856 www.kencoengineering.com
B & S Light Industries...................28 Contact: Mike Young Tel: 918-342-1181 Sales@bslight.com www.bslight.com Bomag Industries................... 34-35 Tel: 800-782-6624 or 309-853-3571 firstname.lastname@example.org www.bomag.com Bullis Fabrication..........................59 Contact: Greg Bullis Tel: 866-981-8965 email@example.com www.bullisfabrication.com
E.D. Etnyre...................................25 Contact: firstname.lastname@example.org Tel: 800-995-2116 www.etnyre.com EZ Street................................43, 45 Tel: 800-734-1476 Info@ezstreet-miami.com www.ezstreetasphalt.com
KPI-JCI…......................................69 Contact: Lisa Carson Tel: 605-668-2425 email@example.com www.kpijci.com
Fast-Measure................................73 Tel: 888-876-6050 www.Fast-measure.com
Maxam Equipment..................insert Contact: Lonnie Greene Tel: 800-292-6070 firstname.lastname@example.org www.maxamequipment.com
Gencor Industries.........................11 Contact: Dennis Hunt Dhunt@gencor.com www.gencor.com
Meadwestvaco............................ 17 Tel: 800-458-4034 www.evotherm.com www.mvw.com
NAPA.............................………….57 21 Century Asphalt Conference www.asphaltpavement.org NAPA…..........................…………32 Annual Meeting www.asphaltpavement.org
Stansteel.......................................37 Contact: Dawn Kochert Tel: 800-826-0223 email@example.com www.hotmixparts.com Tarmac International, Inc..............13
Reliable Asphalt Products...................Back Cover, 63 Contact: Charles Grote Tel: 502-647-1782 firstname.lastname@example.org www.reliableasphalt.com
Contact: Ron Heap
Roadtec......................................7, 9 Contact: Sales Tel: 423-265-0600 Sales@roadtec.com www.roadtec.com
Contact: John Ball
Rotochopper, Inc.......................... Inside Back Cover Tel: 320-548-3586 Info@rotochopper.com www.rotochopper.com Stansteel AsphaltPlant Products..................33 Contact: Dave Payne Tel: 800-826-0223 email@example.com www.stansteel.com
Tel 816-220-0700 firstname.lastname@example.org www.tarmacinc.com Top Quality Paving.......................73 Tel 603-624-8300 Tqpaving@yahoo.com www.tqpaving Wirtgen America..........................47 Tel: 615-501-0600 Info@wirtgenamerica.com www.wirtgenamerica.com WRT Equipment...........................21 Contact: Dean Taylor Tel: 800-667-2025 or 306-244-0423 email@example.com www.wrtequipment.com
AsphaltPro’s Resource Directory is designed for you to have quick access to the manufacturers that can get you the information you need to run your business efficiently. Please support the advertisers that support this magazine and tell them you saw them in AsphaltPro magazine.
www.theasphaltpro.com | ASPHALT PRO 73
the last cut
It’s As Simple As That by Sandy Lender
all it frugal spending, pinching pennies, fiscal conservatism or whatever you like; it makes sense to control where a business can cut expenses. As expected, diesel and AC prices represent large expenses again this spring. You can’t knock those out, but industry experts have offered—and often in the pages of this magazine—ways to minimize their impact through optimized equipment tuning and recycled material use, etc. Something of interest lately is the idea that at least fuel prices will remain “reasonable” in the United States this summer and fall because this is an election year. And it’s as simple as that. As mind-boggling as it sounds, pundits leave the conversation with the ghostly implication that one person in Washington, or his Campaign Manager Jim Messina, can influence the price of a gallon of diesel fuel to the extent that its price will remain below US$4 through November, unless you’re in California where the price has been bouncing above the $4 mark for a while. Wouldn’t it be in the nation’s best interest to keep Messina in place indefinitely if he can wield that kind of power? Smack in the middle of the country—Missouri—the price of ultra low sulfur diesel (ULSD) has gone from $2.95 a gallon Jan. 1 to $3.39 a gallon May 1, according to MoDOT. The only time it’s been higher there in recent memory is May 1, 2011, when it was $3.40 a gallon. Everyone in the construction industry knows a host of factors go into the fluctuations we’ll see in both gasoline and diesel prices. While liquid AC prices have only seen pleasant dips in Colorado so far this year—as compared to prices in the Southeast, Northeast and further West—crude prices have been lower across the board than they were early in the year. That decrease has helped feed the decrease in gasoline prices. According to the Energy Information Administration, producers on the West Coast can blame high prices on “refinery issues.” Specifically, the West Coast has experienced abnormally low refinery runs since February. That tightened the local gasoline markets. Refineries began their usual seasonal maintenance in January and February. Then BP had a fire in late February in its Cherry Point refinery in Washington. Unplanned outages elsewhere made for a perfect storm of low supply, high demand and high prices. In good news, the Cherry Point refinery is due to come back online and all that planned refinery maintenance is done. This means prices are ready to even back out in the West. Can we thank Messina? It’s actually not as simple as that.
74 June/july 2012
Liquid Asphalt Cement Prices—average per ton Company, State
NuStar Energy, Ga.
NuStar Energy, N.C.
NuStar Energy, Va.
Assoc’d Asphalt Inman, N.C.
Assoc’d Asphalt Inman, S.C.
Assoc’d Asphalt Inman, Va.
Marathon Petroleum, Tenn.
Marathon Petroleum, N.C.
Valero Petroleum, N.C.
Data for Southeast region, Source: ncdot.org; Data for Massachusetts, Source: mass.gov; Data for California, Source: dot.ca.gov; Data for Missouri, Source: modot.mo.gov; Data for Colorado, Source: CDOT and Cenovus
Crude Oil Activity (U.S. Crude) futures spot data
344.9 m bbl
345.7 m bbl
347.5 m bbl
346.3 m bbl
353.4 m bbl
Diesel Fuel Retail Price (dollars per gallon) Feb 27
362.4 m bbl
365.2 m bbl
369.0 m bbl
373.0 m bbl
375.9 m bbl
Sources: Energy Information Administration
“LET FREEDOM RING” INDEPENDENCE DAY 2012
THE INDUSTRY LEADER IN
USED EQUIPMENT 866.647.1782 • www.ReliableAsphalt.com
Published on Jun 1, 2012
In the June / July 2012 issue of Asphalt Pro: Haskell Lemon Places Kraton's HiMa; AR at NCAT, Africa; Build the Safety Edge; Add RAS with A...