When it Rains, it Drains!
Reduces Runoff Cleans Storm Water Replenishes Aquifers Conserves Water Protects Streams ADA Friendly
www.tri-north.com Green Building Leader
What is Pervious Concrete? Pervious concrete is a special type of concrete with a high porosity which allows water from precipitation and other sources to pass through it, thereby reducing the runoff from a site and recharging ground water levels. The high porosity is attained by a highly interconnected void content. Typically, pervious concrete has little to no fine aggregate particles while preserving the interconnectivity of the voids. Pervious concrete is traditionally used in parking areas, areas with light traffic, pedestrian walkways, and greenhouses. It is an important application for sustainable construction.
This 14’ x 60’ pervious pavement over a 6’ recharge bed was engineered and installed by Tri-North Builders in conjunction with a NRMCA contractor certification class sponsored by the University of Wisconsin. This photo shows the water sheathing off the asphalt and draining into the highlighted pervious concrete section.
Construction of a typical recharge bed.
Applications of Pervious Concrete
A Bunyan Roller Screed used to strike off and consolidate pervious concrete. Curing takes place immediately after placing.
• Low-volume pavements • Residential roads, alleys, and driveways • Sidewalks and pathways • Parking lots • Low water crossings • Patios • Artificial reefs • Slope stabilization • Tree grates in sidewalks • Foundations/floors for greenhouses, fish hatcheries, aquatic amusement centers, and zoos • Hydraulic structures • Swimming pool decks • Pavement edge drains • Groins and seawalls • Noise barriers
Benefits of Pervious Concrete • Drastically reduces stormwater run off from properly designed parking areas. • Stops more than 99% of contaminates that typically flush into streams when used with a bio-swale. • Replaces or reduces the need for typical parking lot storm sewer systems. • Can be designed to eliminate detention basins typically designed into parking lots. This means flatter and safer parking lots. • Can be designed with enough storage capacity to replace open detention basins. This leaves more room for parking and commercial space which is a better return on investment. • Reduces construction time. Excavators can grade the building pad and the parking area at one time. Base rock can be installed early with no need to come back to excavate for storm sewers, detention basins, or catch basins. • Reduce government fees. Some local governments charge fees based on impervious surfaces, but these fees can be avoided or reduced by using pervious. Some governments are considering an annual tax based on impervious surfaces. If that happens, pervious parking lots and driveways will become an even greater value.
A Bunyan Roller Jointer is used so there is no need for sawing joints at a later time.
A finished joint from the Bunyan Roller Jointer.
Tri-North Builders is a full-service general contractor. We specialize in commercial, retail, healthcare, and hospitality construction throughout 50 states. We are headquartered in Madison, Wisconsin, with additional offices in the Milwaukee and Dallas areas. Tri-North Builders is passionate about green construction, staffing several LEED速 Accredited Professionals. Our commitment to sustainability is reinforced by our new corporate headquarters. This building is a Gold LEED速 certified project. Pervious concrete is helping us achieve LEED速 points through the following means: SS7.1 Landscape & Interior Design to Reduce Heat Island, Non Roof ID
Innovation in Design
Because of the use of pervious concrete, Tri-North Builders qualified for reduced storm water run-off tax credit.
Pervious concrete captures rainwater and stores it in a recharge bed until it can percolate back into the soil, replenishing the aquifer. Note the amount of water running off the lot adjacent to Tri-North Builders Corporate - day this picture was taken we received .68 inches of rain.
This photo depicts a portion of the 8,200 sq. ft. of previous concrete at our new corporate headquarters.
Tom Geary Concrete Division Manager
608.712.0853 mobile firstname.lastname@example.org
For more information about pervious concrete, please contact Tom Geary, the Concrete Division Manager for Tri-North Builders. Tom’s primary responsibilities are planning, organizing, scheduling, and executing all flatwork concrete operations. Tom’s professional affiliations include the following: •
International Brotherhood of Carpenters and Joiners Local #314
Operative Plasterers’ and Cement Masons’ Local #599
• ACI Concrete Field Testing Technician Grade 1 •
ACI Concrete Flatwork Finisher and Technician
N.R.M.C.A. Certified Pervious Concrete Technician
Instructor for the Wisconsin Cement Masons Apprenticeship Program
Board Member for the Madison Plasterers and Cement Masons J.A.C.
PO Box 259568 | Madison, WI 53725-9568 2625 Research Park Drive | Fitchburg, WI 53711-4908 608.271.8717 phone | 608.271.3354 fax www.tri-north.com M a d i s o n TNB-1009 © 7/09
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