Asphaltopics Fall 2023

FALL 2023 | VOL36 | NO3

MIX DESIGN SYSTEMS Marshall and Superpave ASPHALT REJUVENATON unlocking RAP’s potential SUSTAINABILITY role of ESG

Publications Mail Agreement #40011181 ADVERTISING SALES REPRESENTATIVE Patricia Abbas | 416.438.7609 | pabbas8@gmail.com The official publication of the Ontario Asphalt Pavement Council, ASPHALTopics is published three times a year.

EDITOR Lara Henry | larahenry@sympatico.ca

Ontario Asphalt Pavement Council 365 Brunel Road, Mississauga, ON, L4Z 1Z5

DESIGN & EDITORIAL LAYOUT pdplante.com inc. | pdominiqueplante@gmail.com

Tel: (905) 507-1107 • Fax: (905) 890-8122 Email: info@onasphalt.org Website: www.onasphalt.org

COVER PHOTO Highway 141 at Skeleton Bay west of Bent River. (Fowler) © 2023 All Rights Reserved.

TABLE OF CONTENTS 05 Chair’s Corner 07 Operations Corner 09 MarCom Matters 10 Marshall and Superpave mix design systems 16 Environmental stewardship and Trillium 18 Unlocking RAP’s potential 24 Sustainability and ESG 27 Asphalt Technical Symposium 29 Members’ Golf Tournament 30 Cure time for asphalt 33 Unsung Heroes 35 Technically Speaking 38 Environmental Essentials 40 Industry News 42 The Last Word FA L L 20 23 3

CHAIR’s CORNER Peter Hamstra Chair

A busy year with more to come Where did the summer go? As the fall season is in full swing, paving crews around the province are working hard to finish up their projects before the weather turns and winter shutdown hits again. The production and laydown aspect of our industry is very seasonal in Ontario. However, the maintenance, planning and management side of our industry goes strong all year round. It is the same with the work of OAPC. There is no downtime as the staff and the committee volunteers are busy all year round delivering on the priorities of OAPC with a full slate of educational, advocacy and networking opportunities.

We know that engaging our municipal partners is critically important as they comprise the largest group of asphalt purchasers in the province. Promoting the responsible use of RAP (reclaimed asphalt pavement) and standardizing specifications are two of the many topics we plan to continue discussions on. We are exploring how a greater participation at the annual Good Roads conference in April and the annual Association of Municipalities of Ontario conference in August could bring better collaboration to our relationship with the municipalities.

I want to thank ORBA’s outgoing CEO, Michael McSweeney, for his work over the past year to restructure and reposition both ORBA and OAPC for a stronger, more impactful future. The new staff leadership team at OAPC/ORBA announced earlier this summer, led by our incoming CEO, Walid Abou-Hamde, will be focussed on delivering the best possible value to our members and stakeholders. I am extremely confident that we have the right team in place to lead us in delivering on our commitments.

The upcoming Fall Asphalt Seminar is one of our most popular events of the year. This event, which will take place on November 30, brings together people from all corners of the province and beyond to learn and collaborate about hot topics and emerging technologies related to the asphalt industry. Keeping ahead of the changes in the industry as well as promoting best practices is one of the most important things we do as a council. There is always a full agenda of topics that are sure to grab the interest of all attendees. I hope you will consider attending.

The recently renewed focus on the OAPC and ORBA strategic priorities will bring added clarity to the work we do going forward. We are constantly evaluating the successful things and less successful things we do to ensure we are spending our time and energy in the most impactful ways and places.

The delivery and timing of the events we hold are being reconsidered as part of this evaluation process. Feedback from our membership is also a very important part of this so if you have input or suggestions, please let us know.

This year as chair of OAPC has been an exceptionally educational and rewarding experience for me. There are so many passionate and dedicated people working in our industry.

I have been fortunate to connect with many of them through the various events and meetings that have taken place this year.

I especially want to thank the Board of Directors of OAPC for their wisdom and support. It’s truly the people that make it a remarkable organization.

Stay safe!

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information pertaining to the National Research Council Canada (NRC) funding and support for the construction industry to meet Canada’s 2030 and 2050 greenhouse gas (GHG) reduction targets.

OPERATIONS CORNER Doubra C. Ambaiowei Director, Technical Services

Progress is good Who would believe the end of the year would come so quickly, with yet another Fall Asphalt Seminar (FAS) in view? Indeed, time flies!

This year, we have emphasised a renewed action plan in addressing our strategic and operational priorities of: Quality; Sustainability; Codes, Standards and Specification; Research and Education; and Advocacy and Stakeholder Relations. To this end, I’m pleased to report that PROGRESS IS GOOD! Robust discussions and dialogue were had with several interest groups in our continuing quest to deliver quality asphalt pavements and solutions in Ontario.

New partnerships have been forged and existing partnerships are being renewed to advance and promote asphalt strategies, initiatives and processes that will benefit the environment, improve society, and provide an overall economic benefit.

The 2024 ORBA Road Building Academy will feature repeat courses such as Fundamentals of Asphalt Plant Operations, Practical Solutions in Hot Mix Technology 2.0, and Practical Solutions in Managing Excess Soil.

We have further added two additional courses — Data Analytics and DecisionMaking in Civil Engineering Applications, and Flexible Pavement Design. We encourage you to check them out and register. As a reminder, employers can take advantage of the Canada Ontario Job Grant (COJA) which significantly subsidizes the cost of these courses.

We are intentional in our efforts to cover the hard-hitting issues and maintain our lead as the voice of asphalt pavements across Ontario by continuing to advocate and improve stakeholder relationships.

While we have achieved so much this year, there is still much more we can do together in sustaining the vision and mission to promote quality and sustainable asphalt products and paving techniques in Ontario. We continue to count on your enthusiasm, engagement, committment and meaningful partnerships for the collective good of the asphalt paving and road building industry.

Our motivation to support industry-focused research and provide adequate educational resources to members resulted in key accomplishments through active collaborations with the leadership and members of the Ontario Asphalt Expert Task Group (OAETG). The results of these efforts were presented at this year’s Asphalt Technical Symposium (ATS), the 2023 Transportation Association of Canada (TAC), and the Canadian Technical Asphalt Association (CTAA) conferences.

Staying true to our tradition, this fall edition of ASPHALTopics features articles from key Fall Asphalt Seminar speakers and highlights some important OAPC accomplishments. With the theme of Advancing with the Times: People and Processes, this year’s FAS promises to shed light on the evolving landscape of asphalt innovations and technology. Join us for an exciting day of education and, of course, opportunities for networking and recognition.

Through ORBA’s educational webinar series, members had the the opportunity to gain unique insights and perspectives into developments in Ontario’s transportation infrastructure sector. Key successes this year were aimed at simplifying the understanding and implementation of MTO’s cross-slope specification amendments; understanding optimal application of 3D milling and paving technologies; and

As always, I look forward to hearing from you pertaining to all things asphalt.

Do enjoy the fall activities, and I wish you an enjoyable yuletide. See you again in the new year!

We have continued to proactively participate in the development, review, and harmonization of achievable specifications industry-wide with an emphasis on encouraging a switch from the Marshal mix design method to the Superpave mix design method. We have also sought industry’s input in navigating the issues and solutions to attracting and retaining talent for the asphalt paving and road building industry.

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MARCOM MATTERS Guru Missar Director, Marketing & Communications

Adaptive communication In an industry as dynamic and ever-evolving as the Ontario asphalt sector, staying ahead of the latest trends, policies, and innovations is not a luxury—it’s a necessity.

For OAPC, this involves ensuring that every member is on the same page, connected, and engaged. The answer to how to tackle this formidable challenge? Adopting the philosophy of adaptive communication.

INFORMED, ENGAGED, AND RETAINED MEMBERS The foundation of adaptive communication rests upon the understanding that effective communication isn’t about bombarding members with information. Instead, it’s about ensuring content relevancy, engagement, and fostering a sense of belonging.

Traditionally, many councils and associations have approached information as a oneway flow, going only from the top down, with little room for interaction. However, this perspective is not only outdated but also counterproductive.

At the heart of this philosophy lies the principle that information isn’t just about broadcasting—it’s about engagement. But what does ‘engagement’ truly mean in this context?

1. Relevancy and Timeliness: Before members can engage with information, it has to be relevant to their interests and timely. For instance, in the asphalt industry, updates on regulatory changes, technological advancements, or market trends need to be communicated swiftly. If members feel the council is always at the forefront, offering them the latest insights, they are more likely to trust and engage with its content.

2. Interactivity: Engagement is fostered when members can interact with the information. This might mean offering webinars where members can ask questions in real time, forums where they can discuss articles and reports with their peers, or workshops where they can get hands-on experience with new technologies or methodologies.

3. Personalization: One-size-fits-all is no longer viable. The more tailored the information is to a member’s specific needs or interests, the higher the engagement.

With today’s technology, it’s feasible to offer personalized content streams or

specialized newsletters, ensuring that members receive the information most pertinent to them.

4. Empowerment: Information should not just be a passive reception. It should empower members to take action, make informed decisions, and contribute back to the council. When a member reads about a new technology, they shouldn’t just understand it theoretically; they should feel equipped to implement it, discuss it, and even offer insights to improve it further.

NAVIGATING THE EVOLVING MARKETING LANDSCAPE The modes of communication have dramatically changed in the past decade.

While newsletters and print materials have their place, digital channels such as webinars, social media updates, and podcasts offer more immediacy and reach. The adaptive communication model recognizes this shift and emphasizes the need to remain agile.

It’s about using analytical tools to discern which communication channels are most effective for our demographic. Do our members prefer bite-sized updates on Twitter or in-depth articles on LinkedIn? Are they more likely to engage with a YouTube tutorial or a podcast interview?

By understanding these preferences, OAPC can craft targeted, effective communication strategies that resonate.

TWO-WAY COMMUNICATION: FOSTERING A COLLABORATIVE ENVIRONMENT Merely broadcasting information is a relic of the past. The modern council understands the value of listening as much as speaking. Every question posed, feedback given, or concern raised by a member provides invaluable insights.

The collaborative nature of this magazine stands as a testament to adaptive communication in action. With content curated and brought to you by the dedicated OAPC committees and staff, it showcases our commitment to collaboration and engagement. And our door is always open. We openly encourage members to contribute, share their expertise, and become an integral part of this evolving narrative.

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THE FUTURE OF QUALITY ASPHALT IN ONTARIO A review of Marshall and Superpave mix design systems 10 OA P C | ASP H A LTOP IC S

High quality HMA is the crucial support material that ensures the safe and smooth transportation of individuals and commodities throughout Ontario. The adequacy and competency of the HMA used in road construction is vital, influencing both the durability and functionality of our roadways.

Exploring the evolution and potential advancements in hot mix asphalt technology (HMA) in Ontario requires a deep dive into the province’s transportation infrastructure.

This article takes a close look at the two most prominent mix design systems in Ontario — Marshall and Superpave — while offering insights into current methodologies and their comparison. We will journey along the path to high-performance asphalt mixes using a balanced mix design approach for Ontario. We will also critically examine these methodologies and weigh their merits and challenges, all while envisioning future innovations in asphalt technology.

©Shutterstock

by Dr. Salman Bhutta

THE MARSHALL METHOD OF MIX DESIGN – ONTARIO HISTORICAL PERSPECTIVE The Marshall mix design system, originating in the 1930s, was developed

by Bruce Marshall of the U.S. Army Corps of Engineers and has been solidly anchored in the prevalent asphalt mix design methods in Ontario for many decades. Though it built upon the Hubbard-Field approach, the Marshall system introduced distinctive variations in compaction methodologies, characterized notably by the application of a uniform impact hammer load over the asphalt mix contained in a 100 mm diameter metallic mold. This system used the calculation of air voids and Voids Filled with Asphalt (VFA) as a principal criterion dictating mix designs.

In a differing stance, Dr. Norman McLeod championed the inclusion of Voids in Mineral Aggregate (VMA) by initially recommending a uniform VMA level and then transitioning to an aggregate size-based sliding scale in the 1950s. Following rigorous debate, the Asphalt Institute in the U.S. incorporated VMA into its MS-2 Asphalt Mix Design Methods manual as a mix design criterion in 1962, subsequently influencing AASHTO and ASTM standards. ›› FA L L 20 23 11

The Marshall mix design system, recognized for its extensive and effective history in Ontario and beyond, provides a familiar terrain for engineers and contractors alike in the domain of asphalt mix design. While it offers numerous merits, the method may fall short in holistically addressing important durability concerns such as cracking and fatigue. In the 1990s, this gap in a more comprehensive performance solution drove the adoption of the Superpave mix design in the U.S. The Superpave design promised to navigate these challenges by also introducing a novel method of selecting asphalt binder. The Marshall method, with its inclusion of both VMA and VFA, held sway in Ontario until the early 2000s when the Superpave method emerged, signaling a significant shift in asphalt mix design methodologies.

THE EARLY YEARS OF SUPERPAVE IN ONTARIO Superpave, standing for Superior Performing Asphalt Pavements, emerged from the Strategic Highway Research Program which was inaugurated in the United States in 1987. Originally envisioned as a five-year research endeavour, its objective was to establish a logical approach to asphalt mix design with an aim to extend pavement longevity. Moreover, the Superpave system pioneered a unique performance grading (PG) system for asphalt binders, integrating a grading methodology based on accommodating climatic temperature variables with statistical reliability as its backbone. This innovative approach aimed to reconcile mix design with specific regional and seasonal temperature fluctuations to enhance pavement durability and performance.

The Superpave mix design method operates on the principle of simulating the compaction energy and mechanism experienced in the field, replicating them in a laboratory environment to develop a compaction procedure that emulates real-world HMA placement and compaction. The method involves gyrating the asphalt mix in a 150 mm diameter mold using a plate that simulates roller compaction as experienced in actual field conditions. The mix design methodology underwent numerous iterations before ultimately being adopted by the Ontario Ministry of Transportation in early 2005, showcasing a commitment to refining and optimizing asphalt pavement performance through a well-vetted design process.

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Superpave Gyratory Compactor Mechanical Marshall Hammer. (Courtesy Humboldt Testing Equipment and Pine Instruments) ASPHALTopics served as a pivotal platform, offering industry updates and amplifying issues or challenges encountered in the field. A noteworthy article from its summer 2003 issue, “Ontario Superpave Update,” featured the inaugural 1997 Ontario site of Highway 17 at Petawawa. This success forged a path for the deployment of a staggering 700,000 tonnes of Superpave mix in 2002, subsequently swelling to 1 million tonnes in 2003. The implementation experience to that juncture was largely positive as chronicled in reports from major cities like Toronto, Ottawa, and Kingston.

An early Superpave project in June 2003 in Kingston, Ontario was featured in the summer 2003 issue of ASPHALTopics.

Ottawa’s experience was particularly instructive, shedding light on challenges related to converting conventional municipal mixes such as HL-3 and HL-8 to the Superpave method. The encounters in Ottawa spotlighted the rapid densification at the 50-gyration level, precipitated by the fineness and high percentage of natural sand in those mixes. Gradation was underscored as a critical success factor, pinpointing a need for adjustments particularly in moderating the quantity of natural sand. Furthermore, significant emphasis was placed on a performance test to align with mix volumetric requirements, heralding strides toward the comprehensive implementation of a province-wide standard by 2005.

Superpave prioritizes a tailored approach, ensuring that the formulated asphalt mix is directly correlated with the anticipated vehicular load, promoting an optimized and enduring pavement performance across varied traffic conditions (reference OPSS. MUNI 1151 Table 1 below).

TRAFFIC 20-YEAR DESIGN CATEGORY ESALs1

1

TYPICAL APPLICATION

A

Less than 0.3 million

Low volume roads, parking lots, driveways, and residential roads.

B

0.3 to 3 million

Minor collector roads.

C

3 to 10 million

Major collector and minor arterial roads.

D

10 to 30 million

Major arterial roads and transit routes.

E

Greater than 30 million

Freeways, major arterial roads with heavy truck traffic, and special applications such as truck and bus climbing lanes or stopping areas.

quivalent Single Axle Load (ESAL) for the projected traffic level expected in the design lane over a 20-year period, regardless of the actual E design life of the pavement.

The Superpave mixes in Ontario are very closely related to the conventional Mashall mixes as detailed in the table from OPSS. MUNI 1151-A Commentary below.

HOT MIX ASPHALT TYPE

TYPICAL HOT MIX USE AND PROPERTIES

Superpave 4.75

Fine, surface, and levelling mixes similar to the traditional sand mixes for miscellaneous applications.

Superpave 9.5

Fine, surface, padding, and levelling mixes for Traffic Category A and B roads and driveways.

Superpave 12.5

Surface mix for Traffic Category B and C roads. Superpave 12.5 is similar to the traditional HL 3, HL 3 Fine, and HL 4 mixes according to OPSS 1150. The HL3-HS and HDBC/HL8-HS mixes fall under the Traffic Category D and E under this mix type.

Superpave 12.5 FC1

Surface mix for use on Traffic Category C roads that provides superior rutting resistance and skid resistance through aggregate selection. Superpave 12.5 FC1 is similar to the traditional HL 1 mix according to OPSS 1150.

Superpave 12.5 FC2

Surface mix for use on Traffic Category D and E roads that provides superior rutting resistance and skid resistance through aggregate selection. Superpave 12.5 FC2 is similar to the traditional DFC mix according to OPSS 1150.

Superpave 19.0

Binder course mix for Traffic Category A, B, C, D, and E roads. Superpave 19.0 is similar to the traditional HL 4, HL 8, and HDBC mixes according to OPSS 1150.

Superpave 25.0 and 37.5

Large stone binder course mixes for use when thicker binder lifts are required.

SMA 9.5 and 12.5

Gap-graded premium surface course mix with high frictional resistance, enhanced rutting resistance, water spray reduction, and potential noise reduction for Traffic Category D and E roads. 100% crushed aggregates from the DSM are used for both fine and coarse fraction.

SMA 19.0

Gap-graded premium binder course mix with enhanced rutting resistance for Traffic Category D and E roads. 100% crushed aggregates are used for both fine and coarse fraction. ›› FA L L 20 23 13

Appendix 1003-G of OPSS.MUNI 1003 introduces further mix aggregate requirements under consensus properties that pertain to all the mixes presented in the previous table. It is important to acknowledge that the requirements and aggregate properties applicable to Superpave mixes were already substantially applicable to the Marshall mixes. This underscores a level of continuity and compatibility between different methodologies, ensuring that vital aggregate characteristics and standards are retained in evolving mix design approaches, thus safeguarding the integrity and performance of resultant HMA products.

A balanced mix design system is the next step in mix design development to enhance pavement performance.

RECENT MODIFICATIONS AND SUGGESTIONS Minimum AC content was a requirement in Marshall mix designs.

However, the Superpave mix design methodology did not enforce that requirement. From the perspective of durability, VMA and performance, most owners and designers still follow the minimum AC requirements as outlined in Marshall for Superpave mixes.

HOT MIX ASPHALT TYPE

MINIMUM AC CONTENT TYPICAL INDUSTRY STANDARD

Superpave 12.5, Superpave 12.5 FC1, Superpave 12.5 FC2

5.0%

Superpave 19

4.8%

Superpave 25

4.4%

THE IMPENDING TRANSITION The Superpave method has emerged as the predominant choice for most agencies in Ontario, although some jurisdictions continue to utilize the Marshall method.

Despite the considerable advantages of Superpave, achieving uniformity in design and quality control/quality assurance (QC/QA) processes across the province presents a tangible challenge. Various agencies continue to leverage their historical experiences with specific mixes to evaluate material and mix quality, reflecting a commitment to tried-and-tested methodologies resulting in a hesitancy toward fully embracing the Superpave mixes. A concise response to this hesitancy in some jurisdictions is that contractors have already acclimated and transitioned to Superpave mixes in Ontario. Consequently, further risk associated with transitioning to Superpave mixes is negligible, signaling a prudent path forward in the realm of asphalt mix design and application.

PERFORMANCE-BASED MIX DESIGN METHOD: SHAPING ONTARIO’S FUTURE MIXES Both the Marshall and Superpave mix design systems fundamentally navigate “volumetric only” methodologies, and performance-related testing mechanisms are absent. However, challenges like adapting to shifting environmental conditions, accommodating escalating traffic levels, and the incorporation of reclaimed asphalt pavement (RAP), underscore a pivotal shift

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towards a performance-based mix design approach. Striking an equilibrium, where acknowledged behaviours like rutting and cracking are managed under traffic and environmental loading scenarios, has now become paramount. Meticulously engineered and installed pavement mixes are essential, serving as a linchpin in ensuring sturdy, durable, and sustainable pavement solutions that can navigate the intricate dynamic environmental and mechanical demands imposed on our infrastructure.

A balanced mix design system is the next step in mix design development to enhance pavement performance. To establish testing conditions that mirror the realities of Ontario, a synergy amongst industry stakeholders, through collaborative laboratory and field trials, is imperative. Deliberations on factors such as the temperature for the Hamburg Wheel Track test require consideration. Modifying the laboratory testing conditions to reflect the specific climate and traffic conditions of Ontario is paramount, ensuring that varied mixtures are crafted to adequately serve distinct applications. Tests like the Disc-Shaped Compact Tension Test (DCT) can be used to assess the low-temperature performance of hot mix asphalt.

In addition, embracing surrogate tests, such as the SemiCircular Bend (SCB) or the Indirect Tensile (IDT) test, which offer expedited turnaround times and augmented QC/QA viability, may emerge as pragmatic alternatives when typical performance testing affects timelines. This approach ensures a fusion of practicality and performance.

Moreover, a performance-based design necessitates vigilant and proactive monitoring during plant production and field implementation, encompassing plant trials. Such trials provide invaluable insights into the capability of a job mix formula (JMF) to be replicated across various types of plants and enable the evaluation of mix performance within established tolerances.

This vigilant oversight not only safeguards the integrity of the design, but also ensures that the implemented solutions adhere closely to the anticipated performance metrics, thereby harmonizing theoretical design and practical application.

CONCLUSION Ontario’s asphalt industry has consistently strived to meet the demands of environmental and traffic conditions. While both the Marshall and Superpave mix design systems bring their

Hamburg Rut Wheel

Disk-Shaped Compact Tension Test

respective merits and limitations, Superpave is more capable of addressing the shifting needs of Ontario’s transportation infrastructure. With an established history in Ontario, Superpave does not necessitate strategic investments in equipment and training, providing a straightforward path towards full-scale implementation. The time is ripe for Ontario to advance towards

Semi-Circular Bend Test

the comprehensive adoption of Superpave hot mix asphalt, thereby ensuring its roadways continue to blend resilience with performance, safeguarding a reliable transport future for all.

Salman Bhutta, Ph.D., P.Eng. is Principal of Engtec Consulting Inc.

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Environmental Stewardship and Improved Asphalt Quality in Ontario

by Doubra C. Ambaiowei

Ontario’s asphalt industry strives to produce the highest quality product. Issues related to asphalt production and paving may arise, but the mind-set is that these challenges are not insurmountable.

One tool to assist in continuous improvement, particularly from a production standpoint, is the OAPC Trillium Award Program. Since 2002, OAPC has advocated to its members to achieve this award via a rigorous assessment process to meet the highest of industry standards and be recognized as the “best-of-the-best.” Plants must complete a self-audit,

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provide the name of a third-party reference, and supply photographs and a short video of their operation to obtain a minimum number of required points in the award categories of appearance, operations, environment, safety, and community relations. To date, 103 asphalt plants have earned the Trillium Award and 147 award renewals have been issued.

ith the high percentage of asphalt plants who have achieved the Trillium Award in the last 20 years, OAPC is evaluating its options on increasing the value of this award for its members and the municipalities they serve.

Stakeholder dialogue has shown two critical considerations: protecting the environment and an overall quality plan aimed at producing asphalt as specified. Trillium-awarded facilities in Ontario subscribe to this commitment and take great pride in conducting themselves as responsible corporate citizens, aiming to exceed environmental regulations and legislation.

They achieve this while employing innovative processes and materials to produce well-priced and high-quality asphalt mixes.

OAPC is dedicated to assisting plant operators to maintain and operate their asphalt plants in a manner that minimizes environmental impact. Therefore, the OAPC Environmental Practices Guide (EPG), with a sixth revision coming soon, forms an integral part of the Trillium Award Program application process. The EPG is an internationally recognized guide and various industry organizations in the U.S. have also adopted its guidelines. The guide provides updated regulatory information, improved descriptions of potential sources of air, noise, waste, and water emissions from asphalt plants, refined environmental best practices, record keeping, and complaints response.

and best approaches toward transitioning the Trillium Award to an Ontario Asphalt Plant Certification program.

This is how we move forward together in the quest for environmental stewardship and improved asphalt quality in Ontario. This message was emphasised at the recent 2023 Municipal Engineers Association (MEA) conference in Sarnia, Ontario, and we welcome continuing engagement from all provincial, municipal and industry stakeholder partners.

Please reach out with questions and inquiries regarding this important subject.

A Trillium Award is a commitment to the environment, quality, and operational safety. Based on a recent OAPC survey of industry and municipalities, about 85 per cent of respondents appear to find value in knowing that their local asphalt plants are Trillium-awarded, while 79 per cent of respondents indicate that they would consider mandating or applying for the award in its current self-regulated form while partnering with OAPC to improve the program requirements. Suggested areas for improvement include “focusing on quality outcomes, seeking ways to build confidence, and collaborating on RAP pilot projects to further the success of experiences that show the durability of HMA is not compromised by incorporating and/or increasing the amount of RAP that is currently allowed.”

A Trillium Ad Hoc Committee, comprised of both municipal and industry stakeholders, is also currently engaged in the continuing dialogue, with an objective to transition the award program from its current self-regulated process toward a third-party inspection certification program within the next three to five years. It is expected that more municipalities will buy in to the program’s current form and include the requirement that plants supplying asphalt have to be Trillium awarded. More importantly, we urge everyone to be a part of the progressive conversations to understand the pros, cons FA L L 20 23 17

EFFECTIVE ASPHALT REJUVENATION

THE KEY TO UNLOCKING RAP’S POTENTIAL

In recent years, our industry has made great strides toward embracing reclaimed asphalt pavement (RAP). Many authorities now encourage or mandate its use, and the number of RAP-bearing roadways around the world increases every year.

by Dr. Krishna Srinivasan

he reason for this enthusiasm is clear: asphalt recycling is a rare example of a practice that’s truly mutually beneficial for business and sustainability. For mix producers, incorporating reclaimed pavement allows them to save on their biggest expense — raw materials. For the environment, it prevents old roads from contributing to waste and reduces emissions by minimizing demand for carbon-intensive virgin materials.

However, there is still a lot of progress to be made. A staggering 750 million tons of RAP are generated globally each year, but less than 20 per cent of it is recycled.

Most of the rest is shipped to landfills.

One obstacle to adoption is uncertainty surrounding the performance of highRAP roadways. Most experts agree that pavements with RAP levels above 25 per cent require a rejuvenator or recycling agent to rebalance the properties of the aged RAP bitumen.

From cooking oil to soft bitumen to petroleum products, a wide range of options promise to optimize aged bitumen for new pavements. Yet, their outcomes are equally diverse. ››

This road in northern Virginia was paved with a high-RAP mix containing ReLIXER. (Sripath) FA L L 20 23 19

Given this variability, it’s useful to define what makes an asphalt rejuvenator truly effective. Unlike a softener, which simply reduces the viscosity of bitumen, an asphalt rejuvenator (AR) or recycling agent also restores its rheological properties and aging behaviour to that of virgin bitumen. An effective rejuvenator must do all of the following: 1) Soften the bitumen; 2) Improve the properties of the bitumen; and 3) Deliver excellent roadway performance and durability.

More than a decade of research and development at Sripath Technologies led to ReLIXER, an asphalt rejuvenator made from bio-based oils. Through the lens of ReLIXER, we can see the many ways that an effective rejuvenator impacts high-RAP mix properties. We can also compare available rejuvenators and view practical examples that showcase the incredible potential of high-RAP mixes when combined with an effective rejuvenator.

BALANCING RUTTING RESISTANCE AND FRACTURE TOUGHNESS Balanced Mix Design (BMD) is an approach to mix formulation that seeks to balance qualities like rutting resistance and fracture toughness while maintaining cost efficiency. The results in Table 1 demonstrate how an effective rejuvenator can be a useful tool for BMD in RAP mixes. In a study conducted on a U.S. roadway, two high-RAP mixes were tested as wear layers: one with 25 per cent RAP and another with 50 per cent RAP. The 25 per cent RAP mix contained 0.5 kg per ton of ReLIXER rejuvenator and 3.4 per cent virgin bitumen PG 64-22.

The 50 per cent RAP mix incorporated 1 kg per ton of ReLIXER and 2.4 per cent virgin PG 64-22. The target for total liquid volume was around 5.6 per cent. By properly adjusting the amount of rejuvenator in each mix, we achieved an excellent balance between rutting resistance and fracture toughness.

RESTORING LOW TEMPERATURE PROPERTIES One of the most important features of an effective rejuvenator is the ability to restore low temperature properties to reclaimed binder. This is a capability that varies widely among commercially available rejuvenators. In a comparative study, samples of a PG 58-20 base binder were combined with three different rejuvenators: Sripath’s bio-based ReLIXER and two other petrochemical-based, binder-softening oils from India and Australia. ΔTc values were measured for each sample.

As shown in Figure 1, the ΔTc value for the binder with 5 per cent ReLIXER was comparable to that of the base binder, whereas the ΔTc value for the petrochemical-oil based rejuvenators was significantly lower. This indicates that ReLIXER imparts much greater durability in the face of temperature stress.

ΔTc (°C) 0.0 -1.0 -2.0 -3.0 -4.0 Base Binder

5% ReLIXER

5% AR2 Petro

5% AR3 Petro

Figure 1: Impact of ReLIXER® and the two petrochemical-oils on ΔTc

DURABLE HIGH-RAP PAVEMENT

The aging behaviour of RAP pavements is highly dependent on the type of rejuvenator used in the mix. Our results show that ReLIXER-dosed mixes maintain exceptional long-term durability, outperforming mixes made with alternative rejuvenators and even matching noMIXTURE TYPE 25% RAP 50% RAP RAP mixes made with entirely virgin binder. Figure 2 illustrates a study which ReLIXER, kg/ton of mix 0.5 1.0 assessed fracture toughness after Virgin bitumen added, % 3.4 2.4 aging for mixes containing 0 per cent, Rutting: Hamburg Wheel-Track Testing 30 per cent, or 50 per cent RAP. The RAP mixes were dosed with either 5 per cent Max Rut Depth, mm 4.19 3.46 ReLIXER or 10 per cent petrochemical Creep Slope, mm/1000 pass -0.11 -0.08 oils. All groups underwent loose mix Fracture Toughness: Ideal CT Test - Short Term Aged Condition oven aging for 4, 8, or 16 hours. The aged samples were then evaluated Ideal CT index 41.7 64.2 using the IDEAL-CT Index, showing that Post-Peak Slope, kN/mm -4.9 -4.1 ReLIXER-enhanced mixes had superior Fracture Toughness: Ideal CT Test - Long Term Aged Condition fracture toughness at both 30 per cent and 50 per cent RAP relative to mixes Ideal CT index 15.7 26.0 dosed with petro-oils. Remarkably, the Post-Peak Slope, kN/mm -10.7 -7.3 high-RAP ReLIXER mixes performed on par with no-RAP mixes, demonstrating Table 1: Impact of ReLIXER on fracture toughness and rutting performance immense restorative capability.

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50

No RAP

5.5% Virgin Bitumen

Control Mix

20

10

40

30

20

10

0

30

Aging Time 4 hrs.

20

8 hrs.

10

0

5.5% Virgin Asphalt (No RAP)

50% RAP

3.02% Virgin Bitumen Added

40

CT Index @ 25°C

CT Index @ 25°C

40

30

50

30% RAP

4.01% Virgin Bitumen Added

CT Index @ 25°C

50

16 hrs.

0

Control 10% 5% Mix Petro-Oil ReLIXER

Control 10% 5% Mix Petro-Oil ReLIXER

Figure 2: CT Index for mixes with varying RAP % and rejuvenator after aging treatments

MOISTURE RESISTANCE ReLIXER imparts moisture resistance to pavement, which improves its longevity. As summarized in Figure 3, the Tensile Strength Ratio (TSR) was measured to compare the moisture resistance of two asphalt mixes. The control mix, based on the Australian multi-grade M1000 binder with 15 per cent RAP, had a TSR value of 70 per cent. In comparison, a mix based on the M1000 binder with 40 per cent RAP and dosed with 3.2 per cent ReLIXER had a TSR value of 85 per cent.

strongly to aggregates, showing better stripping resistance with a 4.25 per cent CWL.

% Cantabro Weight Loss PG 58-28 Binder

8 6 4 2

Tensile Strength Ratio (TSR), % 100 80

0 Base Mix 20% RAP

Australian M1000 Binder

60

40% RAP + 5% AR-B6

40% RAP + 5% ReLIXER

Figure 4: Comparing stripping resistance (Cantabro Weight Loss) for two bio-oil rejuvenators in PG 58-28; 20% or 40% RAP; 5% ReLIXER by wt. of binder

40 20 0 Base Mix M1000 + 15% RAP

M1000 + 40% RAP + 3.2% ReLIXER

Figure 3: Tensile strength ratio for Australian binder M1000 + 15% RAP versus M1000 + 40% RAP + 3.2% ReLIXER

STRIPPING RESISTANCE Figure 4 shows the percentage Cantabro Weight Loss (CWL) for three asphalt mixes: (1) a base mix containing 20 per cent RAP; (2) a mix with 40 per cent RAP and 5 per cent AR-B6 rejuvenator; and (3) a mix with 40 per cent RAP and 5 per cent ReLIXER. All three mixes were based on a PG 58-28 grade binder. The base mix and the AR-B6 dosed mix had a similar stripping resistance, showing a 7.6 per cent and 7.7 per cent CWL, respectively. The ReLIXER-dosed mix held on more

COMPARISON TO SOFT GRADE BITUMEN While “softer” grades of bitumen are commonly used to rejuvenate high-RAP mixes, the methods used to achieve this softening can substantially affect the mix’s final properties.

Figure 5 depicts the aging behaviour of a base bitumen, a rejuvenated bitumen dosed with ReLIXER, and a softer grade bitumen obtained from the same source as the base bitumen. Samples of each were aged in a Pressure Aging Vessel (PAV) and subjected to Bending Beam Rheometer (BBR) tests to determine their ΔTc values. As seen in the figure, the rejuvenated sample closely maintains the ΔTc characteristics of the base bitumen, while the softer grade bitumen has an unacceptably high ΔTc value after aging, demonstrating that the ReLIXER-rejuvenated binders had better aging characteristics than this softer grade binder. ›› FA L L 20 23 21

Base Bitumen B As Received

“Softer” Bitumen As Received

-25.7

67.1

-33.8

58.2

Δ -5.4°C 2X PAV

2X PAV

-20.3

94.3 High Temperature True Grade

Δ -11.6°C

Low Temp True Grade

-22.2

88.1 High Temperature True Grade

Low Temp True Grade

“Rejuvenated” Bitumen Treated Asphalt

59.1

Better than “Soft” Bitumen

-32.8

Δ -5.1°C 2X PAV

79.5

-27.7

High Temperature True Grade

Low Temp True Grade

5% ReLIXER added to Base Bitumen B Figure 5: Aging behaviour of ReLIXER versus a softer bitumen

CASE STUDIES One case study on a 100 per cent RAP roadway in New York City exemplifies the incredible potential of high-RAP mixes when paired with an effective rejuvenator.

A stretch of road in New York City that is subject to very high traffic volume, stopand-go traffic, and extreme weather patterns was paved using a 100 per cent RAP mix. ReLIXER was sprayed directly onto RAP particles at a dosage of 0.55 per cent by weight of the mix, with no virgin binder or aggregates added. Field core samples were obtained nine months after paving. The results of the laboratory tests and field core sample tests from this trial are summarized in Table 2 and Table 3.

Despite using entirely reclaimed materials, the road met all specifications established by local authorities. The trial mix had 3.9 per cent Marshall Air Voids, stability of 2110 kN, and flow of 9.9 mm. Rutting resistance was 10.9 mm at 10K cycles and 14.6 mm at 20K cycles. The Semi-Circular Bend (SCB) fracture toughness of cored specimens after one year of service had a JC value of 0.71 kJ/m2 at 25°C. Meanwhile, a contractor in northern India laid down a DBM II base course with two RAP mixes: one with 50 per cent RAP and 0.2 per cent ReLIXER and the other with 60 per cent RAP and 0.3 per cent ReLIXER. Respectively, the results showed Marshall Air Voids of 3.1 per cent and 3.23 per cent; Marshall Stability values of 15.2kN and 15.1 kN; and flow measurements of 3.1 mm and 3.2 mm. The customer now routinely uses

high-RAP mixes along with ReLIXER for base-course paving applications, not just in the north but throughout India.

In Dublin, Ireland, Roadstone Ltd. conducted a field trial on a roadway to evaluate ReLIXER’s impact on a 60 per cent RAP mix. This trial considered two dense base mixes with 40/60 grade bitumen: AC20 and AC32. A control mix containing no RAP or rejuvenator and a ReLIXER-dosed mix with 60 per cent RAP were prepared for each mix type.

Shown in Table 4, mixes with 60 per cent RAP and ReLIXER had improved compaction levels for both AC20 and AC32. Bulk density and air voids also stayed at sufficient levels after the addition of rejuvenated RAP. Indirect Tensile Strength Ratio (ITSR) values were very similar for high-RAP and no-RAP mixes, indicating acceptable moisture resistance in the rejuvenated mix. HighRAP mixes displayed acceptable Wheel Tracking Slope (WTS) and stiffness results compared to no-RAP control mixes. The addition of the rejuvenator restored penetration of the bitumen extracted from high-RAP mixes to values close to the no-RAP extracted bitumen.

The virgin 40/60 bitumen showed a penetration of 51 dmm. By using fewer virgin materials, the contractor was able to make a substantial dent in their CO2 emissions. All mixes tested met specifications established by Ireland’s public transport agency.

SUMMARY These data underscore the importance of effective rejuvenation in harnessing

LAB DATA Using Marshall

AIR VOIDS %

STABILITY kN

FLOW mm

FIELD CORE DATA

Avg. SCB @ Hamburg @10K Air Voids 25°C mm % JC, kJ/m2

0.55% ReLIXER

3.9

2110

9.9

0.55% ReLIXER

4.1-4.3

0.71

10.9

14.6

Specification

3.5-5.5

>1500

8.0-12.0

Specification

35.5-5.5

0.50

<12.5

Tertiary

Table 2: Marshall data for 100% RAP trial mix

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Rutting @20K mm

Table 3: Semi-Circular Bend (SCB) and Hamburg Wheel-Tracking (HWT) results for NYC field core samples

MIX

Stifness MPa

Water Sensitivity ITSR

Permanent Deformation WTSAir

Penetration dmm

Total GWP kg CO2e/T

AC20: No RAP, No Rejuvenator

3300

94

0.26

45

51

AC20: 60% RAP + ReLIXER

3100

90

0.33

40

45

AC32: No RAP, No Rejuvenator

4500

91

0.12

45

55

AC32: 60% RAP + ReLIXER

4100

90

0.24

38

46

Table 4: Performance of 60% RAP roadway in Dublin, Ireland

Laboratory evaluations and field studies show the benefits derived from high-RAP mixes when paired with an effective rejuvenator.

the full potential of RAP. Through laboratory evaluations and field studies, one can observe the tangible benefits that can be derived from high-RAP mixes when paired with an effective rejuvenator. From improved mix properties to enhanced road performance, these findings provide a clear roadmap. As the industry continues to lean towards sustainable practices, it’s crucial to base decisions on robust technical evaluations. With a focus on maximizing RAP use and ensuring optimal rejuvenation, the path forward promises both economic and environmental advantages.

Dr. Krishna Srinivasan is president of Sripath Technologies LLC in New Jersey, USA. FA L L 20 23 23

SUSTAINABILITY AND ESG IN THE ASPHALT INDUSTRY

by Donn Bernal

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The word sustainability is being used generously nowadays. The Merriam-Webster dictionary defines it as “being a method of harvesting or using a resource so that the resource is not depleted or permanently changed.” So how does sustainability work in asphalt? The word can be applied to many things including materials and processes.

However, it is taken a step further in the corporate or business world and more aptly known as ESG or Environment, Social, and Governance. In the asphalt industry, there is much we can do to have a large impact on ESG, particularly on the “E”.

n recent years, owners such as the municipalities and the provincial government have started to face pressure by their constituents to have an ESG policy including reviewing their environmental practices for a net zero future. Many private and public corporations are now building carbon effects into their bidding practices. There are many things the asphalt industry is already doing to be sustainable to contribute to the “E” in ESG, and a number of these processes or technologies are mainstream enough to make an impact to the environment.

We, as an industry, must be prepared with tools, resources, and information to show that asphalt is one of the most sustainable materials in the world, ensuring that it continues to be the product of choice.

We are also seeing states such as Colorado building environmental best practices such as environmental product declarations (EPDs) into their bidding and contract requirements.

EPDs measure the cradle-to-gate CO 2 equivalent effects as it has little to no control over the rest of the pavement life cycle that includes construction, use, maintenance and rehabilitation, and end of life. “Cradle-to-gate” is a phrase that you will hear a lot when sustainability is discussed and looks at the carbon impact of a product or material. In the case of asphalt mixtures, it includes the carbon effects of the extraction of the aggregates and asphalt cement, the transportation to the asphalt plant, and the manufacturing of the asphalt mixture right to the point it leaves the gate of the asphalt plant.

Through the National Asphalt Pavement Association (NAPA), the U.S. already has a system in place for asphalt to create EPDs and Ontario is working on a similar system with the support of OAPC, NAPA, and the National Research Council (NRC). If and when this happens, the system can be expanded across Canada.

NRC Canada through its research program is committing to reduce its greenhouse gas (GHG) emissions by 40 to 45 per cent by 2030 (relative to 2005 levels) and net zero emissions by 2050.

It is imperative that they support the areas of construction practices/construction materials and bio-energy to reach these ambitious goals.

How can we as an industry support environmental best practices? It starts with the ingredients of an asphalt mixture — aggregates and asphalt cement. We must make a conscious decision about the materials’ carbon emissions and where the materials are purchased from. It is no longer just about the price but also the carbon emission equivalent effects. Aggregates and asphalt cement suppliers will also have their own EPDs to help you make this decision.

Next, we will not be able to control the fuel that the carrier uses to get the materials to the asphalt plant, but we can control the distance travelled to the asphalt plant to reduce the carbon emission equivalent effects. All these variables are part of the EPD equation. There are logistics companies in North America trialling trucks that are electrified or using hydrogen, but that is still in the early stages. These initiatives will reduce emissions

Asphalt Cradle-to-Gate and Pavement Life Cycle.

(NAPA’s Emerald Eco Label EPD for Asphalt Mixtures) and help the EPD. Emissions from material extraction and transportation are one of the largest sources of CO2 equivalent emissions in an EPD, so it is important that the suppliers and carriers we choose have similar mandates that our asphalt industry is progressing to and want to achieve as it pertains to sustainability.

With the sources of materials selected, the asphalt mix design can play an important role as well in developing a sustainable pavement. Even in operational best practices, the asphalt mix design is often overlooked. Having the correct combination or proportion of aggregates can help reduce moisture content, start/stops at the plant, and material wastage.

Reclaimed asphalt pavement (RAP) plays a key role in reducing the CO 2 equivalent emissions. Since RAP has already gone through the plant once before, it is not double counted in the EPD calculations. So not only are we recycling the aggregates and asphalt and reducing material cost, CO 2 equivalent emissions have been significantly been reduced as well for the asphalt mixture. A win-win situation!

Warm mix asphalt technology is the second significant item to RAP that improves sustainability of the asphalt. By allowing the plant to operate at a lower temperature of as much as 20 degrees Celsius, CO 2 equivalent emissions are reduced significantly and the life expectancy of the asphalt mixture ››

FA L L 20 23 25

systems will help as well. And the electrified pavers that are in development or being trialled will change the paving industry. The carbon emission equivalent effects at the paving stage haven’t been studied or measured as much as the cradle-to-gate component but it is also progressing to get us to the net zero goal.

Donn Bernal is working with SolarSteam, a commercial/industrial renewable energy start-up company. is improved as the asphalt cement is not oxidized at the same degree as in hot mix asphalt. This is a technology that we must embrace more as it is a proven technology through studies and trials for the last 20 years. It is time to make it mainstream in Ontario and Canada.

Asphalt technology innovations such as warm mix asphalt, performance enhancing (rutting resistance, thermal cracking resistance, fatigue resistance) additives, and efficient material use including the use of RAP all play a part in a better performing pavement. Furthermore, asphalt pavement’s sustainability could be improved by using long-life asphalt mixtures produced by using a balanced mix design approach defined in AASHTO PP105-20 as “asphalt mix design performance tests on appropriately conditioned specimens that address multiple modes of distress taking into consideration mix aging, traffic, climate and location within the pavement structure.”

The asphalt industry can also play a role in the other two components of ESG. The Social component is the organization’s impact on society internally and externally. This could mean how its treats its employees, how it evaluates and chooses it supply chain, and community relations. Within the asphalt industry and our associations, we see scholarship or development programs for skilled trades, Women in Asphalt, and diversity and inclusion initiatives. These all contribute to make an impact on society and especially our employees and families.

The Governance component applies to how to make impact investments in the company to ensure its sustainability and not just focusing on profits. What financial measures can be put in place so that people and planet are accounted for in the equation? It can also be called sustainable investing.

Even a small business can commit to Social and Governance practices.

These commitments can be evaluated internally or be advertised publicly to inform investors or stakeholders of the business’s sustainability practices.

At the asphalt plant, reducing energy usage and emissions are the prime methods to run an efficient operation. Reducing moisture at the stockpiles, keeping the loader bucket 12 inches from the ground to feed the cold feed bins, insulating the dryer shell, managing plant start and stops, and more effective pipe insulation are just some of the many best practices at the plant. It can be taken a step further by looking at alternate energies and technologies. We are not quite there to switch 100 per cent to hydro power or renewable energy with the amount of energy required to turn the large motors and heat the aggregates, but components of the operation can be converted. The use of wind, solar, and steam energy technologies have advanced significantly to provide energy with minimal efficiency losses that it can make a significant enough effect in cutting down carbon emissions at the asphalt plant. In the meantime, switching to natural gas or liquified natural gas from fuel oil or recycled oil helps the asphalt plant run cleaner.

There is lot of information to learn and understand with new and exciting concepts that are constantly evolving, but the basics don’t change: if we continue to strive to operate efficiently and be conscious of reducing emissions in various ways, we will be more than halfway to an “overall” sustainable asphalt pavement. And if we can make conscious decisions and collaborate/partner with all the stakeholders, the ambitious GHG emission targets can be achieved and sustainability attained.

At the paving operation, new technologies such as intelligent compaction which uses GPS — and most likely AI in the future — to aid the roller operator to create efficient rolling patterns is already happening. More efficient engines and carbon capture

Donn Bernal, P.Eng, MBA is Principal of Corfinium Solutions Inc. (corfinium.xyz).

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2023 ASPHALT TECHNICAL SYMPOSIUM RECAP

by Chris Campbell

June 13 marked the 5th annual Asphalt Technical Symposium (ATS) sponsored by the Ontario Asphalt Pavement Council (OAPC). This year’s event took place at MTO’s Centre for Excellence in Transportation Infrastructure (CETI) in North York. The event kicked-off with a series of presentations on industry challenges and opportunities followed by a tour of MTO’s new lab facility.

The Asphalt Technical Symposium is a platform to encourage and improve dialogue between stakeholders in Ontario’s asphalt Industry with the following core objectives: 1. Provide a platform for unbiased technical discussion and sharing; 2. Educate each other on the specific elements of technology necessary to achieve high performing asphalt pavement including materials, design and construction practices; 3. Respectfully share different points of view and visions to improve asphalt pavement quality; and 4. I dentify and develop a list of technical topics and agree on next steps to adequately address them.

This year’s symposium featured a summary of the Ontario Mix Asphalt Program (O-MAP) study which was presented by Ontario Asphalt Expert Task Group (OAETG) Chair, Sina Varamini.

Varamini provided insights into the second phase of the study to understand potential variability and risks of implementing performance testing in Ontario based on existing methods and limits. This phase focused on one plant-produced mix to help minimize variability and engaged multiple labs to progress testing through various test methods such as Hamburg Wheel Track test and Semi-Circular Bend test. The results indicated that significant variability still exists between the participating labs on some of the tests, and recommendations were provided in hopes to minimize this moving ahead. Some ››

FA L L 20 23 27

great dialogue followed the presentation to support O-MAP in next steps as they work this challenge.

The ATS next changed focus to reclaimed asphalt pavement (RAP) by highlighting current high RAP experiences in Ontario as well as identifying where high RAP practices are currently used globally. Tyler Renaud, QA Project Manager for the City of Hamilton, started us off with an overview of work they had completed in the Hamilton area on both Book and Monarch roads using mixes containing up to 40 per cent RAP. Both locations show minimal to no unexpected degradation and are continuing to be monitored. Renaud’s presentation was followed up by Mike Aurilio, Terminal Manager at Yellowline Products Ltd., who provided a literature review of global high RAP experiences. This presentation helped to highlight how other regions manage higher RAP incorporation and what Ontario can do to start the process while managing risks.

The next topic was a shared presentation titled “Future of Asphalt Binder Testing” by Amma Wakefield, Asphalt Institute Canadian Regional and Research Engineer, and Chris Campbell, Imperial Oil Americas Asphalt Technical Lead. This presentation focused on a review of the proposed asphalt binder tests that have recently come out of the National Cooperative Highway Research Program reports 09-59, 09-60 and 09-61. Wakefield provided a brief background on asphalt pavement concerns over recent history and how they are being addressed. She then focused on the concerns that these NCHRP reports are

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trying to resolve, like fatigue, durability, and laboratory aging.

Campbell continued with concerns that these new tests bring, both in their science and potential implementation, that should be addressed before progressing to implementation. He also shared a few alternative tests that are simpler and could be more effective at addressing some of the concerns.

Our final presentation of the day was “Performance Testing on Asphalt Mixtures” by Gelu Vasiliu, Head of Bituminous Section at MTO. Here Vasiliu shared the results that MTO have been seeing on samples tested for flexibility index (FIT), Disk-Shaped Compact Tension (DST), and Hamburg Wheel Track (HWT). Gelu also shared insights into preliminary acceptance criteria for these tests and some next steps on mix performance testing in Ontario.

More detail on these presentations can be found on the OAPC website under “Publications & Education”.

Having now successfully completed five symposiums, the ATS team look forward to reviewing feedback from this session as we set our sights on the next event in 2024. We hope that all who attended this year’s event found it informative and worthwhile, and enjoyed the technical presentations and discussions. If you have any questions about this event, please reach out to Doubra Ambaiowei at OAPC. Chris Campbell is Americas Asphalt Group & Technical Lead for Imperial Oil and ATS co-chair.

2023 ANNUAL MEMBERS’

GOLF TOURNAMENT Held at the Cardinal Golf Club in King Township on August 31, the sold-out ORBA/OAPC Annual Members’ Golf Tournament featured three courses and 400 golfers. Thanks to everyone and especially our sponsors for making this such a successful day.

FA L L 20 23 29

WHAT IS THE CURE TIME FOR ASPHALT? An engineer colleague recently reached out to me and asked, “What is the cure time for asphalt?” My initial response to his question was “Are you referring to cold-mix asphalt?”

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by Dr. Grover Allen

old-mix asphalt is a mixture of asphalt and a solvent and/or water, aggregates, reclaimed asphalt pavement (RAP) and other minerals typically used for patching and for repair of small sections of pavement. The asphalt and solvent portion, excluding the other components of the cold mixture, is often referred to as “cutback asphalt.”

Evaporation, or curing, of these components – solvents and/ or water – in a cold-mix asphalt leads to the hardening of the asphalt mixture. I assumed this was likely what my colleague was referencing with his question. Another thought occurred to me that he may be referring to an asphalt emulsion which is an aqueous solution containing tiny droplets of suspended asphalt meant to be applied in ultra-thin layers on or within a pavement structure.

Asphalt emulsions also require the evaporation of water and a relatively short “cure time.” However, it is not common or appropriate to refer to these products as “asphalt” without including some type of additional descriptors, such as “coldmix”, “cutback”, or “emulsion.” When the word “asphalt” is used without a descriptor, it is most commonly referring to an “asphalt mixture”, which includes the heated liquid asphalt and aggregates that are compacted to build a typical roadway; otherwise, the term “asphalt” may be referring solely to the hot liquid asphalt portion of the mixture. “Hot-mix asphalt” is a term often used to refer to an asphalt mixture, and “warm-mix asphalt” may also be used to describe an asphalt mixture that is either processed with an additional additive or using foaming techniques that allow the temperature of the mixture to be reduced slightly, although the mixture is still very hot.

SIMPLE ANSWER Asphalt is liquified by applying external heat, which allows it to be mixed, transported and compacted and the mixture rapidly hardens as heat dissipates and achieves full strength upon cooling to ambient temperature. Therefore, I want to make this as clear as possible – asphalt, which is the material used to build 94 per cent of our roadway infrastructure in the U.S., does NOT have a cure time.

Asphalt begins to cool immediately after mixing and cooling continues during transport, construction and postconstruction. It will typically gain full strength and can support traffic within minutes after construction but can take hours in rare cases, depending on lift-thickness, ambient conditions and other variables.

COMPLEX ANSWER For the more technical readers, there are two key temperature ranges that should be considered to ensure that asphalt construction operations cease and traffic operations commence at the proper times:

1. C essation temperature (internal asphalt temperature in which all construction operations must cease to prevent damage caused by construction equipment) 2. Maximum ambient temperature (internal asphalt temperature below which a newly constructed asphalt pavement has cooled sufficiently to be trafficked without causing premature damage) The internal portion of an asphalt pavement during construction and immediately post-construction may be slower to cool than the surface. This effect can be much more pronounced for pavement lifts thicker than two inches, so internal temperature may be temporarily higher than surface temperature until equilibrium is reached. For pavement lifts two inches and thinner, the surface temperature is a more reasonable approximation of internal temperature during the cooling phase.

Asphalt Institute’s MS-22 “Construction of Quality Asphalt Pavements” says the following about cessation temperature: “Compaction should be completed before the internal mix temperature falls below what is referred to cessation temperature, typically around 175-180°F (80-82°C). The cessation temperature will vary from project to project.

Therefore, it is important to establish a target cessation temperature at the beginning of each project.”

Once an asphalt pavement has cooled to ambient temperature, surface temperature will closely trend with ambient air temperature, but due to the effects of surface heat radiation, pavement temperature is typically greater than the ambient air temperature. For example, if it is 90°F outside, the pavement surface may be up to 120°F or greater, depending on UV intensity and other factors. The precise post-construction maximum pavement temperature permitted for traffic opening will differ based on the climate and materials selected for construction.

CHOOSING A BINDER Performance-graded asphalt binders are selected based on a design maximum pavement temperature 20 mm below the pavement surface. This design value is dependent on a maximum air temperature and the geographical latitude for a given region. For example, there is more than 99 per cent reliability that a pavement temperature will not exceed 136.4°F (58°C) in Cleveland, Ohio. Therefore, a pavement constructed with a PG 58-28 grade binder in Cleveland, Ohio would be ready to open to traffic once the internal pavement temperature post-construction has cooled below the maximum design temperature of 136.4°F (58°C). In a hotter climate, such as my home state of Florida, a stiffer grade of asphalt, such as PG 76-22, is commonly specified.

An asphalt grade that can support traffic at a temperature up to 76°C (168.8°F) means that a newly built roadway should be ›› FA L L 20 23 31

The lack of a cure time for asphalt, or its speed of construction, is one of the unique advantages of using asphalt as the primary roadway building material. able to open to traffic very shortly after final roller pass occurs between 175-180°F. This matches closely with the language shown in the Florida Department of Transportation’s (FDOT’s) Specification Section 330-10: “To prevent rutting or other distortion, protect sections of newly finished dense-graded friction course and the last structural layer before friction course from traffic until the surface temperature has cooled below 160°F.” The specification then goes on to say the contractor may use artificial methods to cool the pavement and may be directed to do so when it is desirable to open the pavement at the earliest possible time. Therefore, the required time to open a newly constructed two-inch asphalt surface to traffic would generally be just a few minutes. Thicker lifts will take longer to cool internally, and in rarer cases of asphalt construction, it could take hours. DOT and airfield project engineers or other representatives present at the construction site may give the order when an asphalt pavement is ready to be opened to traffic.

The lack of a cure time for asphalt, or its speed of construction, is one of the unique advantages of using asphalt as the primary roadway and airfield building material and an attribute which makes it uniquely different than portland cement concrete (PCC). The load-bearing capacity of PCC is normally measured and estimated according to its compressive strength over a slow curing time.

A typical strength-gain curve for PCC is: • 1-day: 16% • 3-day: 40% • 7-day: 65% • 14-day: 90% • 28-day: 99%

HONEST QUESTION Back to my engineering colleague who asked, “What is the cure time for asphalt?” to which I responded, “Are you referring to cold-mix asphalt?” He responded: “No, I’m referring to hot-mix asphalt.”

Now, let me provide a little more background on my engineer colleague. He’s no rookie. He’s a very accomplished engineering professional. His engineering career has mostly encompassed working with structures, including concrete mix design, concrete construction, blast testing, blast mitigation, etc., and he’s been practicing engineering for over 30 years. He will soon retire.

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When he clarified his question, one thing occurred to me.

If a structural engineer with decades of experience does not understand that asphalt does NOT “cure”, there must be an abundance of other individuals involved in public service, infrastructure project planning, construction, design, life cycle analysis, infrastructure safety planning, user-delay analysis, etc. who also do not understand this.

At this point in the article, you already have more background about asphalt strength-gain than my engineer colleague with over three decades of engineering experience. That is the primary reason I felt compelled to write this one.

MISINFORMATION I wanted to better understand where he and others might be getting their information about asphalt, so I went to the Google search bar and typed in “What is the cure time for asphalt?” The results, which you can verify for yourself, were very disappointing. Nearly every search result, including the following examples, falsely indicates there is a cure time associated with asphalt construction: • “ 6-12 months” • “It can take up to a full year for asphalt to cure, but within 30 days asphalt is cured to a point it can be driven on” • “ 48-72 hours to dry completely” • “Asphalt takes six to twelve months to fully cure and remains a little more susceptible to damage for that time” • “ The drying process happens in phases. Your asphalt may look and feel dry, but a complete curing typically takes much longer than three days.”

Almost none of the information returned in the Google search accurately answers the precise question my colleague asked, which I admit, was quite surprising to me. At best, the information is extremely misleading, and at worst, it results in the implementation of poor infrastructure policy based on a misunderstanding of how asphalt gains strength after placement.

Now I understand why my colleague was confused about how asphalt hardens and why just about anyone else outside of the asphalt industry might be also. I learned a couple of lessons in this case –don’t assume what others might know and understand, and always verify the information found on the internet.

If you have any asphalt-related questions, please do like my engineer colleague, and come to a trusted source of information, such as the Asphalt Institute. We can’t eliminate misleading information on the internet, but we can provide accurate answers to questions like this, and even much tougher questions presented by practitioners, engineers, the general public, those interested in transportation and particularly those involved in making important transportation investment decisions impacting billions of dollars in infrastructure funding.

Grover Allen, Ph.D., P.E is an Asphalt Institute Regional Engineer based in Florida. This article appeared in the spring 2023 issue of Asphalt magazine and is reprinted here with permission from the author and publication.

UNSUNG HEROES

by

Steve Pecar

Quick study doesn’t let years get in the way of experience

Murdoch

Tyler Murdoch ometimes, experience is not just measured in years.

Just ask the folks at Yellowline Asphalt Products Ltd. about Tyler Murdoch’s knowledge of the business and his ability to perform under pressure.

“Tyler is a guy you can count on, day in and day out,” says Mike Aurilio, manager of the Yellowline plant in Hamilton. “He hasn’t been in the business as long as others but he knows his job and he knows how to do it well.”

Aurilio says that his colleague has always been a quick study and eager to learn new things — two factors which have allowed him to rise through the ranks and become foreman.

He points out that Murdoch has been with Yellowline almost since day one and from the start began learning as much as he could about the job and making himself invaluable to the company. “Guys like Tyler just keep working and learning, taking on responsibility and getting things done, and that’s a valuable part of any workplace,” Aurilio says.

As foreman, Murdoch has many roles to fill. In the yard he’s responsible for loading and unloading, dealing with various contractors, solving problems and fixing anything that needs to be fixed. What’s more, Murdoch makes sure his team learns along with him, sharing the credit when a task is done well and not afraid to lend any of the knowledge that he acquires on the job.

“He cares more about just himself,” explains Aurilio. “He cares about the job, the company and about other workers. He wants to see everyone be successful and understands how everyone works and what their skills are and he is able to get the best out of people.”

Murdoch appreciates the accolades but quickly points out that he has been lucky to be around good people who have helped him along his journey. He admits that when he started

at Yellowline he was very green and had little experience in the work he was about to undertake, but others were there to teach him the tricks of the trade.

“I worked in a gravel pit when I first started out so I didn’t know that much about the rest of the industry, but when the opportunity came up at Yellowline I thought I would give it a shot,” Murdoch laughs. “The rest, as they say, is history!”

Part of that history was working alongside Earl Mahoney who mentored Murdoch in his early days at the company. “Earl showed me everything,” Murdoch says. “He had the experience and he was somebody I looked up to. He took me under his wing and showed me what needed to be done and how to do it.”

That learning experience has stuck with Murdoch and helps him with his day-to-day routine whether it’s offloading railcars, barges and ships, dealing with repairs, and making sure everything runs smoothly.

Murdoch also credits the people he works with for meeting all the demands of the job. He explains that many of them started out at Yellowline together and have worked well together over the years. “We help each other,” Murdoch says. “And we all have different skills and expertise. We teach each other every day.

When one of us learns something we share that information.”

Murdoch says he’s proud to have been with Yellowline at the beginning to watch the company grow. He looks forward to coming to work each day knowing that he is part of a team that likes to get things accomplished.

“I like what I do,” he says. “I like being in the yard with the guys; I like the way I have been treated. I’ve learned a lot and there is still much more to learn. I look forward to it.”

Steve Pecar is a Mississauga-based writer, editor and designer.

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TECHNICALLY SPEAKING Doubra C. Ambaiowei Director, Technical Services

Innovations in sustainability for asphalt pavements – airfield in focus OAPC’s strategic priority on sustainability seeks to promote asphalt strategies, initiatives and processes that will benefit the environment, improve society, and provide an overall economic benefit. To that end, I recently presented and participated in a panel discussion at the Canadian Airfield Pavement Technical Group (CAPTG) workshop during the 2023 Summer Winter Integrated Field Airfield Technologies (SWIFT) conference held in Winnipeg, Manitoba. This presentation provided yet another opportunity to advance our collaboration with the National Asphalt Pavement Association (NAPA) who spoke this year’s Partners-in-Quality Road Tour on Environmental Product Declarations (EPDs) for asphalt mixtures.

Sustainability is not a new concept – Cicero, on Old Age, 44 B.C.

Using the example of olive trees which can take decades to fully mature and bear fruit to illustrate that sustainability is not a new concept, our presentation outlined both NAPA’s and OAPC’s position on sustainability as a key pillar to meet the needs of the current generation without compromising the needs of future generations, ensuring a balance between economic growth, environmental care, and social governance.

The presentation outlined some reference resources on the requirements for a sustainable asphalt pavement from NAPA and the Federal Highway Administration (FHWA), each emphasizing the need to achieve the engineering goals for which asphalt pavements are constructed; preserve and (ideally) ›› FA L L 20 23 35

restore surrounding ecosystems; use of financial, human, and environmental resources economically, and meeting human needs such as health, safety, equity, employment, comfort, and happiness (work-life-balance).

Another highlight from the presentation on the coming paradigm shift pertaining to embodied carbon reduction was a focus on procurement policies being implemented and/or under development in the U.S. and Canada. These include:

The presentation’s focus on innovation for asphalt pavements highlighted NAPA’s action plans and programs on cutting down environmental emissions, and measuring the industry’s embodied carbon using EPDs and Life Cycle Assessment (LCA) tools. EPDs provide quantified environmental information on the life cycle of a product to enable comparisons between products fulfilling the same function.

• T he Federal Buy Clean Initiative: Through Buy Clean, the American government is for the first time prioritizing the use of American-made, lower-carbon construction materials in federal procurement and federally funded projects, and this is advancing America’s industrial capacity to supply the goods and materials of the future while growing good jobs for American workers.

ORBA/OAPC have begun to forge new partnerships and investments that would result in adapting NAPA’s Eco-Emerald Label EPD Software for Canada/Ontario users, as well as harness the National Research Council Canada (NRC) funding support to develop regionalized LCA report and Life Cycle Inventory (LCI) datasets for asphalt mixtures produced in Canada, with Ontario as a starting point.

• I ndustrial Deep Decarbonization Initiative - Green Public Procurement Pledge: This is currently focused on cement, concrete, and steel, but we understand that the Canadian government has held discussions with internal stakeholders and industry and supplier stakeholder groups on the possibilities for asphalt. The NRC’s platform to decarbonize the construction industry at scale appears to be in alignment with this initiative and is a perfect fit for ORBA/OAPC to harness partnerships, collaborations and investments into education, research, and new and existing technologies capable of advancing the asphalt industry’s sustainable strides — a welcome development!

• Greening Government Initiative – Policy on Green Procurement: This is managed by the Treasury Board of Canada with a focus on developing a standard on embodied carbon in construction but does not currently apply to asphalt.

The presentation concluded with highlights about opportunities in airfield pavement sustainability research including: • T he FHWA Airfield Pavement LCA Framework Final Report: This report highlights recommended guidelines for all phases of LCA (goal & scope definition; inventory development; impact assessment; interpretation & critical review; and reporting), four case studies, and some details of an airfield pavement LCA tool under development.

• Airport Asphalt Pavement Technology Program (AAPTP): NAPA coordinates and manages $9 million FAA-funded research through a co-operative agreement. This program includes developing and co-ordinating implementation plans; developing and conducting webinars, training, workshops, and conferences for the FAA; preparing new or updating existing written technical publications, compilations of findings, and presentation materials; and supporting stakeholder engagement. The program

36 OA P C | ASP H A LTOP IC S

may include research needed to adapt technology for use in airport asphalt pavement mixtures or pavement applications.

This effort will leverage the unique technology implementation capabilities of NAPA with assistance of the FAA and industry, to advance deployment and adoption of innovative asphalt material technologies.

Other on-going AAPTP projects include: • A $500,000 research study in collaboration with University of California at Davis, with the objective to assess the feasibility of cold central plant recycling (CCPR) of asphalt mixtures for all categories of airports. A final report is expected by 2025.

• A $1,200,000 research study in collaboration with the National Centre for Asphalt Technology (NCAT) to develop a framework and recommended standards for improving resilience to extreme weather events and climate change. A final report is expected by 2025.

• A focus on Balanced Mix Design (BMD) to evaluate rutting and cracking in airfield pavements.

• Improving Performance of Longitudinal Joints.

• Mitigation of Plastic Flow and Delamination at High-Speed Exits.

We are pleased to have had NAPA’s collaboration in developing the SWIFT/CAPTG presentation and are always happy to join forces with industry leaders from the Cement Association of Canada and WSP in Canada to promote the important discussions on innovations in pavement sustainability.

If you would like to learn more, or are interested in a copy of the presentation, please connect with me at Doubra.Ambaiowei@ orba.org.

04 AGGRESSOR

www.aggressorautomation.com

39 CCIL

www.ccil.com

43 CANADIAN ASPHALT

www.canadianasphalt.ca

34 ENGTEC

www.engtec.ca

15 FLO COMPONENTS

www.flocomponents.com

06 G ENCOR INDUSTRIES www.gipi.com

23 GIP

www.geneq.com

08 LIUNA

www.liunaopdc.ca

17 M&L TESTING

www.mltest.com

44 McASPHALT

www.mcasphalt.com

28 NHES

www.NHES.ca

36 TROXLER CANADA www.troxler.ca

27 UPPER CANADA ROAD SERVICES Inc.

www.uppercanadaasphalt.com

L-R: Tim Smith, Cement Association of Canada, Doubra Ambaiowei, ORBA/OAPC, and Maeri Machado, WSP in Canada were panelists in the discussions on Sustainability in Airfield Pavement Design & Construction, during the CAPTG Workshop at the 2023 Summer Winter Integrated Field Airfield Technologies (SWIFT) conference in Winnipeg, Manitoba.

02 WIRTGEN

www.wirtgen-group.com

03 YELLOWLINE

www.yellowline.ca FA L L 20 23 3 7

ENVIRONMENTAL ESSENTIALS Doubra C. Ambaiowei Director, Technical Services

Saving the environment – a collaborative goal with RAP A key tactic to OAPC’s strategic priority on sustainability calls for the development of an action plan to meet the government’s commitment to net-zero by 2030 and 2050 respectively. Another emphasizes addressing provincial and municipal specifications to optimize the use of reclaimed asphalt pavements (RAP) and warm mix asphalt (WMA).

We believe that concentrating on the performance outcomes of using RAP is a better driver toward achieving the associated environmental benefits of reduced greenhouse gas (GHG) emissions. Incorporating RAP results in reduced energy consumption, landfill space, and air and water pollution as well as a reduction in fuel-based chemical manufacturing processes since RAP does not require quarrying or mining operations compared to producing virgin aggregates. RAP has improved stiffness with expectations for a decrease in the probability of any cracking, thus fewer repairs and maintenance needs. This is an environmental gain if the outcomes for increased durability and longevity must be achieved.

In other words, if recycled pavements perform, it will be good for the environment. This is one of many reasons why OAPC is committed to advancing the responsible use of RAP. We are committed to continuing advocacy and dialogue with both provincial and municipal road owners to specify higher percentages of RAP in hot mix asphalt, and/or optimize

38 OA P C | ASP H A LTOP IC S

its use with proven processes such as WMA technology, including other innovative applications where possible.

This commitment extends to industry playing a vital role, with leadership and support from the council.

Through our collaboration with Good Roads, the Municipal Engineers Association (MEA), and the Centre for Pavement and Transportation Technology (CPATT) at the University of Waterloo, efforts have been made to obtain accurate data on RAP practices, stockpiles, quantities, and locations in Ontario to be able to better monitor and evaluate the effects of current practices and specification on the lifecycle of recycled pavements. You may revisit details of the 2022 Ontario RAP Report on the OAPC website. A 2023 Ontario RAP Report should be available before the year wraps up.

The Ontario Asphalt Expert Task Group (OAETG) has also investigated and produced a report on international experiences with high RAP content mixtures. The report reviewed several jurisdictions and presented commonalities in approaches, with suggestions for a route forward for Ontario to achieve similar outcomes. The report is available on the OAPC website.

Further to OAPC’s commitment to advancing RAP use, we intend to turn the attention to characterizing the stockpiles across Ontario’s three Performance Graded Asphalt

Cement (PGAC) zones. The intent is to collect processed RAP samples from stockpiles to determine their true grade. It is an essential and current practice that stockpiled RAP is tested and the characteristics of the RAP are clearly defined so that an appropriate mix design can be developed.

The lessons learned from these collaborative efforts and initiatives will provide an additional tool to both the industry and road owners to achieve reduction targets in carbon emissions, and OAPC is committed to this goal by advancing the responsible use of RAP.

The grade of virgin PGAC is determined by the RAP quality and content of the mix and the design temperature required for the recycled mix. In Ontario, we have traditionally used between 15 per cent (OPSS-MUNI) and 20 per cent (OPSS-PROV) as the level of RAP where a grade change is required. These limits were set in the early 2000s and were based on older RAP that contained penetration-based binders that were potentially stiffer than what may be found in current RAP stockpiles. Also, given some municipal concerns with using RAP, the industry agrees that the level of RAP where the grade needs to be changed should be re-evaluated. The outcome could influence the revision of recommended quantities for RAP use, as well as PGAC bumping requirements across Ontario’s three PGAC zones and for different traffic configurations.

Another important collaborative stride in OAPC’s commitment to advancing RAP use is our recent partnership and funding support for Transportation Association of Canada (TAC) new project to study the use of RAP in asphalt mixtures. This project is in response to concerns of premature distresses particularly prevalent in mixtures with higher amounts of RAP. The project would develop a practiceready guideline on the use of RAP in asphalt mixtures that can be applied immediately by Canadian transportation agencies. The guideline would be based on effective agency practices and input from industry leaders, and would address material management, mixture design, plant production, and laydown of asphalt mixes produced with RAP to ensure proper performance.

FA L L 20 23 39

Thank you TO THE 2023 OAPC

FALL ASPHALT SEMINAR SPONSORS.

OAPC FALL ASPHALT SEMINAR – NOVEMBER 30, 2023 WOAPC’s Fall Asphalt Seminar, Advancing with the Times: People and Processes in Asphalt Technology, promises to shed light on the evolving landscape of asphalt technology. In addition to our exciting presentations, we’re hosting a tradeshow for businesses to showcase their products, services, and innovations. $15 from each registration will be donated the Asphalt Research Fund.

Join us on November 30 by emailing Jasvinder Singh at Jasvinder.singh@orba.ca.

NOMINATE A DESERVING

INDIVIDUAL FOR AN OAPC AWARD! DEADLINE

NOV 30!

Let’s recognize and celebrate those who embody the spirit of our industry. Nominate today!

• H ONORARY LIFE MEMBERSHIP AWARD

recognizing long-term dedication to OAPC’s objectives.

OAPC AT SWIFT Our amazing Technical Services Director, Doubra Ambaiowei, was invited to present and participate in a panel discussion at the Canadian Airfield Pavement Technical Group Workshop during the 2023 Summer Winter Integrated Field Airfield Technologies (SWIFT) conference in Winnipeg. We are always thrilled to have our team join forces with industry leaders from the Cement Association of Canada and WSP in Canada to promote innovations in pavement sustainability.

• K ING BEAMISH EXCELLENCE AWARD acknowledging voluntary contributions and leadership in OAPC.

• E ARL KEE VOLUNTEER OF THE YEAR AWARD saluting exemplary voluntary contributions in the past year.

• J OE BUNTING MENTORSHIP AWARD

highlighting those who inspire and nurture the industry’s future leaders.

The nomination process is straightforward and doesn’t take long. More details for each award can be found in the OAPC Award Brochure.

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L-R: Tim Smith, Cement Association of Canada, Doubra Ambaiowei, ORBA/OAPC, and Maeri Machado, WSP in Canada.

2023 OAPC ASPHALT TECHNICAL SYMPOSIUM We thank everyone who made this year’s OAPC Asphalt Technical Symposium a success. The event, which took place at MTO’s Centre for Excellence in Transportation Infrastructure (CETI), kicked-off with a series of presentations on industry challenges and opportunities followed by a tour of MTO’s new lab facility.

Lastly, we would like to thank our 2023 sponsors!

PRESENTING SPONSOR

SESSIONS SPONSORS

SEVENTH ANNUAL MUNICIPAL PAVING AWARD The Municipal Pavement Awards recognize successful municipal-private sector collaborations in hot mix asphalt road construction in Ontario. All hot mix paving projects completed between January 1, 2023 and November 30, 2023 are eligible. To nominate a project, complete the application form on the Goad Roads site and provide supporting documentation no later than December 29, 2023.

DEADLINE DECEMBER 23, 2023

OAPC CHAIR’S DINNER NOVEMBER 29

OAPC AT TAC The Transportation Association of Canada (TAC) and local conference hosts, Transport Canada and the Ontario Ministry of Transportation, hosted the 2023 TAC Conference & Exhibition, September 24 to 27 in Ottawa and OAPC was there. Doubra Ambaiowei, Technical Services Director, presented a recap of the O-MAP Round 1 Performance Testing Study, an initiative commissioned by OAPC. Our coverage accentuated measures to bridge gaps in understanding in performance testing methods and acceptance, spotlighting the quality assurance processes for performance acceptance.

Scan to see all of our events!

OAPC FALL ASPHALT SEMINAR NOVEMBER 30

ORBA CONVENTION FEBRUARY 4 to 6, 2024

ORBA ROAD BUILDING ACADEMY FEBRUARY 27 to MARCH 1, 2024

FA L L 20 23 41

THE LAST WORD Taylor Lefebre

Innovation and leadership for award win

by Lara Henry

The asphalt industry’s commitment and passion to continuous improvement and innovation is well known to insiders, so it’s particularly heartening when one of our own gets the outside recognition they deserve.

Taylor Lefebre, Director, Quality and Production, Eastern Canada, at Green Infrastructure Partners Inc. (GIP), recently won the 40 Under 40 award in Canadian Construction by SitePartners and On-Site Magazine.

When describing their decision, SitePartners says this about Lefebre’s award: “The many reasons for Taylor Lefebre to stand out in Canada’s construction industry include his pioneering efforts in design, production and paving methods that produce higher quality at lower costs, reduced energy consumption and lessened environmental impacts. He has shared some of his breakthroughs not just with colleagues, but also as an award-winning technical author and presenter.

looking for ways to optimize the product or improve the process.

“Taylor is a model of the approach that sustainable operations is the responsibility of the entire organization.

His tireless efforts to improve the performance, resiliency and circularity of our products benefits our customers and the sustainability of GIP — and shows what kind of leader he is,” says Mac Carmichael, Senior Director, Sustainability and Environment, at GIP. However, of all the things he’s done, Lefebre says he’s most proud of his role in developing people. “Everyone in the industry has seen the issues with attracting and keeping people, and the knowledge gap between entry-level and senior people. I’ve worked really hard to create mid-level roles and train people for those roles. It’s important for people to have that avenue for growth and career development, and it benefits us as a company and as an industry,” says Lefebre.

Winners of the 40 Under 40 award are chosen by a panel of judges based on professional achievements, innovation, leadership and community involvement.

The organizers believe that highlighting the stories of young construction leaders is key to attracting more young people to the sector.

He is an avid participant in industry associations. He works with clients and suppliers alike to keep improving materials and processes, has personally developed software to improve quality control, and has had his innovations earn several accolades for his employer. And he is far from finished. Having entered management in 2017 at just 25 years of age, Taylor now instils the same drive for excellence in members of all his teams, including dozens of entry-level hires he has moulded into intermediate and even senior roles.”

“I’m so honoured to be recognized by this award. Thank you to everyone who has been a part of this journey, from GIP to those great companies and individuals where we have had the pleasure to build great infrastructure together. Let’s continue to build a brighter future for Canadian construction,” says Lefebre.

Lefebre started at the Coco Group (now GIP) in 2014, and recently became director of quality and production in May 2023. While Lefebre considers his core responsibility to be ensuring every job is done right and to the owner’s specifications, he never stops

Lara Henry is a communication specialist and editor of ASPHALTopics.

42 OA P C | ASP H A LTOP IC S