Save on Costs with RAP Use By Vince Aurilio
Editor’s Note: The National Asphalt Pavement Association (NAPA) recently released the 15th Annual Asphalt Pavement Industry Survey on Recycled Materials and Warm-Mix Asphalt Usage (IS-138) with results from the 2024 construction season showing over 96% of asphalt mix that’s reclaimed from old asphalt pavements is put back to use in new asphalt pavements, and the remaining 4% is used in other civil engineering applications. These stats and facts make Sripath Technologies’ information relevant for all sectors of the asphalt industry. his article explores the financial incentives of incorporating reclaimed asphalt pavement (RAP) into asphalt mixtures and highlights how technologies like asphalt rejuvenators unlock even greater economic gains.
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Quick Refresher: Why RAP Matters RAP refers to asphalt material recovered from road surfaces that have been milled or demolished during maintenance or reconstruction. The material consists of high-quality aggregates coated with aged asphalt binder, which is an asset that can be reused in new pavement mixes. Rather than sending these valuable resources to landfills, RAP can be processed and blended back into hot-mix asphalt (HMA) or warm-mix asphalt (WMA) production, replacing portions of virgin aggregates and bitumen. The growing push toward sustainability has elevated RAP’s importance. By reusing existing materials, producers can reduce dependence on newly quarried stone and petroleum-based binders while simultaneously reducing greenhouse gas emissions and landfill use. However, because the binder in RAP has aged and stiffened through oxidation, it does not always perform identically to virgin binder. That’s where asphalt rejuvenators (or recycling agents), which are additives designed to restore some of the original flexibility and performance of aged binders, are essential. RAP offers: • Direct material cost savings • Lower transportation and logistics costs • Reduced disposal and landfill costs Case Study: How ReLIXER® Enabled Cost Savings in High-RAP Mix One of the most effective ways to unlock the economic benefits of RAP is with asphalt rejuvenators designed to restore balance to aged binder systems. A recent comparison between a conventional control mix and a high-RAP mix incorporating ReLIXER asphalt rejuvenator illustrated how rejuvenation can reduce overall mix costs while maintaining performance expectations. In the control mix, RAP content was limited to approximately 15%, with the majority of the blend relying on virgin aggregate and virgin binder. Virgin binder alone accounted for roughly 5.5% of the total mix composition, contributing disproportionately to material costs. (This low-RAP, non-rejuvenated approach represents the traditional baseline for many producers but comes with higher exposure to raw material pricing risk.) 36 SPRING 2026
RAP stockpile creation courtesy of Mills Construction, Austin, Texas, and Powerscreen Texas, a Terex Company
By contrast, the high-RAP mix incorporating ReLIXER increased RAP content to 40%, significantly displacing both virgin aggregate and virgin binder. In this formulation, virgin binder usage was reduced to approximately 3.8%, while ReLIXER was added at a very small dosage, about 0.1% of the total mix. Despite this minimal addition rate, the rejuvenator played a critical role in restoring workability and performance balance to the aged RAP binder, allowing higher recycled content without compromising mix design requirements. From a cost perspective, the impact is clear. When indexed against the control mix (set at 1.00), the high-RAP mix with ReLIXER achieved a cost index of approximately 0.85, representing a meaningful reduction in overall material costs. These savings were driven primarily by reduced reliance on virgin binder and aggregate. Importantly, the cost reduction was not achieved by sacrificing durability. Rejuvenation enables producers to design high-RAP mixes that meet performance expectations while improving economic efficiency. Over time, this approach also supports longer-term value through improved resistance to premature cracking, better aging characteristics, and reduced maintenance demands, further extending the cost benefits beyond initial production. In the evolving landscape of asphalt production, RAP stands out as a cost-effective and sustainable solution to rising material costs and environmental pressures. By reducing reliance on virgin aggregates and bitumen, lowering transportation and disposal expenses, and delivering durable pavement performance, RAP helps producers and project owners stretch budgets further while meeting quality and sustainability goals. With proper mix design strategies including a rejuvenator to optimize performance, RAP use is more than a cost-saving tactic. It is a pathway toward smarter, greener infrastructure development and maintenance. For more information, contact info@sripath.com