Rethinking Asphalt: The Quest for Sustainability in Roadway Construction
Beneath the opaque surface of asphalt pavement lies one of the most complex and sustainable materials in our modern infrastructure. Asphalt isn't just a material for paving roads; it's a key player in the quest for greener, more sustainable construction practices.
Sustainability in Asphalt
Sustainability in the asphalt industry revolves around reducing carbon emissions and extending the lifespan of roadways. We can achieve this by using low-carbon materials, improving durability, and incorporating renewable additives. For example, integrating bio-oils — by-products of the agriculture industry — into asphalt mixes helps soften asphalt allowing for increased use of recycled asphalt pavement (RAP) and lowers the carbon footprint of asphalt production processes.
Innovative Projects Lead the Way
Plastic Bags in Roadways
One groundbreaking approach involves incorporating shredded plastic bags into asphalt mixtures. - Trial mixtures have shown the potential to enhance strength and crack resistance. BATT was involved with a project alongside Mago Construction and GreenMantra® Technologies that incorporated the equivalent of one million Walmart plastic (low density plastic) bags into a mile of asphalt pavement. If we can put waste materials into roads without hurting the road service life, why wouldn’t we? While more work is needed in this area, we have potential to help reduce and reuse certain plastics. NCAT test track currently has several trials in place.
Tire Rubber in Roadways
Tire rubber, when recycled and blended into asphalt, significantly improves the durability of roadways. Rubberized asphalt in open graded mixes can also improve skid resistance and lower road noise, leading to safer and better driving conditions. BATT has been involved with testing rubber modified asphalt for projects through the Rubber-Modified Asphalt (RMA) program in Kentucky. Using tire rubber in asphalt helps address the issue of tire waste, which is a growing environmental concern. By recycling old tires, we not only reduce landfill waste but also give these materials a new purpose, thus contributing to a circular economy. While asphalt pavements should not be the target of a linear landfill option, pavements can help reduce some of the waste.
Soybean and Corn Oil Additives
Additives made from soybean and corn oil can enhance the flexibility, durability, and crack resistance of asphalt pavements. These oils show promise to also reduce the aging effect, which ultimately helps pavements to crack less. Bio-oils are renewable and help decrease the carbon footprint. Colorbiotics® is a company that is changing the way asphalt pavements are made and what they are made with. Using their products showcases how blending bio-oils with recycled asphalt pavement (RAP) can be both effective and eco-friendly. Bio-oils are also easy to blend, safe to use, and most have a low odor. These are benefits to both the lab and field.
Longer-Lasting Roads: A Sustainable Solution
Reducing the frequency of road repairs and construction cycles is another crucial aspect of sustainability. By making roadways last longer, we reduce the need for repeated construction activities, which in turn lowers overall carbon emissions. Using polymers and fibers, such as those from Kraton™ and Surface Tech™, can significantly extend pavement life and improve performance. Surface Tech’s ACE XP was among the first additives to earn an Environmental Product Declaration (EPD), plus show a quick return on investment to reduce cracking.
Taking Action
So, what can be done right now? The answer lies in two key actions: 1) using materials that enhance the longevity of our roadways and, 2) increasing the use of RAP. These practices not only contribute to a more sustainable industry but also pave the way for a future where our infrastructure supports environmental goals.
By embracing these innovations and focusing on durability, the asphalt industry can transform from a traditional construction method into a model of sustainability. At BATT, we support the efforts and advancements that drive the change toward sustainable roads, one project at a time.
For more information on the lab and field services provided by BATT, visit us online.
