In the quest for sustainable construction materials, researchers have been exploring alternatives to traditional hot mix asphalt (HMA), which, despite its widespread use, comes with significant environmental drawbacks. A recent study published in *Cleaner Materials* (which translates to *更清洁的材料* in Chinese) sheds light on the potential of cold mix binders, offering a greener approach to paving that could reshape the energy sector’s landscape.
Led by Rui Li from the National & Local Joint Engineering Research Center of Transportation and Civil Engineering Materials at Chongqing Jiaotong University, the research delves into the mechanisms and applications of three types of cold binders: conventional bitumen emulsions, and the emerging epoxy resin and polyurethane. These binders promise to reduce energy consumption and hazardous emissions by eliminating the need for high-temperature construction processes.
Bitumen emulsions, the most commonly used cold binder, have been a staple in surface dressing, tack coats, and cold mix applications. However, their performance falls short of HMA in terms of early strength and mechanical properties, limiting their use in structural layers. To bridge this gap, researchers have turned to polymer latexes like SBR latex and waterborne epoxy resin as modifiers. “The incorporation of polymer latexes can significantly enhance the performance of bitumen emulsion, improving high- and low-temperature performance, adhesion with aggregate, and fatigue performance,” explains Li.
The study also highlights the potential of polymer binders like epoxy resin and polyurethane, which offer fast curing, remarkable mechanical strength, and strong adhesion. However, challenges such as limited workability, insufficient resistance to weathering, and high initial costs need to be addressed before these binders can be widely adopted.
The implications for the energy sector are substantial. As the world shifts towards sustainability, the demand for eco-friendly construction materials is on the rise. Cold mix binders not only reduce the carbon footprint of paving projects but also offer cost savings in the long run. “This research paves the way for future developments in pavement engineering, providing a comprehensive review of the constitutions, properties, applications, and pros and cons of these cleaner construction materials,” says Li.
As the industry continues to innovate, the insights from this study could drive the adoption of cold mix binders, transforming the way we build and maintain our infrastructure. The journey towards sustainable construction is underway, and cold mix binders are poised to play a pivotal role in this transition.