In a significant stride towards sustainable construction, researchers have unveiled promising findings on the use of geopolymer stabilized recycled materials for pavement infrastructure. The study, led by Dulanja Dayaratne from the Department of Civil and Construction Engineering at Swinburne University of Technology in Australia, explores the potential of recycled concrete aggregate (RCA) and recycled glass (RG) blends in creating low-carbon pavement materials.
The research, published in *Materials Today Sustainability* (which translates to *Materials Today for Sustainable Development*), addresses the growing demand for eco-friendly construction practices. Traditional cementitious binders are being challenged by engineered geopolymer binders, which offer reduced carbon emissions without compromising mechanical properties.
Dayaratne and his team investigated the effects of varying RCA/RG proportions, precursor types, and dosages, as well as different curing regimes on the performance of geopolymer stabilized mixtures. Their findings revealed that while increasing the RG content led to a decrease in the strength of the mixtures, higher precursor dosages generally resulted in improved unconfined compressive strength (UCS) values.
“Our study demonstrated that fly ash (FA) geopolymer stabilized mixtures had lower UCS compared to those stabilized with slag (S) or a binary precursor of FA and S,” Dayaratne explained. “Most notably, the majority of S and (FA+S) geopolymer stabilized mixtures met the minimum UCS requirement of 3 MPa stipulated by local road authorities, except for a few mixtures with a 5% precursor dosage.”
The research also highlighted the critical role of curing time and temperature in the strength development of these mixtures. Repeated loaded triaxial (RLT) and four-point bending tests further showed that the addition of RG decreased the resilient modulus and fatigue performance of the geopolymer stabilized mixtures.
Despite these challenges, the study underscores the potential of geopolymer stabilized RCA/RG mixtures as greener alternatives for pavement construction. “This research opens up new avenues for the construction industry to adopt more sustainable practices by utilizing recycled materials and geopolymer binders,” Dayaratne noted.
The commercial implications for the energy sector are substantial. As the push for sustainability intensifies, the development of low-carbon materials for infrastructure projects could lead to significant reductions in carbon emissions. This, in turn, could drive innovation and investment in green technologies and materials, fostering a more sustainable future for the construction industry.
The findings of this study not only contribute to the body of knowledge on sustainable construction materials but also pave the way for future research and development in the field. As the industry continues to evolve, the integration of recycled materials and geopolymer binders could become a standard practice, shaping the future of pavement geotechnics and ground improvement.