Enhancing long-term tensile performance of Engineered Cementitious Composites (ECC) using sustainable artificial geopolymer aggregates

Artificial geopolymer aggregate is an emerging technology in the field of solid waste recycling, aiming to ease the exploitation of natural aggregates as well as reduce the environmental burden of industrial/urban/agricultural waste and by-product accumulations. In this study, geopolymer aggregates (GPA) were strategically utilized to enhance long-term tensile performance and sustainability of high-strength Engineered Cementitious Composites (ECC). Accelerated aging test was conducted to evaluate the long-term performance of GPA-ECC, with the conventional fine silica sand ECC (FSS-ECC) as the control group. It was found that after accelerated aging (i.e., to simulate long-term curing condition), the compressive and tensile strengths of both GPA-ECC and FSS-ECC increased. In addition, owing to the flaw effect of GPA, the long-term tensile ductility of GPA-ECC was maintained, while that of FSS-ECC decreased significantly. Compared with FSS-ECC, GPA-ECC showed better multiple cracking behavior, higher strain energy density, and finer crack width under both short- and long-term conditions. Finally, a cost analysis of ECC matrix was conducted to exhibit the cost-efficiency and sustainability of GPA-ECC. This study provides a sustainable approach for enhancing the long-term tensile performance of high-strength ECC based on artificial aggregates.