Design and performance of cost-effective green engineered cementitious composites with low drying shrinkage and self-healing

Despite its excellent mechanical properties and crack control ability, engineered cementitious composite (ECC) was still facing challenges such as high cost, high carbon footprint, high shrinkage, and insufficient self-healing ability in natural environments for engineering applications. This study designed and developed a new ECC with characteristics of low-cost, green, ultra-high ductility, low drying shrinkage and self-healing. The effects of superabsorbent polymer (SAP) and light-burned magnesia oxide (LB-MgO) on the micro and macro mechanical properties of ECC were studied; the self-healing performance evaluation system of ECC in natural environment was established; the shrinkage regulation mechanism of SAP and LB-MgO on ECC was revealed; the microstructure, pore structure and hydration mechanism were analyzed. The study showed that the addition of SAP and LB-MgO can effectively reduce the fracture toughness and shrinkage of the matrix, improve the strain hardening strength index and energy index of ECC, and obtain the self-healing ability in the natural environment, which can continue to maintain its durability. This kind of ECC helps improve the long-term durability of the structure and meets high performance requirements while reducing material costs and environmental impact effectively.