Recent developments in Engineered/Strain-Hardening Cementitious Composites (ECC/SHCC) with high and ultra-high strength

Due to the excellent tensile strain-hardening and multiple-cracking behavior, Engineered Cementitious Composites (ECC), which are also known as Strain-Hardening Cementitious Composites (SHCC) or ultra-high-toughness cementitious composites (UHTCC), are attracting more and more attention from the research community of high-performance fiber-reinforced cementitious composites. Very recent efforts have been seen in the development of ECC with high/ultra-high compressive strength. This study aims to review the recent developments in high/ultra-high-strength ECC from material design to structural application, where two categories of this material are focused on: high-strength ECC (HS-ECC, 80–150 MPa in compression) and ultra-high-strength ECC (UHS-ECC, > 150 MPa in compression). All these two types of ECC have been developed based on the use of high-performance synthetic fibers [e.g., ultra-high-molecular-weight (UHMW) polyethylene (PE) fibers] and cementitious matrices with very dense microstructures. The reviewed mechanical properties of HS/UHS-ECC available in the literature include compressive strength, tensile strength and ductility, cracking behavior, dynamic performance, and fatigue behavior. The use of supplementary cementitious materials (e.g., slag, fly ash, and rice husk ash) and alternative aggregates (e.g., sea-sand and artificial aggregates) in the development of the green and high performance matrices for improved sustainability of HS/UHS-ECC is also summarized. The potential structural applications of HS/UHS-ECC and the future perspectives and challenges of HS/UHS-ECC are discussed.