Self-healing of PE-fiber reinforced lightweight high-strength engineered cementitious composite

High-strength engineered cementitious composite (HS-ECC) reinforced with polyethylene (PE) fiber typically features larger crack width compared with conventional polyvinyl alcohol fiber-reinforced engineered cementitious composite (PVA-ECC), diminishing the self-healing potential of HS-ECC. This larger crack width is attributed to the high matrix fracture toughness and the weak interfacial property between PE fiber and matrix. In this study, synergistic utilization of crumb rubber (CR) and hollow fly ash cenosphere (FAC) particles as lightweight particles and artificial flaws were employed to reduce the density, the matrix toughness, and the crack width of HS-ECC, leading to a lightweight HS-ECC (LWHS-ECC) with enhanced self-healing capability. The impacts of CR and FAC particles on the density, mechanical, and self-healing properties of LWHS-ECC were investigated. The addition of these two particle types significantly narrows the crack width from 120 μm to 50 μm and promotes the self-healing property of LWHS-ECC. Despite lower compressive and tensile strengths with an increasing amount of CR and FAC, the tensile strength to self-weight ratio of LWHS-ECC is twice that of M45 PVA-ECC. The realization of the self-healing ability of PE-fiber reinforced LWHS-ECC is expected to enlarge its practical application.