Autogenous healing of engineered cementitious composites under wet-dry cycles

Self-healing of Engineered Cementitious Composites (ECC) subjected to two different cyclic wetting and drying regimes was investigated in this paper. To quantify self-healing, resonant frequency measurements were conducted throughout wetting-drying cycles followed by uniaxial tensile testing of self-healing ECC specimens. Through self-healing, crack-damaged ECC recovered 76% to 100% of its initial resonant frequency value and attained a distinct rebound in stiffness. Even for specimens deliberately pre-damaged with microcracks by loading up to 3% tensile strain, the tensile strain capacity after self-healing recovered close to 100% that of virgin specimens without any preloading. Also, the effects of temperature during wetting-drying cycles led to an increase in the ultimate strength but a slight decrease in the tensile strain capacity of rehealed pre-damaged specimens. This paper describes the experimental investigations and presents the data that confirm reasonably robust autogenous healing of ECC in commonly encountered environments for many types of infrastructure. (C) 2009 Elsevier Ltd. All rights reserved