Assessing the efficiency of pre-soaked expanded perlite usage incorporation on the self-healing ability of cementitious composites

Usage of Pre-Soaked Expanded Perlite Aggregate (PS-EPA) as an internal curing material in the production of cementitious based composites has been shown to an influential method of counteracting autogenous shrinkage and therefore early-age cracking. These beneficial effects of PS-EPA usage evoke that the use of PS-EPA as internal water reservoirs may also promote the self-healing ability of cracks in cementitious composites. This study assesses the efficiency of the PS-EPA usage on the self-healing of cementitious composites. For this purpose, PS-EPA was replaced with the aggregate used in cementitious composites at different replacement rates. Cementitious composite specimens with or without PS-EPA were stored in water up to 28 days, and then mechanical loading was applied to generate deterioration on the specimens. At the age of 28 days, pre-loaded and sound specimens exposed to continuous air exposures for a month. The degree of deterioration as result of mechanical pre-loading and the degree of self-healing were determined by the characterization of crack numbers and widths, transport (chloride ion permeability) and mechanical properties (splitting tensile strength), and compared with the specimens without PS-EPA. Test results revealed that mechanical properties, crack widths and numbers, and chloride ion permeability of specimens were significantly improved with the increase of PS-EPA content while enhanced further hydration and healing capability of specimens under the continuous air exposure after pre-loading.