Self-healing ability of cementitious composites: effect of addition of pre-soaked expanded perlite

Abstract

This study assessed the use of pre-soaked expanded perlite aggregate (PS-EPA) on the self-healing of cementitious composites by replacing a proportion of normal aggregate with PS-EPA at different replacement rates. Specimens with and without PS-EPA were stored in water for 28 d and then mechanical loading was applied to produce specimen deterioration. At the age of 28 d, pre-loaded and sound specimens were exposed to continuous air (CA) exposure for 30 d. The degree of deterioration as a result of mechanical pre-loading and the degree of self-healing were determined via characterisation of crack numbers and widths, transport (chloride ion permeability) and mechanical properties (splitting tensile strength), and specimens with and without PS-EPA were compared. The test results revealed that increased PS-EPA content significantly improved the compressive strength and chloride ion permeability of specimens, and that it further enhanced the hydration and healing capability of specimens under CA exposure after pre-loading.