Self-healing performance of coated slag aggregates in wheat straw ash blended cement composites

Abstract

The cracks in the concrete structures permit the ingress of harmful ions which ultimately exacerbate the durability of the structures. In addition, the environmental concern of the cement production necessitates the utilization of pozzolanic materials. This study used wheat straw ash as cement replacement material. Sodium silicate impregnated in slag aggregate, an industrial by-product, was used as the self-healing agent. The impregnated slag aggregates were coated and used as a sand replacement. Mortar samples were analyzed for compressive strength. Self-healing performance of the mortar samples was investigated via ultrasonic pulse velocity, water permeability, and dynamic modulus of elasticity tests. The results demonstrate that the addition of coated slag aggregate significantly enhanced the self-healing performance of the mortar samples. Additionally, the incorporation of wheat straw ash resulted in an increased rate of crack filling.