Prediction of Self-Healing Potential of Cementitious Materials Incorporating Crystalline Admixture by Isothermal Calorimetry

Abstract

Crack formation is an inherent property of concrete structures; however, these materials also have the ability to heal cracks autogenously. External water penetrates the inside of concrete through the cracks, and unreacted cement particles present on the crack surface are rehydrated. Cracks are healed by hydration products owing to further hydration. Ground-granulated blast-furnace slag (GGBFS) and fly ash (FA) have slower reactions with water than cement. Because of this late reactivity, there is a high possibility of being present in an unreacted state inside the matrix. This study investigated the self-healing potential of supplementary cementitious materials (SCMs) such as GGBFS, FA, and calcium sulfur aluminate (CSA) expansion agents. For this purpose, isothermal calorimetry and water flow tests were performed. Experimental results showed that the self-healing potential of GGBFS and CSA expansion agent was higher than that of OPC and FA is decreased.