Effects of Curing Conditions and Supplementary Cementitious Materials on Autogenous Self-Healing of Early Age Cracks in Cement Mortar

The autogenous healing potential of cement-based materials is affected by multiple factors, such as mix composition, crack width, pre-cracking age and external environmental conditions. In this study, the effects curing conditions supplementary cementitious (SCMs) on self-healing early cracks in cement mortar were investigated. Three conditions, i.e., standard curing, wet–dry cycles incubated water, two SCMs, fly ash (FA) blast furnace slag (BFS) with various contents (cement replacement ratio at 0%, 20%, 40%) examined. A single (pre-cracking 3 days) a width 200~300 ?m was generated cylindrical specimens. Autogenous efficiency specimens evaluated performing visual observation water permeability test. Moreover, microstructure analysis (XRD, SEM TG/DTG) utilized to characterize products. results indicated that presence essential for mortar. highest water. However, no significant occurred exposed curing. For cycles, longer time needed obtain good compared samples SCMs type content significantly ability cracks. decreased increases FA BFS content. mortars exhibited greater recovery relation penetration resistance reference mortars. Almost same regain tightness lower crack-healing after 28 days observed reference. major product surface without micron-sized calcite crystals typical rhombohedral morphology.