Experimental Research on the Behavior and Crack-Sealing Capability of Masonry Mortars Reinforced with PVA Fibers

The durability of cementitious materials is essential for the development of sustainable construction, and the integration of self-healing mechanisms can reduce damage and maintenance costs. This paper analyzes the self-healing capacity of masonry mortars reinforced with polyvinyl alcohol (PVA) fibers and crystalline additives, when exposed to repeated wet-dry cycles. Four mortar mixtures were investigated, including two control mixtures and two mixtures modified with self-healing agents. The experimental program included determination of density, water absorption, compressive strength, and flexural strength, as well as monitoring the evolution of microcracks during the healing process. The results showed that modified mortars exhibited complete surface crack sealing under the applied wet-dry conditioning regime, including an initial crack width of 346 μm, which was completely sealed within 48 h. The observed crack-sealing behavior may result from the combined contribution of autogenous healing processes, PVA-fiber crack bridging, and the crystalline admixture; however, their individual contributions and possible synergistic effects cannot be distinguished from the present experimental design. The results indicate the potential of the investigated modified mortars to improve crack-sealing performance and contribute to enhanced durability. However, no direct environmental or life-cycle assessment was performed in the present study; therefore, potential sustainability benefits associated with service-life extension and reduced repair demand require further quantitative assessment.