Use of encapsulated healing agents to limit water uptake through crackis in mortar

Crack formation is a common issue that leads to durability problems in concrete structures. Fluids containing aggressive substances can rapidly penetrate in the concrete matrix through the cracks and cause steel corrosion or deterioration of the concrete. In order to avoid major damage to the concrete structures, repair of cracks is in most cases necessary. Creating a self-healing cementitious material is a possible solution to avoid major repair works of concrete structures. In this research, autonomous healing of cracks by encapsulated healing agents was investigated to reduce water ingress through cracks in mortar. The two polymeric healing agents that were used in this study were able to reduce the water ingress through cracks. The low viscosity polyurethane created a complete and consistent crack healing, reducing the water absorption to values even lower than uncracked cementitious material. For the high viscosity polyurethane the results showed more scatter due to uncomplete crack healing for some specimens. The reduction of water ingress due to the incorporation of the self-healing mechanism has a positive effect on the durability of cementitious materials and hence can prolong the service life of concrete structures