Self-healing efficiency of cementitious materials containing tubular capsules filled with healing agent

It has been estimated that, in Europe, 50% of the annual construction budget is spent on rehabilitation and repair of the existing structures [1]. Therefore, autonomous crack healing of concrete, a construction material that is highly susceptible to cracking, would be desirable. In this research, an encapsulated healing agent was embedded in the mortar matrix to obtain self-healing properties. Upon crack appearance, the capsules break and the healing agent is released, causing crack repair. By means of Computed Tomography and visual observation of the crack faces, filling of the cracks with healing agent was observed. It was seen that more than 50% of the original strength and stiffness could be regained after self-healing. It was also found that the water permeability could be reduced by a factor 102 to 104 due to autonomous crack healing. As a consequence, the proposed technique may be used for partial restoration of concrete properties after cracking.