Extruded Cementitious Hollow Tubes For Healing Agent Delivery

A novel self-healing system for cement composites is proposed in this study. It is based on the use of extruded cementitious hollow tubes filled with a liquid healing agent to be added in cement composites during mixing. These tubular capsules were characterized in terms of flexural strength, liquid storage capability, mixing survival effectiveness and releasing ability upon crack formation. The suitability of a specific mono-component liquid healing agent – a sodium silicate solution – was also assessed. Finally, the self-healing effectiveness of the proposed system was verified using a three-point-bending procedure to induce crack formation on laboratory scale specimens and to evaluate their mechanical recovery after self-healing. Positive results were achieved, though further research is needed to reach a final optimization.