Self-healing behavior of concrete cracks

摘要

Usually considered an extremely common phenomenon, not leading directly to sudden failure, cracking is the main risk factor for the general problem of concrete durability. The cracks are access paths for aggressive agents, generating reinforcement corrosion, strength reduction, spalling of the concrete cover and other damage forms. In the context of multiple new solutions for concrete manufacturing, utilization and compositions, rapidly developed in the latest years, cracking control is still difficult to ensure. An indirect possibility is "healing" cracks by inducing self-healing concrete mechanisms: further hydration of the unreacted cement determining crystallization of calcium carbonate along the crack, swelling of cement hydration products, cracks closed by small concrete particles and even mechanical properties regaining: compressive and tensile strength, dynamic modulus of elasticity. The aim of this paper is to present the effective self-healing potential of cementitious materials as a possible and accessible way for considerable deterioration rate reduction.