Self healing of concrete structures - Novel approach using porous network concrete

Abstract

To repair concrete cracks in difficult or dangerous conditions such as underground structures or hazardous liquid containers, self healing mechanism is a promising alternative method. This research aims to imitate the bone self healing process by putting porous concrete internally in the concrete structure to create a porous network similar to 'spongious bone'. When cracks are formed and detected by sensors, healing agent can be infused into the porous network so as to fill up voids and seal a crack or cracks in the concrete body. This idea was tested using cylindrical and beam samples. A porous concrete core was placed in the concrete specimens. Uniaxial tensile load in the case of the cylindrical samples and bending load in case of beams was applied to create cracks. A healing action was performed by injecting healing agent manually. The results show that a macro-crack is sealed and strength of concrete is regained. Therefore, the concept is considered as to be feasible for self repair mechanism in concrete. © 2012 Japan Concrete Institute.