Reliable concrete repair

Abstract

This paper highlights the importance of achieving durable and long-term predictable repair of reinforced concrete structures. The performance of concrete repair in past and current engineering practice, including all types of repair and application of different materials, is often unsatisfactory. One of the reasons for this lays in the fact that knowledge regarding bonding mechanism and bond properties at the interface of repair material and concrete substrate is still lacking. This paper intends to give a critical review on the parameters which have to be taken into account when designing appropriate connection between concrete substrate and new repair material. What is more important than achieving a strong bond between overlay and concrete substrate, is reaching monolithic behaviour which should ensure an even distribution of stresses and uniform load transfer in the repaired structure. As a consequence, this paper does not emphasize just tensile strength of bond, which is in literature often stated as a fundamental issue, but also other important matters for controlling debonding mechanism in concrete repairs. One of the promising repair materials which has been developed recently is Engineered Cementitious Composite. Therefore, application of this material is additionally overviewed.