Durable repair of aged infrastructures using trapping mechanism of engineered cementitious composites

Abstract

This paper introduces the concept of interface crack trapping and demonstrates experimentally the feasibility of this mechanism in a representative repaired concrete system. A microstructurally tailored Engineered Cementitious Composite (ECC) serving as the repair material was found to be most effective in trapping interface cracks such that typical failure modes in repaired systems, such as spalling or delamination, were prevented. It is shown that, for the same geometry and loading conditions, the ECC repair system is stronger, more ductile, more energy absorbing, and shows better crack width control in comparison with controlled systems with concrete or a typical fiber-reinforced concrete repair material. The trapping mechanism and the ECC repair material together represent a novel means to extend the service life of rehabilitated concrete structures.