Experimental investigation of ecc jackets for repair of pre-damaged r.C. members under monotonic loading

Abstract

With the advent of strain-hardening cementitious composites (SHCC), an opportunity for alternative jacketing solutions is presented, where the internal confinement exerted by the fibers in the material may effectively encase the structural component, thereby enhancing the strength and deformation capacity in the critical regions. This concept is explored in the present paper through testing of four pre-damaged prismatic flexural reinforced concrete members with various reinforcing deficiencies. Thin SHCC jackets constituted of a fiber-reinforced Engineered Cementitious Composite (ECC) are used to replace the damaged cover without any additional confining reinforcement. An advantage of cover replacement is that strengthening is achieved without altering the dimensions of the members. The experimental results documented the SHCC jackets’ effectiveness as a rehabilitation strategy, enhancing both the strength and ductility of the retrofitted elements and mitigating the deficiency in transverse reinforcement detailing. The strength recovery showed that the cover-thin SHCC jacket sufficed to enhance flexural and shear resistance through confinement and mobilization of stress transfer at the interface with the encased core.