An overview of the design approach to strengthen existing reinforced concrete structures with SRG

The civil engineering community is acquainted with the fact that existing reinforced concrete structures require constant maintenance in order to increase their service life. Nevertheless, maintenance might be not sufficient when a change of use, which entails for an increase of the service loads, damage due to aggressive environment, or the need of withstanding natural and man-made hazards were not taken into account when the structure was designed. Fiber-reinforced composites are a suitable tool to strengthen and thus increase the capacity of the structural element without changing the original configuration and adding mass. Steel reinforced grout (SRG) is a relatively new tool in the realm of fiber-reinforced composites that consists of steel fibers embedded in a cementitious mortar. This paper presents a state-of-the art on SRG that includes a literature review and points out the effectiveness of SRG for flexural strengthening and confinement of concrete members. It also proposes a design approach to strengthen reinforced concrete beams based on the available data on flexural tests on beams, bond tests on SRG-concrete joints, and tensile tests on SRG coupons