Retrofitted Strength: Enhancing Reinforced Concrete with Rubber-FRP Jackets

The increasing demand to strengthen the aging reinforced concrete (RC) infrastructure and to address the issue of sustainability has resulted in the interest in fiber-reinforced polymer (FRP) retrofitting and rubberized concrete technologies. This paper discusses how the hybrid FRP systems (which use rubber particles or rubber layers) could be used to retrofit RC elements. Based on the recent findings on FRP-confined crumb-rubber concretes and rubberized concretes confined with glass FRP (GFRP), the study holds that the rubber-FRP systems can synergistically enhance the ductility, energy absorption and damage tolerance besides partially recycling the waste tire rubber. The outlined methodology involves the use of experimental testing of control RC specimens, conventionally FRP-wrapped specimens, and R-FRP wrapped specimens under both monotonic and cyclic loading. The discussion identifies observed trends in strength, stiffness and failure modes and interprets the trends as per the current models of FRP-retrofitted concrete members. These findings indicate that rubber-FRP retrofitting could provide a cost effective and sustainably viable alternative to seismic and impact critical applications before codified use.