Comparative study of compressive behavior of confined NSC and UHPC/UHPFRC cylinders externally wrapped with CFRP jacket

Abstract

This study conducted a fundamental investigation on compressive behaviors of carbon fiber-reinforced polymer (CFRP)-confined normal-strength concrete (NSC) and ultra-high performance concrete (UHPC)/ultra-high performance fiber-reinforced concrete (UHPFRC) subjected to concentric axial loading. The mechanical behavior of confined UHPC/UHPFRC, such as the failure mode, stress-strain response, and lateral dilation behavior, was found different from that of confined NSC. Specifically, the passive confining behavior of UHPC/UHPFRC was distinguished from NSC in terms of concrete crack evolution. Diverse cracking propagation patterns resulted in distinct dilation ratios and CFRP efficiency factors. The CFRP confinement could delay the formation of shear cracks, resulting in a linear increasing stage of the first branch in the stress-strain curve of CFRP-confined UHPC/UHPFRC. Moreover, existing stress-strain models available for CFRP-confined UHPC/UHPFRC were profoundly evaluated in this study.