Nonlinear numerical simulation and experimental verification of bondline strength of CFRP strips embedded in concrete for NSM strengthening applications

This article presents results of an investigation that focuses on assessing bondline strength of carbon/epoxy fiber reinforced polymeric (CFRP) precured strips embedded in concrete for near-surface-mounting (NSM) strengthening applications. In this study, experimental evaluation and nonlinear numerical analysis of CFRP/concrete interfacial bond behavior are investigated. In this study, 15 pull-out tests were performed on different reinforced concrete (RC) U-shaped column specimens with different NSM groove configurations to evaluate the effect of groove size, groove depth, and adhesive bondline thickness on overall performance of the CFRP-NSM system and to identify the optimum groove dimensions. Experimental results indicated that changing groove geometries of the NSM-FRP reinforcements significantly affect bondline strength and associated mode of failures of NSM-CFRP system. It was also shown that increasing bondline length lead to an increase in ultimate failure load and CFRP rupture strain. Based on results of this study, NSM materials with lower longitudinal moduli and higher rupture strains (e.g., E-glass/epoxy or basalt/epoxy), may increase toughness and enhance performance of the NSM strengthening system.

Automated summary

This study focuses on assessing the bondline strength of carbon/epoxy fiber reinforced polymeric (CFRP) precured strips embedded in concrete for near-surface-mounting (NSM) applications. Experimental and numerical analysis were conducted to evaluate the interfacial bond behavior. Results showed that changing the groove geometries significantly affect the bondline strength of the NSM-CFRP system, and increasing bondline length leads to higher failure load and CFRP rupture strain.