Application of a trilinear bond-slip model to FRCM-concrete joints

This study presents an analytical approach for predicting the load-slip response of fiber reinforced cementitious matrix (FRCM)-concrete joints. The FRCM-concrete interfacial behavior was described with a trilinear cohesive material law consisting of a linear stage, a softening stage, and a friction stage. Accordingly, provided that the bonded length is longer than the composite effective bond length, the full-range applied load-global slip response consists of five stages: an elastic stage, an elastic-softening stage, an elastic-softening-debonding stage, a softening-debonding stage, and finally a fully debonded stage. Closed-form solutions for the applied load-global slip, interfacial shear stress distribution, and longitudinal stress distribution along the composite bonded length were derived. Also, the debonding load, peak load, and the effective bond length were analytically obtained. Results of the analytical model were compared to experimental results of six single-lap shear specimens instrumented with strain gauges mounted to the longitudinal fibers along the composite bonded length.