Experimental and analytical study on bond strength of normal uncoated and epoxy-coated reinforcing bars

Abstract

Although a lot of experimental research has been carried out to study the bond behaviour of the epoxy-coated reinforcement, corresponding predictive analytical models are quite limited. In order to solve this problem, first, an experimental investigation on bond behaviour of normal uncoated bars and epoxy-coated bars with two nominal coating thicknesses was carried out; following, a bond model for predicting the bond strength of epoxy-coated reinforcing bar was proposed by taking into account epoxy coating thickness, bar parameters, friction coefficient of the epoxy-coated bar and concrete, crushed concrete friction coefficient, cover-bar diameter ratio and the embedded length of the bar. The proposed bond model was verified by previously published tests and current one of the authors. Based on the model verification and discussion, taking into account the effect of bar size, embedded length and epoxy coating thickness, the proposed bond model suggests values of the effective rib face angle for the normal uncoated and epoxy coated bars, respectively.