Modeling Bond Behavior of Lap-Spliced Enamel-Coated Rebar

Bond behavior of coated rebar spliced in concrete has gained significant attention due to the modified interfacial behavior between the coated surface and cementitious materials. This paper proposes an analytical model to describe the bond behavior of enamel-coated rebar spliced in concrete beams. This model considers the strain-softening behavior of concrete in the stress transfer mechanism between spliced rebar and concrete. The local bond strength caused by rebar characteristics and the effect of enamel coating was considered through the unified local bond model. The coupled stress bursting pressure generated by the splice was analyzed using equivalent stress analysis. The proposed model was validated by comparison with the experimental results of 24 concrete beams reinforced with both uncoated and coated rebar. The proposed theoretical analysis and model provide an efficient analytical approach of translating local bond behavior of coated reinforcement to the global bond behavior of lap splices in RC beams. The results indicated a significant coating effect on the load-strain responses of lap splices under tension forces.