Chiang Mai Journal of Science

     This paper demonstrates the effect of bond-interfaces slip on the shear responses within the non-ductile reinforced concrete (RC) columns. Those columns were conducted as the flexure-shear critical members, which were commonly found in the existing RC frame structures constructed before the regulation of recent seismic codes. To represent the behaviors of those columns, the proposed model is developed within the framework of the forced-based formulation under the Timoshenko beam kinematic assumption. The axial-flexure interaction of the RC frame element is considered through the fiber-section model while the shear action couples to the flexural action through the UCSD shear-strength model within the shear constitutive model. Finally, one simulation is employed to verify the model performance to predict complex behaviors of the non-ductile RC columns for seismic analysis and to discuss the effect of bond-interfaces slip on those responses. From the results, it confirms that the proposed model is simple but accurate. Furthermore, the model can well represent several salient features of the non-ductile RC columns such as the shear-flexure interaction effect, the strength degradation in shear due to the increasing curvature ductility demand, the gradual spread inelasticity, and the weakened shear responses due to the bond-slip effect. The predicted maximum shear force is well corresponding to the value obtained from the experiment with an error of about 0.83% while the error obtained from the frame model without the bond-slip effect is about 2.58%.