Lower bound analysis for shear assessment of full-scale RC girders subjected to axial tension

Abstract

Axial tension force exerted as a result of a temperature change or shrinkage can cause the collapse of RC structural members. Design code provisions and analytical models such as Modified Compression Field Theory (MCFT) yield reasonable estimates of shear strength of RC beams subjected to axial tension. Nevertheless, their semi-empirical nature is not necessarily appropriate for shear assessment of existing RC structural members. The extra conservativeness and empirically determined parameters might require unnecessary maintenance work. A generalised model with rigorous formulation must be developed. This paper presents a purely theoretical model to predict the shear strength of RC beams under axial tension based on limit analysis. Without regressive functions and empirical functions, lower bound analysis enables shear strength derivation when the force equilibrium and strain compatibility are satisfied. Accuracy of the analysis was verified by comparison of its predictions with three experimental shear strengths of full-scale RC girders. An equal level of accuracy was observed betweenthe analytical solutions and MCFT-based predictions.