Statistical analysis of long-term deflections of RC beams

Abstract

This paper statistically investigates accuracy of long-term deflection predictions made by the design code methods Eurocode2, AC318, ACI435, SP52-101 (Russian Code) and the Flexural model proposed by the third author. In the Flexural model extended for the case of long-term loading, modified constitutive relationships for the compressive and cracked tensile concrete have been applied in a numerical technique based on layered approach and the effective modulus method. Deflections were calculated for 238 experimental reinforced concrete members taken from 29 test programs. Influence of variation in such parameters as loading duration, compressive strength of concrete, loading level and reinforcement ratio on prediction results has been investigated by the regression analysis. Accuracy of each technique has been discussed.