Ofonime A. Harry^1,, Ifiok E. Ekop²

Shear provisions in codes are based on empirical equations derived from experimental test results without any rational theory to explain its behavior. Some of these expressions, for example BS 8110, ACI 318 and Eurocode 2 takes into account the effect of reinforcement ratio, effective depth and concrete compressive strength while Canadian code considers the shear strength to be a function of concrete compressive strength only. The new Model code 2010 considers the shear strength of beams as a function of longitudinal strain in the web. This brings about disparity in shear strength prediction from different codes. This paper examines the accuracy of shear strength predictions in beams without shear reinforcement. The study involves a comparative analysis of shear strength predictions from five different codes: BS 8110, Eurocode 2, Canadian code, ACI code 318 and Model code 2010. A total of 435 experimental test results from database of shear critical beams in literature were used for the study. The results shows that Model code 2010 shear strength prediction is the most conservative among the five codes shear provisions considered in this study. This may be due to the assumed linear elastic state of the flexural reinforcement at the point of failure in shear. BS 8110 and Eurocode 2 predictions gave the least variation compared to other codes predictions. The highest number of unsafe shear strength predictions was obtained from Canadian code followed by prediction s from ACI 318.

shear strength, concrete compressive strength, database, effective depth, reinforcement ratio, shear reinforcement, longitudinal strain