Effect of Variables on Shear Strength of Concrete Beams

Although considerable research has been conducted on the shear strength of reinforced concrete members without web reinforcement, the debate as to the effects of the major variables on the ultimate shear strength (vu) and cracking shear strengths (vc) has yet to be unequivocally established. Previous research on the subject has at times been unclear or often yielded contradictory results. The intent of this paper is to shed some light and clarify some of the misconceptions regarding the effects of the compressive strength (fc), tensile reinforcement ratio (), and shear span-to-depth ratio (a/d) on vu and vc of steel-reinforced concrete beams without web reinforcement. The analysis uses extensive shear strength data retrieved from existing literature for both normal strength and high strength concrete members. Results show that a/d significantly affects vu, whereas its effect on vc is much less significant. The effect of fc on vc is not negligible and should be accounted for in strength analysis. The impact of on vc is insignificant in the case of short beams (a/d < 2.5).