Shear Behavior of Self-Consolidating Concrete Beams

Abstract

This study investigates the shear behavior of beams made with different types of self-consolidating concrete (SCC). The first type of SCC (SCC1) contained a greater amount of coarse aggregate, than the second type (SCC2). A total of 24 beam specimens were tested: 8 were SCC1 beams, 8 were SCC2 beams and 8 were normal concrete (NC) beams. The parameters included the concrete strength, shear span-depth ratio (a/d), shear reinforcement strength, and spacing of shear reinforcement. Results showed that the overall performance of SCC1 beams is better than or as good as NC beams, but SCC2 beams have inferior structural performance than NC beams in many aspects. Both types of SCC beams have smaller crack widths than NC beams. SCC1 beams had higher diagonal cracking strengths and ultimate strengths than NC beams. The shear ductility of SCC1 beams is comparable with that of NC beams. SCC2 beams had less strength than NC beams. The diagonal cracking and ultimate strengths predicted by ACI 318-08 are conservative for this study. The ACI limit on design yield strength of shear reinforcement may be increased for SCC1 beams based on crack width criterion. These findings indicate that the amount of coarse aggregate can have a significant effect on the shear behavior of SCC in terms of stiffness, strength and ductility. An amount of coarse aggregate greater than 900kg/cu m (56.1 lb/cu ft) is suggested.