Shear strength of self-compacting concrete and recycled aggregate concrete beams: an appraisal of design codes

Abstract

Provisions are given in design codes for the calculation of shear strength of conventional concrete (CC) beams. In this paper, a database is generated for self-compacting concrete (SCC) and recycled aggregate concrete (RAC) slender beams with and without shear reinforcement which were investigated for shear strength. Shear capacities of 103 SCC beams and 109 RAC beams with and without shear reinforcement are calculated using the provisions of ACI 318-14, JSCE-2007, NZS 3101-2006 and AS 3600-2009. Calculated nominal shear strengths (Vn) are compared with the experimental shear strengths (Vexp) and statistical parameters are obtained for each code. It was found that all the four codes yielded unconservative estimates of the shear capacities for SCC and RAC beams without shear reinforcement having longitudinal reinforcement less than 1% and depth greater than 450 mm. All the four codes produced reasonable and conservative estimates of the shear capacities of SCC and RAC beams with shear reinforcement. AS 3600-2009 produced minimum average of Vexp/Vn with least scatter but at the same time it yielded maximum unconservative results. A modification in the depth factor of AS 3600-2009 reduced the percentage of unconservative results from 18.67 to 7.8% for SCC beams and 24.67 to 8% for RAC beams without any increase in coefficient of variation (COV).