STUDY ON SHEAR STRENGTH OF RCA CONCRETE

Abstract

One-way shear behaviour of RCA concrete was investigated by testing longitudinally reinforced simply supported beams having aid of 3.5 under three-point loading arrangement to failure. Two grades of concrete, normal-strength and high-strength were considered and the other variable was the coarse aggregate replacement ratio in the range of 0-1 00%. The decrease in 28 days compressive strength with aggregate replacement ratio was not very signilicant though there was a noticeable drop in the split tensile strength for both the concrete grades. Brittleness of the concrete, when evaluated in terms of the brittleness index increased with increase in the replacement ratio for both the types of concrete. There was a general deterioration of shear behaviour for both concrete types when evaluated in terms of normalized shear strength and shear ductility as the replacement ratio increased from 0 to 100%. Conservative predictions of the measured shear strengths were observed from selected current design codes and predictive models available in the literature. The most accurate though conservative predictions were obtained from the RESPONSE-2000 a computer programme based on MCFT and overly conservative predictions were obtained from IS 4 56:2000