Shear capacity of reinforced concrete transfer beams reinforced with longitudinal steel

摘要

Results of the detailed experimental investigation on the behavior and ultimate shear strength of reinforced concrete Transfer (deep) beams in high-rise buildings are summarized. The cube compressive strength of concrete f_(cu) is 43 MPa and the shear span-to-effective depth ratio (a/d) is 1.10. The main variable of the experimental program is longitudinal steels, ranges from 0.28 to 1.20%. Observations are made on failure modes and ultimate shear strength. Test results showed that the percentage of longitudinal steel and its placement across the depth of the beam specimens is a significant parameter in enhancing the ultimate shear strength and the failure mode. The results from the experi-ments have been processed suitably to come out with empirical expressions for estimating the shear capacity of beams incorporating variables such as compressive strength of concrete, percentage of longitudinal and vertical steels, depth of beam in terms of shear span-to-depth ratio. Further, the comparisons of shear design provisions of four National codes viz.: (i) ACI318-2002 (ii) CIRIA Guide-2, (iii) BS 8110-1997, (iv) IS 456-2000 for the prediction of shear strength of Transfer beams shear span-to-depth ratio < 2.00, have been made with a view to seeing their goodness of fit against the experimental values.