Shear strength of slender reinforced concrete beams without web reinforcement: A model using fuzzy set theory

A reliable shear strength model for slender reinforced concrete beams without web reinforcement is described based on fuzzy set theory. The fuzzy-based model was developed to consider the interaction between the shear modeling parameters and the random and non-random uncertainties in these parameters. The parameters were identified essential for modeling shear strength in slender reinforced concrete beams without web reinforcement being: the compressive strength, the effective depth and the tension reinforcement ratio. A total of 385 experimental datasets obtained from shear tests of simply supported reinforced concrete beams from the literature, are used in learning/developing and verification of the proposed model (164 for learning and 221 for verification). The shear strength predicted by the fuzzy-based model was compared to those predicted by current shear strength models suggested by design codes such as the Eurocode 2 (EC2), the American code ACI (318-05), and Canadian code (CSA A23.3-04). The fuzzy-based model yields a significant enhancement in the prediction of the shear strength while still respecting principles of mechanics governing shear failure in concrete beams. (C) 2009 Published by Elsevier Ltd