Available plastic rotation in continuous high-strength concrete beams

Abstract

An experimental program was formulated to study moment redistribution in continuous high-strength concrete beams. The evaluation of ductility is important for this type of beam as, for high-strength concrete, the ductility decreases as the concrete strength increases. It is therefore necessary to determine whether the critical sections are able to develop appreciable plastic rotations to justify the application of a linear elastic analysis with moment redistribution. This work specifically examined the influence of the tensile reinforcement ratio and the transverse reinforcement ratio on the rotation capacity of plastic hinges. The moment redistribution obtained experimentally is compared with the guidelines recommended in Eurocode 2, CEB-FIP Model Code 1990, and ACI 318. The results show that ACI 318 recommendations for linear analysis with moment redistribution are too conservative and that the predictions, according to Eurocode 2 and CEB-FIP Model Code 1990, agree with experimental evidence.