Analysis of shear-critical reinforced concrete beams

Recent experience among some researchers suggests that analysis methods bas ed on the smeared rotating crack concept do not adequately model the respon se of shear-critical concrete beams containing little or no shear reinforce ment. Application of the modified compression field theory (MCFT), one of t he first such rotating crack models, to the analysis of shear beams is addr essed herein. The original constitutive relations are re-examined, and a cr ack width limit and residual tension term are introduced. When incorporated into a non-linear finite element procedure, the model is shown to adequate ly simulate the strength, stiffness, ductility, and failure mode of lightly reinforced shear-critical test beams. Sectional analysis procedures based on the same model are also shown to provide accurate predictions of respons e. Prevailing mechanisms are discussed, and aspects of the model in need of further refinement are also identified.