Ductility and linear analysis with moment redistribution in reinforced high-strength concrete beams

摘要

The evaluation of the ductility of reinforced concrete beams is very important, since it is essential to avoid a fragile collapse of the structure by ensuring adequate deformation at the ultimate limit state. One of the procedures used to quantify ductility is based on deformations, namely, the plastic rotation capacity. Knowledge of the plastic rotation capacity of certain regions of the structure is important for a plastic analysis or a linear analysis with moment redistribution. An experimental program is described in this article. It is composed of 10 tests designed to study the moment redistribution and ductility of continuous high-strength concrete beams. Particular care was given to analysing how the tensile reinforcement ratio and the transverse reinforcement ratio influence the plastic rotation capacity of the beams. A comparative study was carried out on several codes related to the moment redistribution permitted and the experimental findings. It was found that some of the recommendations are unsafe. It was also found that high-strength concrete beams, when properly designed, have enough deformation capacity to be used in plastic analysis.