Investigation of precast RC beam-column assemblies under column-loss scenario

•Progressive collapse of precast RC beam-column joints was numerically investigated.•Three specimens tested under middle column-loss scenario were used for validation.•Tests included two precast specimens and one monolithic specimen.•Revised precast RC beam-column joint details were numerically investigated.•New joint efficiency parameters are proposed for progressive collapse assessment.

The progressive collapse of reinforced concrete (RC) buildings, being one of the most critical failure scenarios, is a great concern for the structural engineering community. As precast concrete buildings are deficient in structural continuity, these are more vulnerable to progressive collapse than cast-in-situ RC buildings. The goal of this study is to develop a nonlinear finite element (FE) model using LS-DYNA software to predict the performance of precast non-prestressed RC beam-column assemblies, each comprising three columns and two beams, under column-removal scenario. The model takes into account the nonlinear behavior of concrete and steel, strain rate effect on material properties and contact between surfaces at the joints. The FE models were calibrated against three half-scale specimens tested under middle column-removal scenario. Tests included two precast specimens and one monolithic specimen with continuous top and bottom beam reinforcement. The validated FE modeling was further extended to study the progressive collapse potential of seven revised precast connections. As a result of the FE study, new joint efficiency parameters were introduced in this research.