Seismic performance of reinforced concrete frames with precast prestressed flooring system
In a current research project the influence that floor slabs containing precast prestressed units have on the seismic performance of plastic hinges in beams of moment resisting frames is being examined. A three dimensional, approximately half scale, one storey, two bay moment resisting frame together with adjacent floor slab has been constructed and tested. The experimental results show that the building code, ACI 318-05, underestimates the flexural strength of beams by a considerable margin. An analytical model has been developed which predicts the flexural, shear and elongation response of plastic hinges in beams subjected to inelastic rotation history and varying axial load levels. This model can be used to predict the interaction between beams in moment resisting frames and floor slabs containing precast prestressed units. Analysis using this model shows good agreement with the experimental results.