MONOTONIC TEST AND CALCULATION METHOD OF CONCRETE FRAME WITH PRECAST BEAMS AND CAST-IN-PLACE COLUMNS

A six-story two-bay concrete plane frame with precast beams and cast-in-place columns was tested under monotonic loading, and the behavior of the specimen was evaluated based on failure modes, failure mechanism, displacement ductility, etc. The results indicated that the specimen attained the anticipated failure mechanism, i.e. a mixed mechanism. Plastic hinges firstly appeared in the beam-end, and the plastic hinge did not appear at the column-end until a number of plastic hinges formed at the second and third floor beam-ends during the test. The stirrups in the joint were elastic from beginning to end. The global displacement ductility factor of the specimen was 6.3, which suggested that it was a feasible method to design concrete frames with precast concrete beams and cast-in-place concrete columns in conformity with the current standard anti-seismic design of cast-in-place reinforced concrete structures. The internal force calculation method considering the reduced rigidity of precast beams and the internal force calculation method considering the reduced connection stiffness were investigated by MIDAS, and primary suggestions for calculating internal force of precast concrete frames were presented.