Analytical study of a cast-in-place joint of a precast prestressed concrete frame under cyclic load

Abstract

The researchers focused mainly on the types of connections in precast frame structures and the seismic behaviour of the different types of those

connections. There are two types of connections in moment-resisting precast frames the first type is equivalent monolithic systems, which composed of precast concrete columns and beams connected by cast-in-place connections, the second type is jointed systems in which the connections are weaker than the adjacent concrete elements. The research presents an analytical study of the behaviour of one type of equivalent monolithic system consisting of a cast-in-place middle joint of a prestressed precast concrete frame under cyclic loading by using ABAQUS.19. The cast-in-place joint is provided with U-shaped steel reinforcing bars that overlap the pre-anchored cables and longitudinal reinforcement in the beam to ensure continuous transfer of loads. To improve the behaviour of the cast-in-place joint, several parameters were changed (the compressive strength of the cast-in-place concrete, the diameter of the U-shaped reinforcing bars and the dimensions of the shear key) The most important conclusions reached in this research are that by increasing the compressive Strength of cast-in-place concrete in the joint area, the joint strength increased and the plastic dissipated energy increased. As the diameter of the U-shaped reinforcing bars increased, the strength of the joint increased and the plastic dissipated energy in the joint decreased. The strength of the joint also increased, and the plastic dissipated energy increased as the dimensions of the shear key increased.