Numerical investigation on the structural performance of post-tensioned precast concrete two-way slab-column connections

Nonlinear finite element analyses of post-tensioned modular precast slab-column connections under gravity and lateral loading scenarios were conducted to investigate their structural performance for building construction applications. The simulations were conducted using the commercial finite element software program ABAQUS and assessments were made by estimating connection failure modes, damage development and cracking patterns, mechanisms contributing to connection stiffness degradation, deformability, and load resistance. The influence of prestress loss on the performance of the friction-based connections was investigated under gravity loading and different friction coefficients were employed to examine the sensitivity of the connection performance under reversed cyclic lateral loading to potentially impactful modelling assumptions. Results obtained from the simulations showed that interfacial slip of the post-tensioned friction-based connections did not control connection capacity. The findings also showed that the flexural resistance of modular precast slab elements controlled gravity load resistance, and load resistance of the precast slab-column connections was controlled by the grout crushing at the interface between the precast slabs and columns.