Researches On Bearing Capacity Of Composite Slab Considering The Effect Of Shrinkage And Slippage Of Cast-in-situ Concrete

Numerical simulation of slab about the whole loading process was done by finite element software ANSYS in this paper. Nonlinear theory of concrete including constitutive model, failure rule (uniaxial and multi-axial relations) and RC nonlinear finite element model (discrete, overall and complex model) are summarized. The application conditions and properties of two main elements Link8 and Solid65 used in simulation are introduced in detail in the paper. The crush disposing of concrete, crack mode and yield rule are discussed systemically. Considering the combination of concrete and rebar, crush of concrete was not considered. A separate model is adopted in the modeling of composite slab.The model of concrete composite slab is established by using the spring element and birth-and-death element based on the ANSYS finite element software. The slippage of laminate surface, secondary loading and shrinkage of cast-in-situ concrete are considered respectively to study ultimate bearing capacity of composite slab and the results are compared with the uniform cast slab. The calculated results indicate that the effect of slippage of laminate surface on the bearing capacity is small. The secondary loading in the construction process can increase the bearing capacity effectively. Meanwhile, the shrinkage of cast-in-situ concrete can weaken the bearing capacity obviously. The bearing capacity is lowered rapidly as the increase of micro- shrinkage strain. The results presented in this paper can provide reference to the engineering application and further research of composite slab.Finally, whole summarization about the study in this paper is presented, and some advices about the direction of future furthering research are proposed.