Time-Dependent Analysis of Reinforced Concrete Two-Way Slabs Strengthened with External FRP and Steel Plates

This study aims to predict the long-term behavior of fiber-reinforced plastic (FRP) or steel plates externally strengthening RC two-way slabs using ANSYS software non-linear finite element (FE) modeling and making a comparison between the FE analysis with the experimental test results, in addition, calculated the effect of parameters on the strengthened slab behavior: compressive strength, the magnitude of sustained load, slab length to slab thickness, and the external strengthening type. The Prony series were used in the model of non-linear viscoelastic in this paper to study the deflection of time-dependent adopted. The modeling was done to solve the problems of the creep by the FEs by ANSYS software, the results showed an acceptable agreement level with the results of the experiment. The parametric study's numerical results indicate that as sustained load increases for 20-60% Pu kN, the time-dependent deflection increases by around 2.5 times, as well as a decrease in the long-term efficiency of the slabs that external strengthening where the deflection is increased due to increased creep, and the effect creep has on the deflection.