PERFORMANCE OF CONCRETE SLAB REINFORCED BY CFRP BARS AND STRENGTHENED BY DIFFERENT LAYOUT OF CFRP LAMINATES

Abstract

In recent years, Fiber Reinforced Polymer (FRP) rebar has been adopted to reinforce structural concrete elements such as slabs. FRP strips are also increasingly used to reinforce or strengthen concrete members that require higher carrying capacity or to restore damaged structural elements. Therefore, the reinforcement of concrete structures with this material is increasing but the effect of variables on CFRP-reinforced concrete slabs and externally bonded with CFRP laminates has not been evaluated in detail. This study presents a numerical analysis of the structural performance of concrete slabs reinforced by CFRP bars and strengthened by CFRP laminates using a finite element approach with ANSYS software. Six models with the same geometry (1550x1550x100 mm) were analyzed. Four models were reinforced with CFRP bars and externally strengthened with CFRP laminates, one model was reinforced with CFRP bars without external strength, and one reference model with traditional reinforcing bars (control specimen). Different parameters were adopted, such as amounts of FRP bars and CFRP laminates layout in which some models contained both CFRP bars and CFRP laminates. A uniformly distributed load that was calculated by plastic analysis was applied at the top surface area of each model. The plastic load considers the contribution of the laminated CFRP strips that increased the strength of the slab. Analysis results in the maximum strength carrying capacity in equivalent CFRP bars exhibit higher strength percentages of 5.07% of load capacity but differed in mode of failure than conventional reinforcements control slab.