Deficient RC Slabs Strengthened with Combined FRP Layer and High-Performance Fiber-Reinforced Cementitious Composite

Nowadays, the strengthening of concrete structures to withstand excessive loads and increase the structure’s ductility, etc., using high-performance fiber-reinforced cementitious composite (HPFRCC) and fiber-reinforced polymer composite (FRP) is very common. In this study, a reinforced concrete (RC) slab under vertical load with different strengthening methods is investigated using the finite element method (FEM). If the concrete strength is 60% lower than the standard design status, the flexural stiffness of the slab is reduced by 75%, and the need for reinforcement is felt. By changing the width of the FRP layer with a strip arrangement from 50 to 100 cm and changing the thickness from 2 to 7 mm per slab with a width of 4 m, the maximum stiffness and bearing capacity are experienced with an increase of 23% and 10%. Also, by changing the width of the FRP layers in the checkered arrangement from 50 to 100 cm and changing the thickness from 2 to 7 mm, the maximum hardness and bearing capacity are experienced with an increase of 22% and 25%. It can be concluded that the use of the checkered arrangement is more effective in increasing the bearing capacity.