Flexural behavior of reinforced concrete slabs strengthened with CFRP plates and CFRP anchors

• A total of nine slab specimens, consisting of one control slab and six strengthened slabs, were tested and presented in this report. • The slabs were strengthened with CFRP plates and CFRP anchors to increase flexural capacity. • Debonding failure by delamination of CFRP plates was observed for all strengthened slabs, and different failure modes were observed due to different applications of CFRP anchors. • The analytical flexural capacity of the slabs was calculated using a fiber element model, and a computer program was developed. • The debonding moment equation was modified by proposing new constants, and then the equation was applied to the developed computer program. • The strain distribution obtained from the analytical study proves that strengthened reinforced concrete slabs show smaller tensile strain values due to the presence of the CFRP plate. This paper presents an experimental study on the flexural behavior of reinforced concrete slabs strengthened with CFRP plates and CFRP anchors. The aim of this study, apart from observing the effect of CFRP anchor application on the flexural behavior of the slabs, is also to obtain a debonding moment equation by modifying the existing equation. Nine specimens were tested to failure with the test variables of anchor distance and anchor installation location in the shear span and pure moment zones. The load-displacement response and the failure mode of each specimen are discussed in this paper. The test results show that the flexural capacity of reinforced concrete slabs with CFRP plates increases by 146 % compared to specimens without CFRP plates. Although debonding failure occurs, CFRP anchors can reduce the extent of debonding between the CFRP plate and the concrete substrate. The equation for calculating the debonding moment value of reinforced concrete slabs strengthened with CFRP plates was modified by replacing the coefficient in the existing equation with the new coefficient 9.45 obtained from a simple statistical analysis.