Poststrengthening of Concrete Slabs: Full-Scale Testing and Design Recommendations

Abstract

This paper reports on an experimental research project concerning the poststrengthening of concrete slabs with externally bonded carbon fiber reinforced polymers (CFRP). The two problems studied were strengthening in order to double the load-bearing capacity of slabs and restoration of the original load-bearing capacity of rebars that had been accidentally cut. To this end, the load conditions and the geometrical conditions of steel rebars as well as the length and distribution of CFRP strips were varied. Design, test setup, and selected results of the tests are presented and discussed. On the basis of these tests, design recommendations are given for strengthening and repair. These design recommendations are consistent with the steps typically used for the design and dimensioning of slabs and beams in structural concrete. These steps include calculation of the bending resistance, the shear resistance and the anchoring length of the reinforcement.