FRP-confined Concrete Cylinders: Axial Compression Experiments and Strength Model

The present article deals with the analysis of experimental results, in terms of load-carrying capacity and strain, obtained from tests on plain-and reinforced-concrete (RC) cylinders strengthened with external carbon-fiber-reinforced polymer (CFRP). The parameters considered are the number of composite layers and the compressive strength of unconfined concrete. The effective circumferential FRP failure strain and the effect of the effective lateral confining pressure were investigated. In total, 30 cylinders were subjected to axial compression, which included control specimens. All the test specimens were loaded to failure in axial compression and the behavior of the specimens in the axial and transverse directions was investigated. Test results showed that the CFRP wrap increases the strength and ductility of plain-and RC cylinders significantly. A simple model is presented to predict the compressive strength and axial strain of FRP-confined columns.