Evaluation and comparison of GFRP casing and CFRP sheets application on the behavior of circular reinforced concrete column made of high-strength concrete

Abstract

This paper presents the results of axial compression testing on reinforced concrete columns (RCC) made with high-strength concrete (HSC) and confined by glass fiber-reinforced plastic (GFRP) casing and carbon fiber-reinforced polymer (CFRP). The major parameters evaluated in the experiments were the effects of GFRP casing, CFRP wrapping, and the number of CFRP layers. In this study, six cylindrical HSC-reinforced concrete columns (150 mm diameter and 600 mm height) were prepared and divided into two groups; with and without GFRP casing. In each group, one column was without CFRP, a column was wrapped with one CFRP layer, and another column with two CFRP layers. Concrete compressive strength was 63.1 MPa. All columns were tested under concentrated compression load. Results indicated that the utilization of CFRP wrapping and GFRP casing improved compression capacity and ductility of reinforced concrete columns. The addition of one and two CFRP layer wrapping increased compression capacity to an average of 10.2% and 24.8%, respectively; while the utilization of GFRP casing increased the compression capacity of the HSC columns by 3.38 times. These results indicate that although both CFRP wrapping and GFRP casing resulted in confinement, the GFRP casing has a higher effect on increased compression capacity.