عنوان مقاله [English]
This paper presents the results of axial pressure testing on reinforced concrete columns (RCC) loaded with confined normal concrete (NC) and high-strength concrete (HSC) using glass-fiber reinforced plastic pipes (GRP) casing as well as carbon fiber reinforced polymer (CFRP). This study aimed to evaluate the behavior and mechanical properties of columns confined with GRP and FRP under pressure loads. The major parameters in the experiments were the types of concrete, the effect of GRP and FRP wrapping, as well as the number of FRP layers. 12 cylindrical RCC (150*600 mm) were prepared and divided into two groups, NC and HSC, and each group was divided into two parts. In each part, one column was without FRP, a column was wrapped with one layer and another column with two layers. All columns were tested under concentrated compression load. The results showed that the utilization of FRP and GRP improved compression capacity and ductility of RCC. The addition of one and two layer-FRP wrapping increased compression capacity in the NC group to an average of 18.5% and 26.5% and in the HSC group to averagely 10.2% and 24.8%. Meanwhile, the utilization of GRP increased the compression capacity of the columns by 4 times in the NC group and 3.38 times in the HSC group. These results indicated that although both FRP and GRP result in confinement, the GRP resulted in increased compression capacity and ductility of the RCC due to higher confinement. Furthermore, the confinement effect was higher on the first group.