FRP-Confined Concrete Composite Retrofit System for Structural Steel Columns

Abstract

AbstractFiber-reinforced polymer (FRP)–confined concrete-steel composite columns have been recently introduced as a retrofit technique for structural steel columns. This technique involves placing a two-part FRP tube around an existing steel column and subsequently filling the void between the steel section and the FRP tube with concrete to create a composite column. The composite action occurs due to the concrete encasing the steel section and the FRP confining the concrete. Within this focus, an experimental investigation has been undertaken with the objectives of evaluating the effect of adding confined concrete to encase a steel W section, the effect of using a split-tube system as a practical encasement technique, and the effect of adding shrinkage-reducing admixtures (SRA) to the confined concrete. A total of 18 stub columns comprising six different column types were tested to achieve these objectives. The test results showed that the load-displacement response of the composite columns was similar t...