Effective Technique to Prevent Failure of CFRP Confined Columns

The confinement of concrete columns has been the subject of several experimental investigations utilizing a variety of methodologies. An elliptical concrete column confined with externally bonded carbon is an effective technique to improve the behaviour of reinforced columns and is considered a superior choice for rehabilitation. The experimental program of the current study includes 20 tests conducted on elliptical concrete columns confined with externally bonded carbon fibre-reinforced polymer (EB-CFRP) laminates. The purpose of the study is to assess how confinement efficacy is affected by the elliptical aspect ratio (A/B) and confinement number of EB-FRP layers. The tests involved a series of unstrengthened control concrete columns, and three further strengthened series, corresponding to one, two, or three layers of EB-CFRP sheets, respectively. For each series, five elliptical aspect ratios (A/B) with values between 1.0 and 1.6 were considered. In order to quantify the confinement level with the number of EB-CFRP layers as a function of elliptical aspect ratio, the results of compressive concentric tests were studied till failure. The findings demonstrate significant improvements in the EB-CFRP confined columns' ductility and compressive strength. In addition, this enhancement improves with the number of EB-CFRP layers, suggesting a proportionate link between CFRP layer’ number and compressive strength. However, the confined columns' ductility and compressive strength decreased as the elliptical aspect ratio increased.