Strengthening of Plain Concrete Cylinders with Natural FRP Composite Systems

摘要

This paper reports the performance of plain concrete cylinders confined externally with fiber-reinforced polymer (FRP) composites with natural sisal as the reinforcement. Strength tests are performed on plain concrete cylinders confined with different sisal FRP thicknesses such as 1, 2 and 3 layers. The results show that external confinement with sisal FRP enhanced the axial load-carrying capacity, ductility and energy absorption of concrete compared to control specimens. For predicting the ultimate strength of sisal FRP-confined concrete a new strength equation was developed based on the lateral confining pressure of sisal FRP which shows a good agreement with the experimental results. To assess the durability criteria, sisal FRP-filled concrete specimens are exposed to severe environmental factors such as variation in temperature, alternate wet and dry cycling and exposure to alkaline condition. The outcomes indicate that sisal FRP-confined specimen subjected to temperature variation has shown a remarkable increase in strength, whereas alkaline exposure has exhibited a decrease in strength.