Effect of Different Patterns and Cracking in FRP Wrapping on Compressive Strength of Confined Concrete

摘要

Fiber Reinforced Polymers (FRP) are being introduced into a wide variety of civil engineering applications. These materials have been found to be particularly attractive for applications involving the strengthening and rehabilitation of reinforced concrete structure. The FRP strips provide the necessary longitudinal and hoop reinforcement, as well as a permanent formwork for the concrete core. In return, the concrete core contributes to the overall stability and stiffness of the composite system. A parametric study has been carried out to evaluate effect of number of FRP wrap layers, wrap position and position of crack in wrap on compressive strength of concrete. E Glass fiber wrapping is deployed in the present investigation. Cylinders of 300 mm height and 150 mm diameter were cast with M20 and M40 grade concrete and tested in unconfined and confined conditions with different patterns of FRP wraps such as one layer full wrap, two layers full wrap, 100 mm centre wrap and two strips wrap. Also, edge crack and centre crack were introduced in FRP wrap to understand crack propagation and subsequent loss of strength in the concrete-FRP composite system. Analytical study carried out using ANSYS 10 software shows good agreement with experimental observations. The main objective of this investigation is to optimize FRP wrapping and to predict ultimate compressive strength of FRP wrapped concrete columns.