Numerical Investigation of Fiber Reinforced Polymer Retrofitted Short Reinforced Concrete Circular Columns under Concentric Compressive Load

Abstract

The presents study numerically investigates the fiber-reinforced polymer (FRP) retrofitted shortdamaged reinforced concrete (RC) columns subjected to axial compression load. The main parameter considered to evaluate the effectiveness of FRP retrofitting on circular columns with different aspect ratios, concrete grade, and FRP material. To simulate the behaviour of a short RC column under a uniaxial compression load, a finite element model of the column was developed. The model was then modified to simulate the various level of damage to the column and the behaviour of the column under uniaxial load. The effectiveness of FRP retrofit was studied comparing the behaviour of the retrofitted column to the damaged column. For M20 concrete column retrofitted with carbon fiber reinforced polymer (CFRP) showed a higher strength (2 to 3 times) than glass fiber reinforced polymer (GFRP) retrofitted columns. For M30 concrete, the range is quite similar (1.5 -2.3 times more). The effectiveness of both FRPs retrofitted columns increases with increasing aspect ratio from 2 and 3, but slightly decreases for an aspect ratio of 4 compared to the damaged specimen. The maximum effectiveness achieved for CFRP retrofitted columns is of 19.45% and for GFRP retrofitted column is of 10.71%, and the other grade of concrete (M30) followed a similar trend. The load-bearing capacity of columns has no significant effect by the increase in aspect ratio from 2 to 4.