Compressive Behaviour of Concrete Cylinders Reinforced with Glass Fiber Reinforced Polymer Bars

Abstract

Current design standards ignore any contribution of glass fiber reinforced polymer (GFRP) bars in concrete in a state of compression. This paper challenged this convention by testing 30 cylinders of 36 MPa concrete to failure in pure axial compression. The testing matrix consisted of control groups of plain and steel-reinforced concrete specimens which were used to benchmark groups of concrete specimens reinforced with commercial and modified GFRP bars. Cylinders were built in 4, 6, and 8 bar arrangements with nominal diameters of 10M or 13M and with concrete cover 25 mm, cylinder diameter 150 mm and height 300 mm. The GFRP bars were found to exhibit crushing failure long after the concrete in the cylinders had been crushed. Commercial GFRP bars significantly increase the toughness of the specimens over unreinforced concrete, outperforming both steel and modified GFRP reinforcement in this metric. However, steel reinforcement proved to increase peak load the most over unreinforced concrete, with commercial and modified GFRP reinforcement increasing peak load by less than half as much as steel.