Evaluation of Synthetic Fiber Reinforced Concrete Pipe Performance Using Three-Edge Bearing Test

Synthetic fibers have recently been used in a concrete mix in an attempt to produce a new concrete pipe system that is cheaper, lighter, and more flexible than conventional steel reinforced concrete pipes. However, no structural design codes have been introduced for synthetic fiber reinforced concrete pipes evaluation. There is little in the literature regarding synthetic fiber applications in concrete pipes. This study focuses on the evaluation of the synthetic fiber reinforced concrete pipes in terms of ASTM requirements for strength, stiffness, and ductility. The performance of the synthetic fiber reinforced concrete pipes was evaluated using a three-edge bearing test in accordance with ASTM protocols and using three pipe diameters: 600, 1,200, and 1,500 mm. Fiber dosages ranged from 4.75 to 18 kg/m3, and different areas of one steel cage layer were used to reinforce the concrete pipes. The results show that using synthetic fiber increased the cracking load (produces 0.3-mm crack width), ultimate load, stiffness, and ductility of tested pipes. Also, using synthetic fiber lowered the production cost, as the reduction in the steel cage area ranged from 51 to 100 %.