Comparison of mechanical properties of concrete and design thickness of pavement with different types of fiber-reinforcements (steel, glass, and polypropylene)

In this study, the effect of different fiber-reinforcements was investigated on the mechanical properties of normal strength and high strength concrete. Then using the mechanical properties of concrete, the design thickness of jointed plain concrete pavement was evaluated under the same traffic-loading conditions. For this purpose, three different fiber-reinforced concretes were produced using a 1% volume fraction of hooked steel fiber, polypropylene fiber, and glass fiber, respectively. Studied mechanical properties include compressive strength, flexural strength, and residual strength. The results of mechanical testing show that steel fiber is superior in enhancing the compressive and flexural strength compared to glass and polypropylene fiber. The net gain in flexural strength and residual strength due to steel fiber is almost twice compared to that caused by polypropylene and glass fiber. 1%steel fiber incorporation reduced the design thickness of pavement from 183 to 120 mm for normal strength concrete and 155 to 105 mm for high strength concrete. Owing to the best flexural performance, steel fibers were the most effective in reducing the design thickness in comparison with polypropylene and glass fibers. But cost to benefit ratio analysis suggests that steel fiber-reinforced concretes are not economical compared to glass fiber and polypropylene fiber-reinforced concretes for the same load-carrying capacity. Therefore, for the same performance, glass and polypropylene fiber-reinforced concretes can provide cheaper pavements than steel fiber-reinforced concrete and conventional plain concrete.