Experimental study of the reinforcement effect of macro-type high strength polypropylene on the flexural capacity of concrete

- Flexural capacity of concrete reinforced with high strength PP fibers was evaluated.
- Stress-deflection curves, residual strength, and energy absorption were discussed.
- Residual strength was defined using average stresses for a period of deflection.
- Effect of high strength PP fiber content on the flexural performance was evaluated.
- Effect of high strength PP fiber on normal and high strength concrete was evaluated.

In this paper, an experimental study was performed to examine the flexural capacity of concrete reinforced with macro-type high strength polypropylene fiber. Four fiber volume fractions, 0.25, 0.5, 0.75, and 1.0%, and three concrete compressive strengths, 30, 40, and 60 MPa, were involved to determine the effects of the high strength polypropylene fiber on the flexural capacity of fiber-reinforced concrete. The stress and deflection curves, residual strength, and energy absorption capacity obtained from the experiment were used to investigate the flexural capacity of high strength polypropylene fiber-reinforced concrete, particularly in high strength concrete. High strength concrete reinforced with a 0.25% volume fraction of high strength polypropylene fiber showed a flexural capacity lower than normal strength concrete reinforced with the same volume fraction. The reinforcing effect of the high strength polypropylene fiber in the flexural capacity of high strength concrete was excellent at volume fractions more than 0.50%.