Experiments for Strength Properties of Polypropylene Fiber-reinforced Concrete

This paper made experimental research on the compressive strength, axis compressive strength and splitting tension strength of polypropylene fiber-reinforced concretes at a fiber content of 0.9Kg/m(3) in different ages which showed that: in the experiment of compressive strength, the strengths of C20 polypropylene fiber concretes in the ages was lower; the strength of C30 polypropylene fiber concretes in the age of 7 days was lower, the strengths in the ages of 14 days and 28 days were basically equal to; the strength of C40 polypropylene fiber concretes in the age of 7 days was basically equal to and in 28 days was higher than the strengths of ordinary concretes. In the experiment of axis compressive strength, the strengths of C20 polypropylene fiber concretes in the ages were lower; the strengths of C30 polypropylene fiber concretes in the age of 7 days and 14 days were lower and in the age of 28 days was basically equal to; the strengths of C40 polypropylene fiber concretes in the ages were basically equal to the strengths of ordinary concretes. In the experiment of splitting tension strength, the strengths of C20 and C30 polypropylene fiber concretes were lower; the strength of C40 polypropylene fiber concretes in the age of 28 days was basically equal to the strengths of ordinary concretes. Conclusion: the relationships between the strength of fiber concretes and ordinary concretes are correlated to the strength grades of concretes, namely, When the strength degrade of concretes is low, the strength of polypropylene fiber concretes is lower, but the strength reaches closer to or exceeds the strength of ordinary concretes along with the increase of the strength grade of concretes.