A study of strength and impact resistance of functionally graded concrete using polypropylene fiber and fly ash

Abstract

This paper focuses on an evaluation of compressive strength, flexural strength, and impact resistance of functionally graded concrete (FGC) with two concrete layers (including top and bottom layers with a same height). Various types of concrete were normal concrete, fly ash concrete with a replacement of cement by fly ash at 20 % by mass, and fiber-reinforced concrete with an amount of polypropylene (PP) fiber at 0.3 % by volume. The results showed that using fly ash in combination with PP fibers significantly improved the compressive strength, flexural strength, and impact resistance of FGC at 28 days. As a consequence, FGC made from a top layer of fly ash concrete and a bottom layer of fly ash concrete containing PP fibers was the most optimal one which ensures bearing capacity and meets economic aspect in this paper.