关键词: 纤维增强混凝土, 合成聚丙烯纤维, 聚丙烯腈纤维, 冲击试验, 冲击韧性

Abstract: Thenormal concrete is easy to crack and its toughness is poor. In this paper, different lengths of synthetic polypropylene fiber and polyacrylonitrile fiber are mixed into normal concrete to improve the brittleness and toughness of concrete. Through the concrete impact test device, the drop weight impact test was carried out on the cube specimens of synthetic polypropylene fiber concrete, polyacrylonitrile fiber concrete and ordinary concrete. In the experiment, 20 mm synthetic polypropylene fiber, 40 mm synthetic polypropylene fiber and monofilament polyacrylonitrile fiber were added into the concrete, respectively. The influence of synthetic fiber on the impact load of concrete was studied by changing the fiber content. The content of each fiber was 1 kg/m³, 3kg/m^3,  6kg/m³, 9kg/m³. The experimental results show that the impact resistance of fiber reinforced concrete increases significantly with the increase of fiber content. The impact toughness of fiber reinforced concrete with 40mm length and 9 kg/m³ synthetic polypropylene fiber is the best, which is 306.67% higher than that of normal concrete.

Key words: fiber reinforced concrete, synthetic polypropylene fiber, polyacrylonitrile fiber, concrete impact test, impact toughnes