Experimental Study On Mechanical Properties And Durability Of Synthetic Fibre Reinforced Concrete

In recent years, synthetic fibers are used in concrete to improve ductility and the mechanical properties of concrete, making the synthetic fiber reinforced concrete been extensively in engineering applications. And polypropylene fibers, polyvinyl alcohol fiber, are cheaper than steel fiber, showing good properties in anti-acid aspect and so on. This paper studies about the polypropylene fiber reinforced concrete and polyvinyl alcohol fiber reinforced concrete and carried out the basic mechanical properties and durability tests based on four influencing factors of sand ratio, fiber morphology, fiber length and fiber content, to analyze the compressive strength, splitting tensile strength, flexural tensile strength, flexural toughness and resistance to chloride ion penetration ability. The analysis includes:(1) When the sand ratio was50%,60%and70%respectively, the slump values, mechanical properties and resistance to chloride ion penetration study results of PP fiber reinforced concrete show that when the sand rate increases, the slump reduces and monofilament fibers of the compressive strength, splitting tensile strength decrease and the bending strength of the ability and chloride ion penetration resistance improve.(2) The slump, mechanical properties and resistance to chloride ion penetration of four different types of fibers concrete are compared. The test found that the PP monofilament fibers and PVA fibers significantly impact the concrete mobility. Except for the PVA fiber reinforced concrete, the other fiber reinforced concrete’s compressive strength, flexural tensile strength decreased, while the splitting tensile of concrete was improved. The resistance to chloride ion penetration ability of steel-like PP fiber reinforced concrete was the best.(3) The monofilament fibers of different lengths and PP steel-like fiber were compared. The results show that the increasement of the aspect ratio make the slump of concrete larger, while compressive strength, splitting tensile strength were also improved. Steel-like Ppfibre and monofilament fiber reinforced concrete resistance to chloride ion penetration ability performanced differently to each other with the increase of aspect ratio.(4) The changing PVA fiber content of0,0.5%,1.0%,2.0%were compared. The results show that the slump of fresh concrete declined with increasing fiber content, while compressive strength, splitting tensile strength, flexural tensile strength slightly increased. And resistance to chloride ion penetration ability gradually increased. But if the fibre content is greater than 1%, the mechanical properties and resistance to chloride ion penetration ability decreased significantly.