Research And Application On Polyoropylene Fiber Concrete Kneading Board Mechanics Characteristic

There is a very serious and widespread problem in the concrete structure -crack, it influences the durability of the concrete structure badly. In recent years, polypropylene fiber reinforced concrete is widely used because of its good crack resistance, impermeability and other properties. "Control Panel Concrete Crack" is CFRD important issues, we can mix the polypropylene fiber into the concrete slab, which meets the Dam strength requirements,In lots of existing study about polypropylene fiber concrete cracking, most of them are about the anti-crack-sided and single parameter study, it compared with the lack of systematic analysis of fiber concrete parameter and ratio. Based on the testing study, this paper collects a large number of experimental data and project application information, analyze the impact of the length of fiber, fiber content, fly ash, water-cement ratio to concrete cracking performance; In allusion to the crack resistance affects of the fiber in the concrete, a evaluation approach is proposed and is assessed; In order to study polypropylene fiber concrete performance more comprehensively, in the testing process, the other fiber concrete mechanical properties are also studied. Finally, the associated fiber concrete slab construction example, test the cracking the theory of polypropylene fiber concrete slab. The results are showed:Polypropylene fiber is related to the fiber content and fiber length closely; Fly ash content influence concrete snap strength greatly, when it exceed the best content, the concrete snap strength will decline sharply, and the downward trend line is the linearity; If the fiber content does not change, fiber concrete snap intensity reach the peak in the water-cement ratio 0.30 region, if the ratio exceed 0.30 ,the concrete snap strength begin to decline, if mixing with appropriate admixture, snapping intensity will increase to a certain extent.Polypropylene fiber concrete cracking effect is represented by the crack deformation index formula; The fiber content influence concrete cracking deformation index, if the content is 0.9 kg/m3, cracking deformation index is the smallest, cracking effect achieve the best, increasing to 1.2 kg/m3, cracking deformation index has increased, cracking effect decline; Fiber elastic modulus used is independent of the cracking deformation index; After mixing the fiber, concrete elastic modulus change, with the concrete elastic modulus decline, the cracking deformation index decrease, and the cracking effect is increased .