The Performances Experiment Study Of Concrete With Polypropylene Fiber And Glass Fiber

Recently, the cracks of concrete are common in building structures, they appear in the slab of roof, the slab of wall, basement and so on. They affect the safety and durability, and lead to trouble and compensation in real estate. Although many of clacks do not affect the safety of building, people believe that the cracks are the sign of dangerous, and are afraid of the cracks. Control and eliminate the crack as far as possible become the problem for many experts and scholars. Mixing fiber into concrete can control cracks effectively, and improve the behavior of cracks-resisting. Recently, the study and use have made grate progress.In this paper, two theories to explain the mechanic principles of concrete mixed with fiber are introduced. The two theories are the theory of complex material and the theory of fiber space. The calculate formulas of strength of extension about complex material are deduced. Through experiment this paper study the affect of concrete performances mixing with liter polypropylene fiber and glass fiber. The performances are compression strength and extension strength. The change of extension strength is analyzed with the theory of complex material. At the same time, this paper collects a lot of experiment data which were done by experts and scholars of our country and foreign country. On the base of different mixing ratio, compare the affect of concrete performances mixing with liter polypropylene fiber and glass fiber. Through experiment this paper compares the crack load of concrete slab with liter polypropylene fiber and glass fiber, and compare with the numerical value of theory. In the calculation assume stress figure of the extension area is triangle or rectangle. This paper analyses the cause of common crack in the engineering, summarizes the cracks-resisting experiment which were done by many experts with fiber, and adopts the theory of fiber space to approach mechanization of cracks-resisting.From the experiments, we can see the affect of concrete performances mixing with liter polypropylene fiber and glass fiber is minor. Compare with common concrete, the crack-load of concrete slab mixing with liter polypropylene fiber and glass fiber is marked improved. Mixing with liter polypropylene fiber and glass fiber, the behavior of cracks-resisting of is marked improved, and the cracks are controlled and smeller.