The Study On The Anti-Cracking And Waterproof Of The Polypropylene Fiber Concrete In The Subway Station

At present, subway have becoming the important means to solve the traffic problems in the modern cities as the advantages of safe,comfortable,fast etc. But subway stations always have leakage problems in practice. The existence leakage water endangers operators and equipments of the subway, and shorts the service life of concrete structures. Research shows that concrete crack is one of the main reasons caused leakage of subway station. So how to improve concrete cracking resistance and ductility became one of researchers'key fields. And then how to solve the leakage of large concrete slab in subway station have the value of theoretical and projects.The permeability grade and penetration depth, which are only suitable to untracked concrete and not suitable to cracked concrete. So the paper takes the nature permeability method and permeability coefficient as index assessing the permeability of cracked concrete specimens. The result indicates that water permeability reduced with time. Concrete permeability increased with crack width, the degree of the permeability increase depends on the value of crack width in concrete.From the in-suit experiment, design the test project: dividing the subway station into dissimilarity test district, in each inner wall of the test district, embedding the quantity of the vws-10 Vibration string concrete strain meter. Test the temperature trend in different season of the subway station, and the crack development process with different temperature drop load.Then, analyze the diagraph data of the temperature and strain and investigate the crack of each construction segment. Polypropylene fibers lessen the crack and play a role of anti-cracking and waterproof in concrete.