PVA fiber for fiber reinforced concrete
Writer： admin Time：2023-11-01 16:32 Browse：
Fiber reinforced concrete (FRC) is a composite of fiber and concrete. Because concrete has the disadvantages of low tensile strength, poor ductility and high brittleness, adding fiber can improve its mechanical properties such as tensile strength, impact strength, bending resistance and ductility. Among them, polyvinyl alcohol fiber (PVA fiber) can not only improve the ability of cement brittle substrate to resist crack development, but also significantly reduce the brittleness of concrete, increase ductility and toughness, and meet the material requirements in future projects. The flexural toughness test of polyvinyl alcohol fiber concrete is carried out. It is found that the addition of polyvinyl alcohol fiber can significantly improve the flexural toughness of concrete to a certain extent.
By adding polyvinyl alcohol fiber (PVA fiber)and polypropylene fiber to improve their impact resistance, and controlling the content and length of polyvinyl alcohol fiber and polypropylene fiber, the following relevant conclusions are obtained:
(1) For polyvinyl alcohol fiber, with the increase of fiber length, the greater the displacement of concrete specimen during impact, shorter fiber should be selected. In this paper, the best impact resistance effect of polyvinyl alcohol fiber concrete is that the fiber length is 6mm; For polypropylene fiber, with the increase of fiber length, the displacement of concrete specimen during impact first decreases and then increases, and there is the best value between 6-12mm. In this paper, the best impact resistance effect of polypropylene fiber concrete is that the fiber length is 9mm.
(2) The optimum content of polyvinyl alcohol fiber concrete and polypropylene fiber concrete is 2kg / m3. However, from the later experimental results, it is not that the greater the fiber content, the better the impact resistance of concrete, but there is an upper limit of fiber content.
(3) Based on the time displacement curve and time pseudo resultant force curve, it can be concluded that the impact resistance of polypropylene fiber is more obvious than that of polyvinyl alcohol fiber.
(4) In addition, from the perspective of maximum displacement and maximum pseudo resultant force, it can be seen that the impact resistance of concrete can be improved most obviously when 1kg / m3 polyvinyl alcohol fiber and 1kg / m3 polypropylene fiber are added at the same time.
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