What should we pay attention to when using polypropylene fiber
Polypropylene fiber is widely used, and we are more and more familiar with it. It has become an essential building material in the field of construction engineering! Then, for the construction of large-scale projects, how to control the amount of polypropylene fiber?
1, it is appropriate to select monofilament fiber with fine equivalent diameter for crack resistance and impermeability fields such as mortar putty, and determine the reasonable fiber length according to the particle size of aggregate. A larger aspect ratio is conducive to the reinforcement and toughening of fiber, and a smaller aspect ratio is conducive to the dispersion of fiber. The fiber length for putty is generally 3 mm, and the fiber for mortar is 5-10 mm. When the particle size of mortar sand is 5 mm, the fiber of 12-25 mm can be selected, and when the particle size of concrete stone is 20 mm, the mesh fiber of 19-55 mm can be selected.
2, when using, the fiber is added into the mixer with the aggregate at the same time, but it is necessary to prevent the fiber from gathering between the mixing blade and the baffle to block. Generally, the mixing time is slightly prolonged. The addition of coarse aggregate is conducive to the dispersion of fibers. The impact of aggregate will tear and open the elastic mesh fibers into a disorderly distributed single fiber, but too long mixing time will affect the fiber strength.
3, the addition of fiber will reduce the slump and expansion of concrete. If the slump cannot meet the construction requirements, plasticizer or water reducer should be appropriately used to improve the slump to meet the construction requirements.
4, Construction and maintenance are like ordinary concrete, with no special requirements.
5, it cannot be used as a structural reinforcing material, and cannot replace the structural reinforcing material to be used alone to solve the settlement and crack resistance under the impact of strong external forces.
