Use of Polypropylene Fiber in Concrete

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Polypropylene fiber after a special anti-static and anti-ultraviolet treatment, the fiber in the concrete dispersion, can play its long-term effect; polypropylene fiber "Y" cross-section increases the fiber surface area; fiber after chemical and physical modification, surface rough porous, greatly improving the fiber and cement-based aggregateBinding force.
Main advantages of polypropylene fiber:
1) Good dispersion, strong grip;
2) High acid and alkali resistance, high radiation resistance;
3) frost resistance, corrosion resistance, strengthening and toughening;
4) Physical reinforcement, crack resistance reinforcement;
5) Stable performance, safe and non-toxic;
6) Simple construction, economical and reliable;
The superior performance of PP fiber:
1. Improve anti-cracking performance;
2. Improve impermeability;
3. Improve the impact resistance and wear resistance;
4. Improve frost resistance;
5. Increased resilience;
6. Increase the fire resistance of the product and improve the anti-explosion function;
7. Improve the quality of products.
Polypropylene fiber in concrete mainly has the following uses:
1) to prevent plastic shrinkage cracks in concrete. In the process of setting and hardening of concrete, surface water loss will lead to plastic shrinkage and cracks. Concrete mixed with polypropylene fiber can prevent such cracks. Because the elastic modulus of polypropylene fiber is lower than that of hardened concrete, the cracking resistance of hardened concrete (temperaturedegree stress or mechanical load and other effects of cracks) to improve the limited, anti-pull, bending strength is not much, the toughness of concrete has a certain degree of improvement.
2) Improve the fire resistance of hardened concrete. Under the action of high temperature, polypropylene fiber will soften and burn out first, forming many channels in the concrete, and the water vaporized by high temperature in the concrete can be discharged along these channels to prevent the water from vaporizing to form internal high pressure and make the concrete burst, thus greatly improving the mixingFire resistance time and fire resistance rating of concrete.
3) improve the impermeability of concrete: after the incorporation of fiber, it can effectively prevent the segregation of cement concrete and improve the overall uniformity of the pouring body; significantly reduce the number, length and width of cracks, reduce the possibility of forming through cracks, and play a role in blocking the capillary cracks in concrete, so that the resistance of concretePermeability is obviously improved. At the same time, the transfer rate of water, chloride ion and air in concrete is reduced, so as to delay the corrosion of steel.
4) to enhance the toughness of concrete, fatigue resistance, improve the abrasion resistance of concrete: fiber added to the cement matrix, can reduce the brittleness of cement concrete, improve the toughness of the substrate. The cement concrete mixed with fiber can withstand tens of thousands of times, and even millions of times the static strength of the stress repeated action, still maintain a goodThe state. This feature is beneficial to some cement concrete structures (such as roads, sidewalks, pavement covering, warehouse pavement, etc.) that are often subjected to impact fatigue.

Key words:

Polypropylene fiber