1) Prevent plastic shrinkage cracks in concrete. During the curing and hardening process, the surface water loss of concrete can lead to plastic shrinkage and cracking. Concrete reinforced with polypropylene fibers can prevent such cracks. Since the elastic modulus of polypropylene fibers is lower than that of hardened concrete, the improvement in the crack resistance of hardened concrete (cracking due to temperature stress or mechanical loads, etc.) is limited, and the tensile and bending strength increases are not significant, but there is a certain degree of improvement in the toughness of concrete.

2) Enhance the fire resistance of hardened concrete. Under high temperatures, polypropylene fibers soften and burn first, creating numerous channels within the concrete. The water vaporized by the high temperature in the concrete can then escape through these channels, preventing the formation of internal high pressure due to water vaporization, which could cause the concrete to crack. This significantly increases the fire resistance duration and grade of the concrete.

Enhanced Crack Resistance: The uniformly distributed fibers form a three-dimensional network structure in cement concrete, withstanding tensile stresses caused by water loss and shrinkage during the plastic state of cement concrete, thereby reducing or even preventing the formation of cracks on the concrete surface.

Enhancing Concrete Permeability: The addition of fibers effectively prevents the segregation of cement concrete, improving the overall uniformity of the cast body; it significantly reduces the number, length, and width of cracks, lowering the likelihood of through cracks, and acts as a barrier against capillary cracks within the concrete, thereby notably improving its impermeability. Additionally, it reduces the transfer rates of moisture, chloride ions, and air within the concrete, thereby delaying the corrosion of steel reinforcement.