Polypropylene fiber is a high-strength polypropylene staple fiber, treated with special surface technology to ensure its dispersion in concrete and its grip on the cement matrix. Generally used in fine aggregate concrete. Concrete fibers (recommend using 12-19mm concrete fibers for their high tensile strength and excellent crack resistance.) with a tensile strength of over 500 MPa, elongation at break of 15-25%, and an elastic modulus greater than 3800 MPa.
1. Significantly enhance the crack resistance of mortar and concrete. Experimental evidence shows that compared to regular mortar/concrete, the addition of a single fiber with a volume fraction of 0.1% (approximately 0.9 Kg/m3) boosts the crack resistance by 70%.
2. Significantly enhances the impermeability of concrete. Concrete mixed with 0.9 Kg/m3 of polypropylene staple monofilament fiber has an impermeability improvement of 60% to 70% compared to regular concrete.
3. Significantly enhanced the impact resistance and wear resistance of concrete. Although polypropylene fibers have low stiffness and poor load transfer capabilities, they can absorb impact energy, effectively reduce cracking, and strengthen the continuity of the matrix material. This reduces the local stress concentration caused by the blockage of shock waves, thereby greatly improving the concrete's impact resistance and toughness.
4. Enhance the concrete's frost resistance. The addition of polypropylene fibers to concrete can alleviate the internal stresses caused by temperature changes, preventing the expansion of temperature cracks; at the same time, the improvement in the concrete's impermeability also benefits its frost resistance. Both practice and research demonstrate that incorporating polypropylene fibers into concrete can serve as an effective means of concrete temperature difference compensation and crack prevention.
5. Enhance the quality of concrete products, effectively maintaining the integrity of edges, corners, and surfaces, thereby preventing corrosion of the steel reinforcement inside. Mortar fibers (it is recommended to use sand with a particle size of 3-12mm) have good dispersion and tensile properties, effectively preventing balling. The performance of mortar fibers: The main purpose of adding fibers to mortar is to impart certain flexibility, improve the mortar's crack resistance, and inhibit the formation of early cracks. The main functions include:
(1) Prevents crack propagation, effectively halting the expansion of existing defects within the mortar matrix and delaying the appearance of cracks.
(2) Waterproofing: Enhances the compactness of the mortar matrix to prevent external moisture intrusion.
(3) Enhanced durability, improved frost and fatigue resistance of the mortar matrix, and increased longevity.
(4) Impact Resistance: Enhances the砂浆matrix's ability to withstand deformation, thereby improving its toughness and impact resistance.
(5) Tensile Strength: Utilizing fibers can enhance the tensile strength of the matrix.
(6) High Tensile Strength: The mortar fiber boasts high tensile and strength properties, making it less prone to bending into balls during mortar mixing. The meshed polypropylene fiber has a net-like structure formed by intertwining numerous single fibers. Upon incorporating the polypropylene mesh fiber into concrete, during the mixing process, the lateral connections between the fiber strands are broken down due to the concrete's own rubbing and friction actions, resulting in the full expansion of the individual fiber strands or the net-like structure. This allows for a uniform distribution of a large number of polypropylene fibers throughout the concrete.
