Polypropylene coarse fiber for concrete and method for preparing same

Abstract

The invention relates to concrete used polypropylene coarse fiber and a preparation method thereof. The diameter or the equivalent diameter of a filament ranges from 0.08mm to 1.5mm with the corresponding titer of 40 to 14200 deniers, the fracture strength of more than 450MPa, the elastic modulus of more than 5000MPa and the breaking elongation of 10 percent to 30 percent. In the preparation method, polypropylene and the components of the polypropylene coarse fiber are dried to the extent that the weight is kept constant before the polypropylene and the components are mixed uniformly; after the mixture is extruded by the spinning die of a double screw extruder, the mixture is cooled in a water bath; subsequently, the mixture is graded and stretched for a plurality of times at the temperature higher than the glass transition temperature of polypropylene; on completion of the stretching, ordinary polypropylene spinning used oil solutions with the weight concentration of 5.0 percent are applied on coarse fiber bundles for thermoforming before the surface of the fiber is indented; finally, the fiber is cut and packaged according to required length. By adopting the concrete used polypropylene coarse fiber, the interface of the course fiber and a basal body has good acting force, thus improving the anti-cracking, the impermeability, the fold resistance, the toughness, the shock resistance, the freeze and melt resistance, the fire resistance, and the blast resistance of coarse fiber reinforced concrete.

Description

technical field [0001] The invention relates to a polypropylene fiber and a preparation method thereof, in particular to a polypropylene crude fiber for concrete and a preparation method thereof. Background technique [0002] Concrete is a widely used and very important building material, and is currently developing in the direction of high performance, functionality, and high durability. However, the inherent disadvantages of concrete, such as low tensile strength, high brittleness, poor toughness, and poor resistance to deformation, restrict its development and application. In recent decades, the use of synthetic fibers to strengthen concrete can achieve the purpose of improving its anti-crack and anti-seepage performance, optimizing mechanical properties, and improving freeze-thaw resistance. [0003] Synthetic fibers have been widely used in concrete. Due to the reduction or elimination of cracks, the integrity of the mortar concrete structure is maintained, and its dur...

AI Technical Summary

Problems solved by technology

However, there are still certain limitations in improving the dispersion and improving the interface between fibers and substrates only by physical methods or adding hydrophilic polymers: the interface between fibers and substrates cannot be fully filled with hydration products , the presence of hydrophilic polymers will cause water film aggregation at the interface, which will cause the water-cement ratio to be too large, which will increase the porosity accordingly, thus affecting the strengthening and toughening effect of the fiber