Coarse fiber for concrete and preparation method of coarse fiber

Abstract

The invention relates to a coarse fiber for concrete, which is in a shape formed by spirally twisting a polygonal prism along the axial direction, wherein the length of the coarse fiber is 20-60 mm and the diameter or the equivalent diameter of the section is 0.10-1.20 mm; and the surface between adjacent edges is concave. The preparation method comprises the following steps of: drying preparation materials of the fiber to constant weight and adding the materials into a double-screw extruder; after extruding through a spinneret plate hole, cooling filaments by utilizing cooling liquid; then connecting the filaments into a guide wire hole plate which is the same as the spinneret plate hole in shape and is rotated for an angle; carrying out grading multi-time stretching on the filaments of the guide wire hole plate; after the stretching is finished, carrying out heat setting; and then, cutting according to the length and packaging to obtain the product. According to the invention, through changing the appearance and the shape of the fiber, a good interface acting force exists between the coarse fiber and a substrate and the rigidity of the fiber is increased, so as to enhance or improve the performance of the coarse fiber in enhancing the anti-cracking, anti-breaking, tough, anti-impact properties and the like of the concrete.

Description

technical field [0001] The invention relates to a polymer fiber and a preparation method thereof, in particular to a polymer crude fiber for concrete and a preparation method thereof. Background technique [0002] Concrete is a widely used and very important building material, which 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, people have used synthetic fibers to strengthen concrete to improve its anti-crack and anti-seepage performance, optimize its mechanical properties, and improve its 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 durability is improved, there...

AI Technical Summary

Problems solved by technology

[0006] From the modification methods listed above, it can be seen that the modification methods are divided into chemical methods and physical methods. The chemical method is mainly to improve the interface between the fiber and the substrate by adding hydrophilic polymers, but there are certain limitations. Properties: The interface between the fiber and the substrate 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, and the porosity will increase accordingly, thus affecting the fiber. The strengthening and toughening effect, and the addition of other components to the polymer will increase the difficulty of molding and processing, and will also reduce its mechanical properties to a certain extent

When the fiber bears the load in the matrix, it usually improves the impact resistance and toughness deformation ability by means of pulling out and sliding energy consumption. The rough surface of the prior art is mostly surface indentation, and the special-shaped cross-section is to increase the contact between the fiber and the matrix. Contact area, these types of thick fibers experience the same stroke after debonding from the matrix, so they have limited effect on anchoring and sliding energy dissipation after debonding

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