Polymer coarse fibre used for concrete and preparation method

Abstract

The invention relates to a polymer coarse fibre used for concrete and a preparation method. The polymer coarse fibre is cylindrical, and the surface of the coarse fibre is provided with more than one anchored sheet distributed along the axial direction. The preparation method comprises the following steps: after polymer is dried to constant weight, adding the polymer to a twin-screw extruder; after the polymer is extruded by a spinneret plate hole, cooling a strand; then, stretching by stages for times at the temperature higher than the polymer vitrification temperature; after stretching is finished, cutting the anchored sheet on the surface of the strand; then, carrying out heat setting; and finally cutting off and packaging to obtain the polymer coarse fibre. In the preparation method, the appearance shape of the fibre is changed, so that the coarse fibre and a matrix have good interfacial bonding force, and therefore the cracking resistance, bending resistance, toughness and impact resistance of the coarse fibre enhanced concrete are enhanced or improved.

Description

technical field [0001] The invention relates to a polymer crude 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 very important building material, which is currently being developed 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, thereby re...

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

Images