Preparation method of surface hyperbranched modified steel fiber and ultra-high performance concrete based on modified steel fiber

Abstract

The invention discloses a preparation method of surface hyperbranched modified steel fibers and ultra-high performance concrete based on the modified steel fibers. The preparation method of the surface hyperbranched modified steel fiber comprises the steps that pretreated steel fiber is placed in silane coupling agent hydrolysate for a reaction, and silane coupling agent modified steel fiber is obtained; and placing the silane coupling agent modified steel fiber in a mixed solution of tetraethoxysilane, absolute ethyl alcohol and deionized water to obtain the surface hyperbranched modified steel fiber. Hyperbranched modification is carried out on the surface of the steel fiber through the method, the corrosion resistance is improved, meanwhile, multidirectional matrix embedding and cohesiveness strengthening are achieved, the toughening, strengthening and crack resisting performance of the steel fiber on the UHPC is improved, the cost is low, the operation method is simple, toxicity is avoided, harm to the environment is avoided, and batch treatment can be carried out on materials.

Description

technical field [0001] The invention relates to the field of building materials, in particular to a preparation method of a surface hyperbranched modified steel fiber and an ultra-high performance concrete based on the modified steel fiber. Background technique [0002] Ultra-high performance concrete (UHPC) is a new generation of cement-based composite materials with excellent mechanical properties and good durability. It has been widely used in high-rise buildings, long-span bridges, marine engineering, hydraulic engineering, nuclear power engineering and special structures. Steel fiber is an important component in the preparation of UHPC toughening and strengthening. However, in order to prevent the corrosion of steel fibers, the steel fibers are usually plated with copper to make the surface of the steel fibers smooth. There is generally no chemical interaction between the currently used steel fibers and the UHPC matrix, and the interfacial bonding strength only depends...

AI Technical Summary

Problems solved by technology

To improve the bonding strength between steel fiber and matrix, methods such as surface shaping and surface etching are generally used, but it is easy to cause the loss of steel fiber tensile strength.

For example, the most common chemical treatment method is to treat the surface of steel fibers with zinc phosphate, but the heavy metals in zinc phosphate pollute the environment, and the energy consumption is high, making it difficult for this method to achieve toughening and strengthening the interface between steel fibers and UHPC. widely used

It is difficult to fundamentally solve the problem of poor adhesion between steel fibers and the matrix by physically etching or adsorbing nanoparticles to improve the surface roughness of steel fibers to improve their adhesion to the matrix.