A kind of ultra-high-strength high-performance fiber concrete of C200 strength grade and preparation method thereof

Abstract

The invention discloses an ultra-high strength high-performance fiber concrete with a strength grade of C200 and a preparation method thereof. The concrete comprises the following components in parts by mass: 520 parts of cement, 66 parts of water, 990 parts of gravel, 760 parts of fine aggregates, 65 parts of fly ash, 72 parts of rice husk ash, 126 parts of silica fume, 15.6 parts of a water reducer and 10.2 parts of an activator, 1.7 parts of cellulose fibers, 46 parts of a hydroxyl modified carbon nanotube dispersion liquid, 47 parts of a graphene oxide dispersion liquid and 2.8 parts of a defoaming agent. The prepared concrete has high toughness and excellent durability and has high bonding strength with section steel. The compressive strength reaches 207.87 MPa, the breaking strength reaches 37.69 MPa, the splitting tensile strength reaches 18.32 MPa, the bonding strength with section steel reaches 8.75 MPa, and the impermeability grade of chloride ions reaches a VI grade. The concrete provided by the invention is used in a section steel concrete composite structure, the cooperative working performance between the section steel and the concrete can be effectively exerted, and the defects that the bonding property between section steel and concrete is poor and respective mechanical properties of the steel sections and the concrete can not be fully exerted are made up.

Description

technical field [0001] The invention belongs to the field of new building materials, and is a high-strength, high-toughness and high-durability concrete mixed with rice husk ash, cellulose fibers, modified carbon nanotubes and graphene oxide, and specifically relates to a C200 concrete with high toughness Ultra-high-strength high-performance fiber concrete of strength grade and a preparation method thereof. Background technique [0002] Ordinary concrete and cement-based materials have low tensile strength and poor toughness, and a large number of microcracks will be generated during hardening or under external loads, making Cl - , SO 4 2- and other harmful ions and CO 2 Harmful gases such as gas invade the interior of the concrete, accelerate the erosion of the concrete structure, seriously affect the durability of the concrete or cement-based composite structure, and reduce the service life of the structure. [0003] Carbon nanotube is a one-dimensional fiber material ...

AI Technical Summary

Problems solved by technology

However, due to the sp2 hybrid structure in the graphene plane, there is a strong molecular attraction between the nanoparticles, which causes mutual adsorption, causing the graphene to agglomerate together, unable to stably disperse in the polymer and play its role, and even cause the occurrence of defect

The oxidized graphene monolithic surface introduces a lot of oxygen-containing functional groups such as hydroxyl and carboxyl, so that it can be uniformly dispersed in water, but graphene oxide is prone to flocculation under alkaline conditions, which is very difficult for graphene oxide in cement. Dispersion is unfavorable and may even cause loss of concrete strength

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