A kind of ultra-high performance fiber concrete of C220 strength grade containing coarse aggregate and its preparation method

Abstract

The invention discloses a C220 ultra-high-performance fiber concrete containing coarse aggregate and a preparation method thereof. The mass parts of the concrete are as follows: 545 parts of cement, 63 parts of water, 900 parts of crushed stone, fine aggregate 750 parts, 72 parts of fly ash, 65 parts of rice husk ash, 140 parts of silica fume, 15.5 parts of water reducing agent, 11.5 parts of activator, 1.7 parts of cellulose fiber, 78 parts of steel fiber, hydroxyl modified carbon nanotube dispersion 48 parts, 50 parts of graphene oxide dispersion, 2.9 parts of defoamer. The prepared concrete has high toughness and durability, and has a high bond strength with the steel, with a compressive strength of 224.31MPa, a flexural strength of 47.45MPa, and a splitting tensile strength of 22.37MPa. The bonding strength reaches 8.92MPa, and the chloride ion impermeability level reaches level VI. Used in steel-concrete composite structures, it can effectively exert the synergistic performance between steel and concrete, make up for the poor bonding performance of steel and concrete, and the inability to give full play to their respective mechanical properties.

Description

technical field [0001] The invention belongs to the field of new building materials, and is a high-strength, high-toughness and high-durability superhigh-strength building material containing coarse aggregate mixed with rice husk ash, cellulose fiber, steel fiber, modified carbon nanotube and graphene oxide. The performance concrete particularly relates to an ultra-high-performance fiber concrete with high toughness and a C220 strength grade containing coarse aggregate 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 ...

AI Technical Summary

Problems solved by technology

[0005] In the existing research, the ultra-high performance concrete containing coarse aggregate is obviously brittle and has poor deformation resistance, which limits the application of this type of concrete in actual engineering. On the basis of performance, improve the strength of concrete and greatly improve the toughness of concrete, and prepare ultra-high performance fiber concrete with compressive strength above 200MPa, containing coarse aggregate, high toughness and ultra-high durability

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