Low-shrinkage high-crack-resistance ultra-high performance concrete and preparation method thereof

Abstract

The invention discloses low-shrinkage high-crack-resistance ultra-high performance concrete and a preparation method thereof. The concrete is prepared from the following components in parts by weight: 400 to 500 parts of cement, 150 to 200 parts of silica fume, 400 to 500 parts of stone powder, 750 to 800 parts of fine sand, 200 to 250 parts of coarse sand, 150 to 180 parts of fiber, 33 to 40 parts of a water reducing agent, 190 to 200 parts of water and 40 to 60 parts of and expanding agent. The preparation method comprises the following steps: pouring cement, silica fume, stone powder and an expanding agent into a concrete stirring pot, and uniformly stirring; adding fine sand and coarse sand, and uniformly stirring; pouring 50% of water and a mixture of the residual water and a water reducing agent, and stirring until slurry is formed; continuously stirring the slurry, and slowly adding steel fibers; and pouring, vibrating and forming, covering the surface with a film, removing the mold after one day, and carrying out standard curing to obtain the low-shrinkage high-crack-resistance ultra-high performance concrete. The prepared low-shrinkage high-crack-resistance ultra-high performance concrete is good in working performance and simple in preparation method, reduces pollution, and further has good economic benefits and engineering application value.

Description

technical field [0001] The invention belongs to the technical field of building materials, and in particular relates to a low-shrinkage, high-crack-resistant ultra-high-performance concrete and a preparation method thereof. Background technique [0002] Ultra-high performance concrete (UHPC) refers to a new type of cement-based building material with ultra-high strength (compressive strength ≥ 150MPa), high durability and high toughness. According to the principle of close packing, UHPC improves the gradation of particles, reduces internal defects, and improves the compactness and uniformity of materials by removing coarse aggregates and using fine sand of about 1mm as aggregates; using silica fume, fly ash and The pozzolanic effect and filling effect of mineral powder and other active mineral admixtures improve the pore structure of the material; through the use of polycarboxylate high-efficiency water reducer, the water-binder ratio is greatly reduced, and the porosity is ...

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Problems solved by technology

[0005] At present, UHPC is mainly used in small-sized concrete products such as architectural decorations, steel-UHPC composite bridge deck pavement, and pre

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