A kind of super high strength concrete and preparation method thereof

Abstract

The invention discloses an ultra-high-strength concrete, which comprises the following components in parts by weight: 300-350 parts of cement, 270-315 parts of composite mineral admixture, 30-35 parts of composite expansion agent, 96-35 parts of water 112 parts, 680~720 parts of river sand, 1012~1080 parts of gravel, 13.2~14.0 parts of polycarboxylate superplasticizer, 4.4~4.7 parts of plastic retaining agent, 0.18~0.21 parts of defoamer; the composite mineral The admixture consists of 42-49 parts of mineral powder, 150-175 parts of fly ash, 30-35 parts of silica fume, 18-21 parts of zeolite powder and 30-35 parts of wollastonite powder. The present invention is characterized in that the compressive strength of concrete at 60 days is 140-160 MPa, the splitting tensile strength at 60 days is 9.2-10.2 MPa, the self-compacting effect can be achieved within 3 hours after leaving the machine, and the self-shrinkage value at 14 days is less than 5 / 10,000.

Description

technical field [0001] The invention belongs to the technical field of building materials, and in particular relates to an ultra-high-strength concrete and a preparation method thereof. Background technique [0002] In recent years, high strengthening has become one of the trends in the development of modern concrete technology. The research and development of high-strength concrete has made great progress. The strength of high-strength concrete has gradually increased, its performance has been continuously improved, and it has been widely used in many fields. However, with the complexity of building structures and the increasing number of super high-rise buildings, high-strength concrete can no longer meet the needs of construction, and ultra-high-strength concrete will become the most important trend in the development of concrete. All countries in the world have begun to conduct theoretical research and engineering applications on ultra-high-strength concrete. [0003] ...

AI Technical Summary

Problems solved by technology

[0004] Although ultra-high-strength concrete has many advantages, it also has some disadvantages due to its own characteristics; The shrinkage of high-strength concrete is large, which can reach more than ten thousandths, and it mostly occurs in the early age, resulting in a higher probability of early cracking than ordinary concrete; on the other hand, as the compressive strength of concrete continues to increase, its brittleness gradually increase, which to some extent restricts the application of ultra-high-strength concrete in engineering

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