A kind of concrete with c250 strength grade for steel-concrete composite structure

Abstract

The invention discloses concrete for the steel reinforced concrete composite structure C250 strength grade. The matching ratio of cement to fine aggregate to coarse aggregate to water to water reducing agent to antifoaming agent to silica powder to coal ash to exciting agent to expanding agent to composite plastic retaining agent is 504:769:1,308:102:21:1.5:100:125:11:52:0.65. A preparing method includes the steps that the water reducing agent, the exciting agent and the composite plastic retaining agent are evenly stirred into water to obtain a mixture, and the fine aggregate and 1 / 3 of the total mixture are sequentially added into a stirring machine according to the weight ratio and stirred to be even; the coarse aggregate and 1 / 3 of the total mixture are added and stirred to be even; the cement, the expanding agent, the silica powder and the coal ash are added and stirred to be even; the antifoaming agent and the residual mixture are added, and the mixture is stirred and discharged. By means of the concrete, the bonding performance between structural steel and the concrete can be remarkably improved under the natural state, the mechanical performance and the cooperative work performance of the steel and the concrete are effectively developed, the carrying capacity, the use performance and the durability of a structural element are greatly improved, and the concrete has the good high volume stability and the good economy.

Description

technical field [0001] The invention belongs to the technical field of building materials, and relates to an ultra-high-strength and high-performance concrete with a strength grade of C250 for steel-concrete composite structures. Background technique [0002] The invention of Portland cement in 1824 led to the rapid development of concrete technology. Its consumption is large and its scope of application ranks the highest in the world. Although concrete is a traditional man-made building material, because of its irreplaceable advantages (abundant raw materials, simple production process, high cost performance, etc.) and the continuous progress of concrete material science and technology, concrete has become the main body of civil engineering materials. , It will also be one of the indispensable main materials in future civil engineering and national construction. At the same time, with the continuous expansion of the city, the continuous increase of the population, the cont...

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Problems solved by technology

[0005] The strength grades of concrete used for steel-concrete composite structures in the prior art include low-strength high-performance concrete of C30, C35, C40, C45, C50 and C55, high-strength high-performance concrete of C60, C70, C80, C90 and C100, and C110, C120, C130, C140, and C150 ultra-high-strength high-performance concrete, as well as the preparation technology of C160, C170, C180, C190, and C200 ultra-high-strength high-performance concrete. ) between the high-strength concrete, and improve the durability of the structure; however, there are still ultra-high-strength high-performance concrete that cannot be extended to higher strength, and when it is used in steel-concrete composite structures, it cannot solve the problem of steel The problem of poor natural bonding performance with ultra-high-strength and high-performance concrete, so it cannot meet the requirements of civil engineering buildings extending to the air, underground and water, that is, super / ultra-high buildings, super / ultra-large spans, underground, sea or Underwater, ultra-durable and heavy, giant and novel structural engineering and other applications and development trends

In addition, in the prior art, there are also some preparation technologies for super / ultra-high strengthening and super / ultra-durability of concrete, but none of them involve or solve the natural relationship between section steel and ultra-high-strength high-performance concrete when used in SRC structures. The problem of poor bonding performance

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