High-strength concrete composite expanding agent for steel tube and preparation method thereof

Abstract

The invention relates to a high-strength concrete composite expanding agent for a steel tube and a preparation method thereof. The high-strength concrete composite expanding agent comprises the raw material by weight percentage as follows: 30-50% of light calcined magnesium oxide, 8-30% of calcium oxide, 30-60% of zeolitized crushed crude pearlite, and 0.1-0.3% of industrial stearic acid. The water demand for hydration of light calcined magnesium oxide is small in use level, and the light calcined magnesia has the delayed expansion performance and can compensate volume shrinkage of concrete at an older age. The calcium oxide is fast to hydrate and can compensate self-shrinkage and cooling shrinkage of concrete in an earlier stage. The zeolitized crushed crude pearlite can improve the working performance of concrete, so that concrete has good peaceability, and calcium oxide and magnesium oxide expanding components are distributed uniformly in the concrete, so that the problem of nonuniform expansion of concrete is solved. The high-strength concrete composite expanding agent is stable in long-term expansion performance, and expansion and shrinkage as well as strength are in synergetic development. The water required for expansion is little, concrete in a sealed state expands continuously and stably, and the working performance of concrete can be improved. The high-strength concrete composite expanding agent is particularly suitable for preparing steel tube concrete.

Description

technical field [0001] The invention relates to a concrete expansion agent, in particular to an expansion agent for steel tube concrete and a preparation method thereof. Background technique [0002] With the popularity of super high-rise buildings, CFST has been widely used due to its excellent cost performance. The key technology of steel pipe concrete is to add expansion agent to compensate the shrinkage of concrete, so that it can be closely combined with the steel pipe wall. Various existing steel pipe expansion agents have various problems in the application process, mainly including the following: [0003] (1) The long-term expansion performance of concrete is unstable. The existing expansion agent hydrates quickly, and it is difficult to realize the coordinated development of expansion, shrinkage and strength of concrete. [0004] (2) The hydration of the expansion agent requires a large amount of water. Most of the concrete filled steel tubes are high-strength c...

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Problems solved by technology

[0007] The invention provides a steel pipe high-strength concrete composite expansion agent and a preparation method thereof, which solve the technical problems of the existing steel pipe expansion agent such as unstable long-term expansion performance, uneven expansion, large water demand for hydration, and affecting the workability of concrete

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