A chemical admixture to improve the performance of concrete expansion agent under limited conditions

Abstract

The invention provides a chemical admixture capable of improving the effectiveness of a concrete expanding agent under a restrictive condition. The chemical admixture accounts for 0.1-0.5% of the total weight of the concrete expanding agent, and the concrete expanding agent comprises the rest components as follows: 20.0-50.0% of calcium oxide clinker, 10.0-30.0% of gypsum and 20.0-50.0% of fly ash. The chemical admixture has the benefits as follows: when the adding amount of the chemical admixture is the same, the effect of the concrete expanding agent in a cement-based material under a free condition is remarkably improved and the free expanding rate is increased; the effect of the concrete expanding agent in the cement-based material under the restrictive condition is remarkably improved and the effective expanding rate is increased, so that the chemical admixture is more suitable for a sidewall, a roof and other solid structures with relatively strong constraints; mechanical properties and durability of the cement-based material are slightly affected, so that actual control and use are facilitated.

Description

technical field [0001] The invention relates to a chemical admixture for improving the performance of a concrete expansion agent under restricted conditions, which can increase the limited expansion rate of the expansion agent under strong constraints in engineering practice, and is especially suitable for side walls, roofs, etc. that are poured with shrinkage-compensating concrete. Strongly restrained solid structure, which is beneficial to compensate shrinkage and crack resistance. Background technique [0002] Due to the low water-binder ratio, the extensive use of mineral admixtures, and the compact structure of modern concrete, it is easy to shrink and crack in large quantities during the construction period, which seriously affects the performance of the structure. Judging from the existing research results and engineering practice, shrinkage-compensated concrete is one of the better means to solve the problem of shrinkage cracking of large-volume, large-area and super...

AI Technical Summary

Problems solved by technology

[0016] These methods have a certain effect on improving the expansion performance of the expansion agent, but often have limited effects, and make the production process too complicated, with redundant links, greatly increasing the difficulty of quality control and production energy consumption, which does not meet the national low-carbon environmental protection policy. Industrial policy, and in terms of economic benefits, its actual effect is often not as direct and simple as increasing the amount of expansion agent

Images