Composite concrete expanding agent

Abstract

The invention discloses a composite concrete expanding agent, and relates to the technical field of concrete and mortar. The expanding agent is composed of the following raw materials by weight: 60-70parts of quicklime, 12-16 parts of sulfoaluminate cement, 18-24 parts of anhydrite, and 0.4-0.6 part of a water retaining agent. The expanding agent is mainly used for preparing shrinkage-compensating concrete and grouting materials, is used for reducing and eliminating shrinkage cracks of concrete, and has the main characteristics of early expansion, obvious vertical expansion and 24-hour restrained expansion rate of 0.007-0.011%. The restrained expansion rate in three days can reach 0.065 to 0.070%; the dry shrinkage amount is low; after water spraying and curing, the expansion rate can berecovered to 95-100%; the raw materials are easy to obtain and the preparation method is simple. The maintenance condition is simple, water soaking is not needed, only 2-3 times of water spraying is needed every day, and the expansion rate can reach 95% or above of that of concrete maintained in a water storage mode.

Description

technical field [0001] The invention relates to the technical field of concrete and mortar, in particular to a composite concrete expansion agent. Background technique [0002] Expansive agents have been used in concrete engineering for decades, and the main purpose is to solve the problem of shrinkage cracks in concrete. [0003] In the 1980s, UEA expansion agent began to appear on the market, and the expansion rate was 0.025% (7 days in water). Around 2010, an expansion agent with a 7-day expansion rate of more than 0.05% appeared on the market, such as HCSA. This expansion agent has a significant compensation for shrinkage and greatly reduces concrete cracking, but the price is high, and special calcination equipment (rotary kiln) is required for production. ), the HCSA expansion agent raw meal itself also needs ingredients, and after the clinker is fired with a large rotary kiln, it needs secondary ingredients and grinding to make the expansion agent, which is difficult...

AI Technical Summary

Problems solved by technology

[0005] For this reason, the present invention provides a composite concrete expansive agent to solve the problems of existing concrete expansive agents, such as poor early compensating shrinkage effect, small expansion rate after stopping wet curing, and even absolute shrinkage, resulting in cracks in the later concrete structure, high price, and high price. high production requirements

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