Concrete expanding agent and preparation method and application thereof

Abstract

The invention discloses a concrete expanding agent and a preparation method and an application thereof. The concrete expanding agent comprises the following raw materials in parts by weight: 25-30 parts of anhydrite, 5-10 parts of aluminum sulfate, 12-25 parts of calcium oxide, 3-5 parts of a delayed coagulant, 8-15 parts of a water reducer, and 16-35 parts of fly ash. The above raw materials areweighed according to the above ratio, and crushed and stirred to prepare the concrete expanding agent. The concrete expanding agent can be widely used in a preparation process of various concretes, and the addition proportion is 6-8%. Compared with the prior art, the concrete expanding agent has good functions for water reducing, enhancement, slump retaining and crack resisting; and is especiallysuitable for preparing the high-performance shrinkage-compensating concrete, the large-volume crack-resistant concrete or the special concrete having expansion requirements in super-length structure engineering.

Description

technical field [0001] The invention relates to the technical field of concrete and mortar, in particular to a concrete expansion agent and its preparation method and application. Background technique [0002] Concrete will shrink in volume during the initial setting or hardening process, and shrinkage stress will be generated inside the structure. When the shrinkage stress exceeds the concrete tensile strength, it will cause the concrete to crack and form shrinkage cracks. In order to prevent and alleviate the temperature shrinkage cracks of super-long concrete structures, it is a routine measure to effectively install post-casting belts, but the post-casting belts prolong the construction period, and the overlapping, welding and cleaning of broken steel bars will bring some troubles to the joint filling construction. If it is not handled properly, it will leave hidden dangers. Expansion agent is a kind of material that can cause volume expansion through physical and chemi...

AI Technical Summary

Problems solved by technology

However, the concrete expansive agents in the prior art are often due to low expansion rate or insufficient compensation for shrinkage, which cannot adapt to the development of concrete strength, resulting in inability to simultaneously compensate for concrete shrinkage or insufficient strength to easily cause slump, etc., resulting in poor construction results

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