Low-frequency vibrating compacted shrinkage-compensating concrete and preparation method thereof

Abstract

The invention relates to low-frequency vibrating compacted shrinkage-compensating concrete and a preparation method thereof. The low-frequency vibrating compacted shrinkage-compensating concrete comprises a cementing material, an expanding agent, a sand material, a stone material, water and a water reducing agent, wherein the expanding agent and the cementing material are in the weight percentageratio of 1 to (5.0 to 15.0) percent; the expanding agent comprises a calcium sulphoaluminate expanding agent and an additive; the additive and the calcium sulphoaluminate expanding agent are in the weight percentage ratio of 1 to (1.0 to 3.0) percent; the additive is one or two of NaAlO2 and KAlO2; the cementing material comprises cement and an active admixture; the active admixture is a compositemineral admixture which consists of coal ash and zeolite powder; the preparation method of the low-frequency vibrating compacted shrinkage-compensating concrete comprises the following steps: (1) adding the sand material, the stone material, the cementing material and the expanding agent into a stirring machine in sequence according to the using amounts above; (2) preparing the water reducing agent and the water into a solution according to the using amounts above, adding a water reducing agent solution into the stirring machine at a uniform speed, and stirring uniformly; and (3) pouring theuniformly stirred concrete on a vibrating mould table, and vibrating for 2 minutes at a low frequency.

Description

technical field [0001] The invention relates to the technical field of concrete, in particular to low-frequency vibrating compact and shrinkage-compensating concrete. Background technique [0002] Prefabricated buildings are the main trend in the development of the construction industry, and the main structural form of prefabricated buildings is prefabricated concrete structures. The connection between prefabricated components in the precast concrete structure will bring a lot of post-cast concrete. If ordinary concrete is directly poured, the ordinary concrete will inevitably shrink, and even lead to cracking in severe cases, affecting structural safety. At present, expansion agents are generally added to ordinary concrete, and the expansion effect produced by the expansion agent is used to compensate the shrinkage of ordinary concrete, so as to produce concrete with stable volume. [0003] However, after the expansion agent is added to the existing ordinary concrete, the ...

AI Technical Summary

Problems solved by technology

[0005] (2) The expansion agent has an important influence on the compactness and hydration products of the concrete. The hydration of the expansion agent usually occurs in the early stage. The early expansion rate is fast and the stability is poor, which may lead to insufficient hydration water of the cement particles in the later stage. If the water is not replenished in time, The hydration will stop, but the drying shrinkage will continue, and the strength will not increase, causing cracks to occur in advance

Images