Compound admixture for heat curing-free concrete in winter construction

Abstract

The invention discloses a compound admixture for heat curing-free concrete in winter construction. The compound admixture consists of the following components in parts by mass: 28-40 percent of high performance superplasticizer, 3-10 percent of early strength admixture, 5-15 percent of antifreezing agent, 3-7 percent of plant fiber intermediate-acting water-reducing agent MPA for retaining plastic and controlling the thickening, 0.02-0.5 percent of defoaming agent, 0.02-0.1 percent of PC-II for bleeding air and the balance of water. The compound admixture disclosed by the invention can be used for concrete with the intensity of C35 and over C35, does not need heat curing during winter construction and has the addition amount of 1-2 percent of that of gel material; and the compound admixture has the advantages of enabling the concrete to have upper flow regime, favorable cohesiveness, favorable water-retaining property, favorable slump loss, early strength under low temperature, good apparent mass of concrete and the like. According to the compound admixture, the initial slump flow is over 500mm, the early strength is obviously increased without influencing the development of later strength, the template cycle is prolonged and the curing cost of the concrete is reduced.

Description

technical field [0001] The invention belongs to the technical field of concrete admixtures, and relates to a concrete admixture, in particular to a composite admixture for winter construction heat-free curing concrete. Background technique [0002] With the rapid development of our country's social economy, a large number of infrastructure construction, most of the projects have the characteristics of tight construction schedule and heavy tasks, and many projects still have to continue construction in winter. However, the strength development of traditional concrete is slow at low temperature, which significantly prolongs the form removal time, reduces the formwork turnover cycle, seriously affects the construction progress and increases the construction cost. How to ensure both the construction period and the quality of concrete has always been a concern of construction companies. At present, thermal curing is generally used in winter construction of concrete to ensure the...

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Problems solved by technology

[0004] The purpose of the present invention is to overcome the shortcomings of the existing technology of winter construction, that is, the lack of obvious improvement in the early strength of concrete using traditional antifreeze and water-reducing agents at low and negative temperatures in winter or the shortcomings of using heat curing to speed up the progress of the project, and to provide a winter construction method. Composite admixture for construction of heat-free curing concrete. This agent has the characteristics of heat-free curing in winter construction, greatly improving the early and late strength of concrete, and can also improve the workability, stability and durability of concrete.

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