High-performance polycarboxylic acid water reducer and special compound admixture containing the water reducer for limestone powder concrete

Abstract

The invention relates to a high-performance polycarboxylic acid water reducer and a special compound admixture containing the water reducer for limestone powder concrete. The special compound admixture for limestone powder concrete comprises a high-performance polycarboxylic acid water reducer I 5 to 10wt%, a high-performance polycarboxylic acid water reducer II 10 to 15wt%, retarder 1 to 5wt%, defoamer 0 to 0.2wt%, air entraining agent 0 to 0.1wt%, and water 70 to 80wt%, wherein the sum of mass percents of every component is 100%. The admixture provided by the invention can effectively improve workability of fresh limestone powder concrete, and can prevent 3-hour work performance loss of fresh limestone powder concrete without influencing concrete strength development. The admixture preparation method is unique, simple and feasible, and is suitable for large-scale industrial production.

Description

technical field [0001] The invention relates to a concrete admixture, in particular to a polycarboxylate high-performance water reducer and a special composite admixture for limestone powder concrete containing the same. Background technique [0002] In recent years, with the rapid development of the domestic construction industry, the demand for concrete has been increasing year by year, and the supply of traditional mineral admixtures has been in short supply. With the adjustment of the national energy strategy and the development and progress of the electric power field, thermal power generation will decrease year by year, and the fly ash resources will inevitably become increasingly scarce. Limestone is the most readily available, easy-to-grind, and low-cost material. Grinding it into limestone powder to replace conventional mineral admixtures such as fly ash is an inevitable development trend in the concrete industry in the future. [0003] Although limestone powder h...

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Problems solved by technology

[0003] Although limestone powder has a good application prospect in ready-mixed concrete, limestone powder also brings some new problems to concrete: the water retention of limestone powder particles is poor, and it is easy to produce bleeding when the amount of limestone powder is added to the concrete. Water phenomenon; limestone powder is easy to cause the loss of concrete work performance too quickly, so it is not used in engineering construction; due to the difference in limestone material, some limestone powder has a greater impact on the work performance of concrete, resulting in a substantial increase in the amount of concrete admixtures, which is not conducive to concrete. Production quality control and cost control

[0004] At present, the existing polycarboxylate water-reducing agent already has a high water-reducing rate, and it can also make concrete achieve better workability and containment in conventional material systems such as cement, fly ash, mineral powder, and silica fume. Plasticity, but in the cement and limestone powder system, it is difficult to achieve good workability and plasticity. Moreover, according to the existing literature and reports, there is no special water reducer for limestone powder concrete.

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