Polycarboxylate Superplasticizer is considered to be a high-performance admixture. People always expect to be safer, more convenient, more efficient, and more adaptable than traditional naphthalene admixtures in applications, but the actual situation is not the case. Is encountering different problems. So, what are the precautions for the use of polycarboxylic acid admixtures?
1. Polycarboxylate Superplasticizer needs to control the amount of water reasonably. On the one hand, in order to ensure the water-binder ratio, on the other hand, because polycarboxylate superplasticizer is very sensitive to water consumption. The indicators that usually reflect the performance of concrete mixtures include fluidity, cohesion and water retention. Because polycarboxylate superplasticizer is very sensitive to water consumption, sometimes the water consumption is only increased by 1kg~3kg during the trial and production process. Severe bleeding, piles of exposed rocks, grabbing the bottom from the mat, etc., cannot guarantee the uniformity of the concrete mixture. Therefore, the unilateral water consumption must be strictly controlled during production.
2. Control the content of polycarboxylic acid. Insufficient content of concrete is manifested by rapid slump loss, large loss, and poor fluidity; too much will cause severe bleeding, segregation, and bottom grabbing. It is necessary to conduct multiple tests to determine the best fit between water consumption and polycarboxylate superplasticizer content. Point, that is, the optimal water consumption and admixture dosage.
3. It is strictly forbidden to mix naphthalene admixtures. According to different projects, most concrete mixing plants need to use naphthalene admixtures while using pce. If conditions permit, it is best to use in separate stations. If the same unit contains both polycarboxylate superplasticizer and naphthalene, the weighing container, pipeline and mixer for the admixture must be thoroughly cleaned when alternate use, and the concrete tanker should also be cleaned. Clean and reload. If polycarboxylic acid and naphthalene-based admixtures are mixed and used, the two admixtures will react to make the concrete "rapidly set", causing the entire vehicle to be scrapped.
4.Strengthen the inspection of polycarboxylate superplasticizer admixtures. While checking the admixtures, take samples from the existing raw materials that will be used, and test the concrete according to the technical requirements of the project. If any problems are found, please promptly ask the technical personnel of the admixture manufacturer to make adjustments.
In short, concrete polycarboxylic acid admixture is a new type of material. Compared with traditional water reducers, it not only has a relatively small dosage, high water reduction rate, low chlorine and low alkalinity, and relatively obvious slump retention effect. Improve the durability of concrete structure, and the production process of polycarboxylate superplasticizer water reducer is clean and pollution-free. It is a new type of green and environmentally friendly high-performance water reducer.
Post time: Oct-27-2021