What is the polycarboxylate uses?
The molecule of polycarboxylic acid (salt) water reducer is a “comb” or “dendritic” structure artificially formed by “molecular design”, and there are many branch chains (side chains) with a certain length and stiffness on the molecular main chain. There are also sulfonates or other groups on the main chain that can make the cement particles charged, which can play the role of traditional water reducing agents, and more importantly, once the main chain is adsorbed on the surface of the cement particles, the branch chain forms a three-dimensional cross with the branch chain on the surface of other particles, preventing the particles from approaching each other, so as to achieve dispersion (that is, water reduction). This steric hindrance does not weaken with the extension of time, so the dispersion of polycarboxylic acid superplasticizer is more lasting.
What is the polycarboxylate？
Polycarboxylic acid superplasticizer is a commonly used concrete additive, which can effectively reduce the amount of cement in concrete, improve the flow of concrete and reduce the shrinkage rate of concrete. However, the use of polycarboxylic acid superplasticizer also needs to pay attention to some problems, the following to introduce in detail how polycarboxylic acid superplasticizer should be used.
First of all, the use of polycarboxylic acid superplasticizers should follow the following principles:
- Select the appropriate variety of polycarboxylic acid superplasticizer, and select the suitable variety of polycarboxylic acid superplasticizer according to the nature and requirements of concrete.
- Use polycarboxylic acid superplasticizer in strict accordance with the instructions for use, not excessive use or improper use.
- In the design of concrete mix ratio, the use of polycarboxylic acid superplasticizer should be considered, and the water-cement ratio and the dosage of polycarboxylic acid superplasticizer should be reasonably controlled.
Secondly, the use of polycarboxylic acid superplasticizer is as follows:
- Before mixing the concrete, add the polycarboxylic acid superplasticizer to the water of the concrete and stir it fully.
- In the process of concrete mixing, polycarboxylic acid superplasticizer should be added as needed to ensure the fluidity and working performance of concrete.
- In the construction process of concrete, attention should be paid to the slump and fluidity of concrete, and the dosage of polycarboxylic acid superplasticizer should be adjusted in time.
Finally, the precautions for polycarboxylic acid superplasticizers are as follows:
- The amount of polycarboxylic acid superplasticizer should be reasonably controlled according to the nature and requirements of concrete, and should not be used in excess.
- The use of polycarboxylic acid water reducer shall follow the instructions for use, and shall not be used improperly or beyond the use period.
- The storage of polycarboxylic acid water reducer should pay attention to moisture, sun protection, anti-freezing, and avoid mixing with other chemicals.
In short, polycarboxylic acid superplasticizer is an important concrete additive, which can effectively improve the performance and working performance of concrete. However, when using polycarboxylic acid superplasticizers, we also need to pay attention to some problems to ensure the quality of concrete and the safety of the project.