Precautions for Polycarboxylic Acid Superplasticizer
1.Polycarboxylic Acid Superplasticizer has problems with the adaptability of cement. For individual cements, the water reduction rate is low and the slump is large. Therefore, when the adaptability of the cement is not good, the concrete should be tested and adjusted to reduce the water. Agent components to achieve the effect. In addition, the fineness and storage time of cement will also affect the use effect of polycarboxylic acid water-reducing agent.
2. It is more sensitive to the changes of raw materials. When the quality of sand, stone materials and admixtures such as fly ash, mineral powder and other raw materials changes greatly, it will have a certain impact on the performance of concrete mixed with polycarboxylic acid water-reducing agent. , It is necessary to re-test the changed raw materials to adjust the dosage to achieve the effect.
3. Due to the high water reduction rate, the concrete slump is particularly sensitive to water consumption. Therefore, the mixing amount of polycarboxylic acid water-reducing agent and the water consumption of concrete must be strictly controlled during use. Once the amount is exceeded, the concrete will have undesirable phenomena such as segregation, bleeding, compaction and excessive air content.
4. It is particularly sensitive to the mud content of aggregates. Excessive mud content will reduce the performance of polycarboxylic acid water-reducing agent. Therefore, the quality of aggregate should be strictly controlled when using polycarboxylic acid water reducing agent. When the aggregate mud content increases, the mixing amount of polycarboxylic acid water reducing agent should be increased.
5. Polycarboxylic acid water-reducing agent cannot be mixed with naphthalene-based water-reducing agent. When using polycarboxylic acid water-reducing agent, the mixer and mixer truck that have used naphthalene-based water-reducing agent must be rinsed, otherwise it may cause polycarboxylic acid The water reducing agent loses its water reducing effect.
6. Long-term contact with iron materials should be avoided. Since polycarboxylate water-reducing agent products are often acidic, they will react slowly after long-term contact with iron products, and even darken and blacken the color of the product, resulting in a decline in product performance. It is recommended to store in polyethylene plastic bucket or stainless steel bucket to ensure its performance stability.
