The precautions of polycarboxylic acid water reducing agent mainly include the following six points:
1. There is a problem with the adaptability of cement. For some cements, the water reduction rate is low and the slump is large. Therefore, when the cement adaptability is not good, the concrete trial mix should be adjusted to adjust the composition of the water reducing agent. best effect. In addition, the fineness and storage time of cement will also affect the use of polyacid water reducer.
2. It is more sensitive to changes in raw materials. When the quality of sand, stone materials and admixtures such as fly ash, slag powder and other raw materials changes greatly, it will affect the performance of concrete mixed with polycarboxylic acid water reducing agent , It should be re-tested with the changed raw materials to adjust the blending amount to achieve the best results.
3. Due to the high water reduction rate, the slump of the concrete is particularly sensitive to water consumption. Therefore, it is necessary to strictly control the amount of polycarboxylic acid water reducing agent and the water consumption of concrete during the use. Once the amount is excessive, the concrete will appear segregation, bleeding, compaction and excessive gas content and other adverse phenomena.
4. It is particularly sensitive to the mud content of the aggregate. Excessive mud content reduces the performance of the polycarboxylic acid water reducer. Therefore, the quality of aggregate should be strictly controlled when using polycarboxylic acid water reducing agent. When the mud content of the aggregate is increased, the amount of polycarboxylic acid water reducing agent should be increased.
5. Polycarboxylic acid water reducer cannot be mixed with naphthalene series water reducer. When using polycarboxylic acid water reducer, the mixer and mixer truck that have been used with naphthalene series water reducer must be cleaned, otherwise polycarboxylic acid may The water reducing agent loses its water reducing effect.
6. Avoid long-term contact with iron materials. Because polycarboxylic acid water reducer products often show acidity, long-term contact with iron products will cause slow reactions, and even make them darker and darker, resulting in decreased product performance. It is recommended to use polyethylene plastic bucket or stainless steel bucket for storage to ensure its performance stability.