The water reducing agent is added to the concrete mixture to disperse the cement particles, which can improve the workability, reduce the unit water consumption, improve the fluidity of the concrete mixture, or reduce the amount of cement used to save cement.
The effect of the change in temperature difference on the slump of the concrete, we will also adjust accordingly when using the water reducing agent, in order to achieve the expected state of concrete.
1. The polycarboxylate water-reducing agent still has the problem of adaptability to cement. For some cements, the phenomenon of low water reduction rate and large damage will occur. Therefore, when the adaptability of cement is not good, the concrete trial adjustment should be carried out. The amount of agent is added to achieve the best results.
In addition, the fineness and storage time of the cement also affect the use of the polycarboxylate superplasticizer.The use of hot cement should be eliminated in production.If the hot cement is mixed with the polycarboxylate superplasticizer, it shows that the initial slump of the concrete is more likely to come out.However, the protective effect of the admixture is weakened, and there is a possibility of rapid loss of concrete slump.
2. Polycarboxylate superplasticizer is sensitive to changes in raw materials,When the quality of raw materials such as sand, stone materials and admixtures such as fly ash and mineral powder changes greatly, it will have certain influence on the concrete performance of the polycarboxylate superplasticizer.The test should be re-tested with the changed raw materials to adjust the dosage to achieve the best results.
3. Polycarboxylate superplasticizer is particularly sensitive to the mud content of aggregates,The excess mud content reduces the performance of the polycarboxylate superplasticizer.Therefore, the quality of the aggregate should be strictly controlled when using the polycarboxylic acid water reducing agent.When the aggregate content of the aggregate is increased, the amount of the polycarboxylic acid water reducing agent to be used should be increased.
4. Polycarboxylate superplasticizer is particularly sensitive to water consumption due to its high water reduction rate.Therefore, the water consumption of concrete must be strictly controlled during use.Once over-extended, concrete will have undesirable phenomena such as segregation, bleeding, compaction and excessive gas content.
5. The polycarboxylate water reducing agent should be used to increase the stirring time in the production process of the concrete (generally twice as high as the traditional admixture), so that the steric hindrance of the polycarboxylate superplasticizer can be more easily played.It is convenient to control the concrete slump in production.The mixing time is not enough, it is likely that the slump of the concrete delivered to the site is larger than the concrete slump controlled by the mixing station.