2. The influence of water reducer dosage and water consumption:

In practical applications, there is a problem of the optimal dosage of any water reducing agent. The preferred dosage depends on the type of cement, the amount of cement and the quality of the admixture. Before engineering application, it is necessary to find out the optimum dosage and optimum water consumption (water-binder ratio) of polycarboxylic superplasticizer water-reducing agent through repeated trial mixing according to the conditions of cement and admixtures. In engineering application, pay close attention to the glue Change the concrete material, and adjust the dosage slightly according to the change, so that the fresh concrete can reach the required state.

3. The influence of aggregate:

The mud content index of sand has a great influence on the performance of water reducing agent, especially the mud content of sand. When the mud content is greater than 3%, the performance of the water reducing agent is significantly reduced. It is difficult to obtain satisfactory fluidity by appropriately increasing the content. In the C30 cast-in-place pile concrete of a project in Jinan, when the content of polycarboxylic superplasticizer water-reducing agent (nofas) is 1.0%, it can meet the fluidity and expansibility required by the project. However, in practical applications, due to the high mud content of sand and gravel (mainly sand), the fluidity of concrete tends to decrease when mixing. Generally speaking, this problem can be solved by appropriately increasing the content of water reducing agent. But when the content of water reducing agent increases to a certain value, it still cannot meet the requirements. Some construction practices show that when the mud content is greater than 3%, the impact on the water-reducing agent is obvious, but when the mud content is greater than 5%, simply increasing the content of the water-reducing agent cannot solve the problem.