The function of the water reducing agent is to improve the working performance of freshly mixed mortar and the fluidity of the mortar without reducing the water consumption of the cement; while maintaining a certain working performance, reduce the amount of cement and increase the strength of the mortar, under the circumstances, reduce the amount of cement per unit volume of mortar to save cement; improve the pumpability of the mortar mix and other physical and mechanical properties of the mortar. When the water-reducing agent is added to the mortar, the water-cement ratio can be significantly reduced, and the mortar’s good fluidity can be maintained. Generally speaking, the water reduction rate of high-efficiency water reducing agent can reach about 20%, while the water reduction rate of ordinary water reducing agents is about 10%. At present, it is generally believed that the water reducing effect of the water reducing agent is mainly due to the adsorption and dispersion of the water reducing agent.
Studying the hardening process of the cement in the mortar, it can be found that during the process of adding water to the cement, the cement minerals contain components with different charges, and the mutual attraction of positive and negative charges will cause the flocculent structure of the concrete. The flocculation structure may also be caused by the thermal movement of the cement particles in the solution, causing them to collide with each other at certain edges and corners and attract each other.
Because a lot of mixing water is wrapped in the flocculation structure, it cannot provide more water for cement hydration, so the workability of the new version of the concrete is reduced. Therefore, in order to make the cement hydrate better, it is necessary to increase the water consumption accordingly during mixing, but the increase in water consumption will cause excessive pores to form in the cement stone structure, causing its physical and mechanical properties to decline.