The role of polycarboxylate superplasticizer in mortar and concrete
The water reducing agent can mainly improve the strength of the mortar. It is an admixture with water reducing and reinforcing effects without affecting the construction workability of the mortar and concrete. Polycarboxylate water reducing agent is a new type of high performance water reducing agent developed in recent years, which has excellent water reducing rate, fluidity and permeability. The strength of the cement mortar is obviously enhanced, but the production process is complicated and the price is slightly higher than other water reducing agents. The water reducing agent has many functions, and is divided into an air-inducing type water reducing agent (a water reducing agent which also acts as a bleed air), an early-strong water reducing agent (a water reducing agent which acts as an early strong action), and a retarding type water reducing agent. (water reducing agent which also acts as a retarding agent).
The principle of action of the water reducing agent: the water reducing agent is usually a surfactant and is an anionic surfactant. It adsorbs on the surface of the cement particles to make the particles exhibit electrical properties. The particles repel each other due to the same charge, so that the cement particles are dispersed to release excess water between the particles to produce water reduction. On the other hand, due to the addition of the water reducing agent, the surface of the cement particles forms a suction film, which affects the hydration speed of the cement, makes the growth of the cement stone crystal more perfect, reduces the capillary gap of water evaporation, and the network structure is more compact and improved. The hardness and structural compactness of cement mortar.