Concrete water reducer can be divided into high-efficiency water reducer, air-entraining water reducer, ordinary water reducer and so on. It can reduce the water consumption of concrete, greatly improve mixing efficiency, and also save cement. Let's understand its mechanism of use. Spatial steric hindrance: The hydrophilic polyether side chain of water reducer structure extends in aqueous solution, thus forming a hydrophilic three-dimensional adsorption layer of Baidu on the surface of the adsorbed cement particles. When the cement particles are close to each other, the adsorption layer begins to overlap, that is, there is a sudden steric hindrance between the cement particles. The more the overlap, the greater the steric hindrance, the greater the hindrance to the cohesion between the cement particles, and the better the slump of concrete. Slow-release effect of graft copolymerization branched chain: In the process of preparation of new water reducers such as polycarboxylic acid water reducer, some branched chains are grafted on the molecules of water reducer. The branched chain not only provides steric hindrance effect, but also can be cut off slowly in the high alkalinity environment of cement hydration, releasing some components from the surface. A number of polycarboxylic acids can improve the dispersion effect of cement furnace and control slump loss. |
