Water-reducing agent means that it can reduce the amount of mixing water when the slump of concrete is the same; or it can reduce the amount of mixing water when the concrete mix ratio and water consumption remain unchanged. Admixtures that increase the slump of concrete. According to the water reduction rate or slump increase, it is divided into two categories: ordinary water reducing agent and high-efficiency water reducing agent.
In addition, there are compound water-reducing agents, such as air-entraining water-reducing agents, which have both water-reducing and air-entraining effects; early-strength water-reducing agents The water-reducing agent not only has the function of reducing water, but also improves the early strength; the retarding water-reducing agent also has the function of delaying the setting time, etc.
(1) The main functions of water reducing agent.
1. Significantly improve liquidity when the mix ratio remains unchanged.
2. When the fluidity and cement dosage remain unchanged, reduce water consumption, lower the water-cement ratio, and improve strength.
3. While maintaining fluidity and strength, save cement usage and reduce costs.
4. Improve the workability of concrete
5. Improve the durability of concrete
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6. Configure high-strength and high-performance concrete.
Polysulfonate series: including naphthalene sulfonate formaldehyde condensate (NSF), melamine sulfonate formaldehyde condensate (MSF), p-aminobenzene sulfonate Acid formaldehyde condensation polymer, modified lignin sulfonate, polystyrene sulfonate and sulfonated ketone-aldehyde resin, etc. For example, our commonly used FDN is a naphthalene sulfonate formaldehyde condensate.
Polycarboxylate series: effectively control the initial hydration process and reduce the slump loss of concrete.
The difference between high-efficiency water-reducing agent and ordinary water-reducing agent is mainly reflected in that the high-efficiency water-reducing agent can continuously increase the fluidity within a large range. Or the water demand continues to decrease. The effective range of ordinary water reducing agents is small.
The effect of the water-reducing agent at a small dosage cannot be used as the basis for judging the performance of the water-reducing agent. This should be noted when selecting water reducing agents. The optimal amount of water-reducing admixture should be determined through experiments, and should not be used solely based on the amount of water-reducing admixture manufacturer. </p