Please compare air-entraining agents and Pozzolith [a trading name of one particular water-reducing admixture]. Air-entraining agents incorporate air into the concrete mix to improve resistance to freezing and thawing or salt scaling. Still, often they are added to improve workability. Since air provides no strength, a small amount of additional cement is often required to compensate for the strength that might otherwise be lost. However, the incorporation of air makes it possible to reduce the water-cement ratio needed to produce a given slump.
For this reason, not as much extra cement is needed as would be if the water-cement ratio remained the same. Air-entraining agents should conform to ASTM C 233. Water-reducing admixtures have a more pronounced effect on the water needed for a given slump. They are supplied in three common forms: normal, retarding, and accelerating. Normal water-reducing admixtures are added for any or all of many reasons. The most common is to permit the use of less cement by reducing the water-cement ratio and improving workability. Water-reducing admixtures frequently entrain some air and may help control the air content within limits. Retarding water-reducing admixtures perform the same functions as those just described, but they also delay the set rate and, therefore, find use in hot weather or when longer working times are needed. Accelerating water-reducing admixtures also performs the same functions as normal admixtures but accelerates the set rate and hardening. They are useful in cold weather or where high early strength is needed. Water-reducing admixtures should conform to ASTM C 494. If you are looking for high quality, high purity, and cost-effective water-reducing agent, or if you require the latest price of a water-reducing agent, please feel free to email contact mis-asia.
