Should a defoamer be used first when compounding the polycarboxylate water-reducing agent? Use air entraining agent first. Will there be any impact?

Yes! Use defoamer first. Because the domestic polycarboxylic acid mother liquor synthesis technology is not very mature, the foaming is very high, uneven, and easy to break. Defoaming agent is used first to eliminate uneven and easily broken bubbles (harmful bubbles, which will affect the strength of concrete, such as bubbles larger than 3MM), and finally compound air-entraining agent to obtain small, uniform and stable bubbles. Air-entraining agents are surfactants with strong interfacial energy, which can prevent bubbles from breaking easily. If the air-entraining agent is added first, there will be many unevenly sized bubbles that are not suitable for crushing. However, large bubbles will affect the strength of the concrete.