Polycarboxylate superplasticizer has the disadvantage of air entrainment, how to avoid it?

Key words
Polycarboxylate superplasticizer, defoamer, air entraining agent, polyether modified silane, sodium rosin

Polycarboxylate superplasticizers usually save some surface active ingredients that reduce surface tension during the production process, so it has certain air-entraining properties.

Polycarboxylate superplasticizer is a kind of surface active agent, and the air entrainment amount is large, which leads to a large amount of pores in the hardened cement stone, and a large number of air bubbles are introduced in the process of concrete mixing.

The concrete compounded with polycarboxylate superplasticizer is relatively viscous, and these air bubbles are difficult to be discharged by vibrating, which makes the concrete prone to apparent defects such as honeycomb hemp surface. Durability.

Polyether-modified silane defoamer can be well compounded with polycarboxylate superplasticizer, which can effectively reduce the amount of bubbles introduced. Although the bubbles were eliminated obviously, the expansion degree of the mortar decreased significantly.

Sodium rosin air-entraining agent can effectively restore the working performance of mortar and improve the expansion of mortar, thereby improving the compressive strength and durability of concrete.

The defoamer, the air-entraining agent and the polycarboxylate water reducer are compounded by the "first elimination and then adding" process of adding a defoamer and then an air-entraining agent, which can effectively solve the problem of the polycarboxylate superplasticizer. The bleed air disadvantage comes from the utility.