聚羧酸减水剂引气效应复配优化研究

Optimization of Air Entrained Effect of Polycarboxylate Superplasticizer

关键词:  聚羧酸减水剂  引气效应  气孔结构  协同配伍

Key words:  polycarboxylate superplasticizer  air entrained effect  pore structure  synergistic compatibility

摘要:

针对聚羧酸减水剂普遍存在的引气量过大，泡径不良等问题，采用“消大泡，引小泡”的工艺方法，将聚羧酸减水剂与不同种类的消泡剂和引气剂进行复配，以砂浆含气量、流动性、抗压强度和孔结构参数为指标，研究减水剂、消泡剂和引气剂三者间的协同配伍关系.结果表明：消泡剂能够显著降低聚羧酸减水剂引入劣质气泡的含量，提高砂浆强度，但会降低砂浆的流动性；引气剂能够增加10～300μm直径范围内的气泡含量，降低消泡剂对砂浆流动性的负面影响，提高砂浆工作性能.因此，通过“消大泡，引小泡”的工艺方法能够在保持砂浆流动性的同时，提高其抗压强度.

Abstract:

In order to solve the excessive air and poor bubble size distribution introduced by polycarboxylate superplasticizer, the process of “eliminating large bubbles and introducing small bubbles” was adopted. Polycarboxylate superplasticizer was compounded with different kinds of defoaming agents and air entraining agents. The synergistic compatibility between polycarboxylate superplasticizer, defoaming agents and air entraining agents was studied by taking air content, fluidity, compressive strength and pore structure parameters of the mortar as indicators. The results show that the defoaming agent can significantly reduce the content of inferior bubbles introduced by polycarboxylate superplasticizer, and improve the strength, as well as reduce the fluidity of mortar. The air entraining agent can increase the bubble content in the diameter range of 10300μm, and reduce the negative influence of the defoaming agent on the fluidity to improve the working performance of the mortar. Therefore, the process of “eliminating large bubbles and introducing small bubbles” can improve the compressive strength while maintaining the fluidity of mortar.