羧基丁苯胶乳在水泥砂浆中引泡规律及消泡特性研究

Research on Foaming Rules and De-foaming Characteristics of Carboxylated Styrene Butadiene Latex in Cement Mortar

研究了羧基丁苯胶乳在水泥砂浆内部引入气泡特征,分析了消泡剂对气泡的影响规律。结果表明:随着羧基丁苯胶乳掺量的增加,其含气量不断增加,掺量为25%时可达普通水泥砂浆的4.86倍;硬化后气孔含量增加,且以≥1000μm的气孔含量居多;不同种类消泡剂均降低了含气量,D类消泡效果最好,掺量为0.6%时含气量比未加消泡剂试验结果降低了53.3%,但高出标准试验结果60.0%;增加D类消泡剂的掺量,未能彻底消除气泡,过量消泡剂减小了5~200μm尺寸内的气孔含量,但大尺寸气泡有增加的趋势。

The air bubble characteristics of carboxylated styrene butadiene latex in cement mortar are studied,and the influence of de-foaming agent on bubble is analyzed.The results indicate that:(1)with the increase of the content of carboxylated styrene butadiene latex,the gas content increases continuously, and when the dosage is 25%,it can reach 4.86 times of ordinary cement mortar;the porosity of hardened cement mortar increases,and the stomatal content of more than 1000μm is the majority.(2) Different defoaming agents can reduce the gas content,type D de-foaming effect is best,when the content is 0.6%, the gas content is 53.3% lower than that without de-foaming agent,but the result is 60%higher than the standard test result.And (3) increase the amount of D defoamer cannot completely remove the air bubble, the excess defoaming agent reduces the pore content in the size of 5μm^200μm,but larger bubbles have a tendency to increase.