可再分散乳胶粉改性水泥基薄喷材料研究

Modification of Cement-Based Thin Spray Material by Redispersible Emulsion Powder

聚合物改性水泥基韧性薄喷材料是煤矿巷道表面封闭材料的发展方向,可再分散乳胶粉具有增加水泥基材料黏结性、改善韧性的特点,但目前关于可再分散乳胶粉改性水泥基薄喷材料的研究较少。本文采用可再分散乳胶粉改性硅酸盐与硫铝酸盐复合水泥制备薄喷材料,研究了可再分散乳胶粉对浆液黏度、凝结时间以及结石体抗折和抗压强度、单轴压缩应力-应变、单轴拉伸荷载-位移的影响。结果表明,随可再分散乳胶粉掺量增加,浆液黏度快速增加的起始时间延长,凝结时间增加,结石体抗折、抗压强度均先升高后降低,在掺量为2.25%(质量分数)时达到最大值,压缩、拉伸破坏变形率均增加,韧性得到改善。通过微观分析阐释了可再分散乳胶粉对水泥基材料宏观性能的影响机理。

Polymer modified cement-based toughness thin spray material is the development direction of coal mine roadway surface sealing material. Redispersible emulsion powder has the characteristics of increasing cement-based material adhesion and improving toughness, but at present, there is less research on redispersible emulsion powder modified cement-based thin spray material. In this paper, thin spray material was prepared by using silicate and sulphate aluminium composite cement modified by redispersible emulsion powder, and the effect of redispersible emulsion powder on slurry viscosity, setting time, and flexural and compressive strength, uniaxial compressive stress-strain and uniaxial tensile load-displacement of the stone body was studied. The results show that with the increase of the content of redispersible emulsion powder, onset time for rapid increase of slurry viscosity is extended, setting time increases, the flexural and compressive strength of the stone body increase first and then decrease, and reach the maximum value at the content of 2.25%(mass fraction), and the compression and tensile deformation rates increase and the toughness is improved. The mechanism of the effect of redispersible emulsion powder on the macroscopic properties of cement-based materials was explained by microscopic analysis.