Abstract:

To improve the hydrophobicity of calcium aluminate cement products,calcium aluminate cement paste samples and corundum castable samples were prepared with calcium aluminate cement,polydimethylsiloxane,tetraethoxysilane,tabular corundum,etc.as starting materials.The entire hydrophobic modification was adopted,and the effects of the addition of hydrophobic modifier polydimethylsiloxane (0,1%,2% and 5% of the water addition,by mass) on the setting time of calcium aluminate cement paste and the hydrophobicity of the paste samples,as well as on the density,the cold strength and the hydrophobicity of corundum castable samples were studied.The results show that:with the increase of the polydimethylsiloxane addition,the initial setting time and the final setting time of the calcium aluminate cement paste are prolonged;the density of the castable samples decreases slowly,the cold compressive strength and the cold modulus of rupture decrease significantly;the water contact angle increases from 113° to 151°,gradually improving the hydrophobic performance,and the samples have high stability to acid,alkali and boiling water.

Key words: aluminate cement, hydrophobicity, setting time, compressive strength

摘要：

为了提高铝酸钙水泥制品的疏水性,以铝酸钙水泥、聚二甲基硅氧烷、正硅酸乙酯、板状刚玉等为原料,研究了采用整体疏水改性时,疏水修饰剂聚二甲基硅氧烷加入量(分别为加水质量的0、1%、2%和5%)对铝酸钙水泥净浆凝结时间、净浆试样疏水性的影响,以及对刚玉浇注料试样的致密度、常温强度、疏水性能的影响。结果表明:1)随着疏水修饰剂聚二甲基硅氧烷加入量的增多,铝酸钙水泥净浆的初凝时间和终凝时间均有所延长。2)随着疏水修饰剂聚二甲基硅氧烷加入量的增多,浇注料试样的致密度缓慢减小,常温耐压强度和常温抗折强度显著减小;水接触角由113°增大至151°,疏水性能逐渐提高,且对酸、碱、沸水具有极高的稳定性。

关键词: 铝酸盐水泥, 疏水性, 凝结时间, 强度