憎水剂影响硅酸盐水泥基饰面砂浆泛白的机理

Effect of Hydrophobic Agent on Efflorescence of Portland Cement-Based Decorative Mortar

研究了憎水剂对硅酸盐水泥基饰面砂浆1~180d泛白的影响,并对其1d的作用机理进行了探讨.结果表明:憎水剂可明显抑制硅酸盐水泥基饰面砂浆28d内的早期泛白,对其28~180d较长龄期的泛白则影响较小;1d时,憎水剂增大了硅酸盐水泥基饰面砂浆内部50nm^1μm的大毛细孔比例,明显降低了其孔溶液中K+,Na+的浓度,并抑制它们的迁移,使表面溶出的碱性离子总含量明显降低,从而降低了表面的盐浸出率,起到了抑制泛白的作用.

The effect of hydrophobic agent on the efflorescence of Portland cement-based decorative mortar （PCDM） cured for 1-180 d and the mechanism of the effect for PCDM cured for 1 d were investigated.The results show that the early efflorescence of PCDM cured for less than 28 d is significantly reduced by adding hydrophobic agent,but the efflorescence of PCDM cured for 28-180 d is only little affected.For PCDM cured for 1 d,the addition of hydrophobic agent increases its larger capillaries with 50 nm-1 μm.However,the addition of hydrophobic agent decreases the concentrations of K＋,Na＋ ions in the pore solution,and prohibits their mobility,so that the total leachability of alkalis ions on the surface of PCDM is decreased,and the leachabilty of surface salts and efflorescence of PCDM is reduced.