引气剂对水泥基饰面砂浆泛白的影响及其机理

Effect of Air Entraining Agent on Efflorescence of Cement-Based Decorative Mortar and Its Mechanism

研究了引气剂对硅酸盐水泥基饰面砂浆初次泛白和二次泛白的影响及其作用机理.结果表明:引气剂通过引气和促凝作用能显著抑制硅酸盐水泥基饰面砂浆的初次泛白,还能显著减轻硅酸盐水泥基饰面砂浆7d前的二次泛白,消除7d后的二次泛白.原因在于引气剂虽会导致硅酸盐水泥基饰面砂浆总孔隙率增多,但能显著减少小毛细孔的比例,同时可显著降低孔溶液中K+,Na+的质量浓度,并抑制它们的迁移,使表面溶出的碱性离子总含量显著降低,从而降低表面浸取液中的固体含量,起到抑制二次泛白的作用.

Effects of air entraining agent on the primary efflorescence and secondary efflorescence of Port- land cement-based decorative mortar（PCDM）and its mechanism were studied. The results show that air entraining agent significantly prohibits the primary efflorescence of PCDM by its outstanding air entraining effect and procoagulant effect. Air entraining agent also significantly reduces the secondary efflorescence of PCDM with ages shorter than 7 d, and eliminates the secondary efflorescence of PCDM with ages longer than 7 d, so that it decreases the proportion of small capillaries, and the concentrations of K＋ , Na＋ in the pore solution, and also prohibits these ions＇ mobility, accordingly greatly decreases the total leachability of alkali ions on the surface of PCDM. So the solid content in the surface leaching solution and secondary efflorescence degree of PCDM are reduced.