轻质聚合物干粉抹面砂浆抗压强度与抗冻性

外墙抹面砂浆作为建筑物外表层常年受到冻害侵扰，为有效缓解冻害破坏及厘清劣化机理。以空心漂珠作细集料，掺入聚合物干粉与重钙制备不同水灰比的轻质抹面砂浆，通过正交试验，揭示水灰比、可再分散乳胶粉掺量及重钙掺量对抗压强度和抗冻性能的影响规律，并探讨砂浆性能变化的微观机理。结果表明：水灰比对抗压强度影响显著，可再分散乳胶粉掺量次之，重钙掺量影响最小。对于抗冻性能可再分散乳胶粉掺量影响显著，重钙掺量影响最小；在不同养护龄期下，水灰比对抗压强度影响较大，可再分散乳胶粉掺量对抗冻性能影响较大。若将水灰比控制在0.35附近，可再分散乳胶粉掺量与重钙掺量保持在3%以内，虽然抗压强度小幅降低，但抗冻性能优异。综合考虑抗压强度和抗冻性能的实际需求，外墙抹面砂浆的抗冻性能重要程度远大于抗压强度，基于此，可确定干粉抹灰的最优配比为水灰比0.37、可再分散乳胶粉掺量2.8%、重钙掺量3.9%。此外，也可结合实际工作环境与工程要求，设计不同配比的干粉抹灰。

Lightweight polymer dry powder mortar compressive strength and frost resistance

As the outer surface layer of the building, the exterior wall plastering mortar is subject to frost damage all year round, in order to As the outer surface layer of a building, the exterior wall plastering mortar is affected by frost damage all year round, in order to effectively alleviate frost damage and clarify the deterioration mechanism. In this study, fine aggregate, such as hollow floating bead, was utilized. Heavy calcium and polymer dry powder were mixed with cement to prepare light plaster with different water-cement ratios. Through orthogonal test, the effects of water-cement ratio, content of redispersible polymer powder, and heavy calcium content on compressive strength and frost resistance were revealed. And the microscopic mechanism of mortar performance change was discussed. The results show that the water-cement ratio has a significant effect on compressive strength, followed by the amount of redispersible polymer powder. And the effect of heavy calcium content is the least significant. Regarding antifreeze performance, the quantity of redispersible polymer powder has a significant impact, and the quantity of heavy calcium has the least impact. At different curing stages, the water-cement ratio has a greater influence on compressive strength, and the amount of redispersible polymer powder has a greater effect on the anti-freezing performance. If the water-cement ratio is maintained around 0.35, the contents of redispersible polymer powder and heavy calcium are limited to 3%. Although the compressive strength is slightly reduced, the frost resistance is excellent. Considering the actual needs of compressive strength and frost resistance, the frost resistance of exterior wall plastering mortar is of greater importance than compressive strength. Based on this, it can be concluded that the optimal ratio for dry powder plastering is 0.37 water-cement ratio, 2.8% redispersible polymer powder content, and 3.9% heavy calcium content. Additionally, in combination with the actual working environment and engineering requirements, dry powder plasters with different proportions can be designed.