高精砌块专用抹面聚合物水泥砂浆配合比设计

High-precision Block Special Plaster Polymer Cement Mortar Mix Ratio Design

高精度蒸压加气混凝土砌块(高精砌块)与专用抹面砂浆的结合在一定程度上可以减少抹灰面厚度,有助于高效实现建材行业碳达峰、碳中和目标。为了探究最优砂浆配合比,从材料组成设计出发,利用粉煤灰、生石灰、重钙等低碳低成本材料和VAE替代部分水泥配制高精砌块专用抹面聚合物水泥砂浆。根据不同材料与不同掺量设计五因素四水平的正交试验,并对保水性试验、收缩性试验、抗冻性试验结果进行分析,确定水胶比为0.45、粉煤灰掺量为20%、生石灰掺量为3%、重钙掺量为9%、VAE掺量为3%。最终确定了专用抹面砂浆的最优配合比,即水、水泥、粉煤灰、生石灰、重钙、VAE、砂、空心漂珠、羟丙基甲基纤维素、淀粉醚的质量比为450∶620∶200∶30∶90∶30∶1800∶200∶4∶1;根据此配合比配制的聚合物水泥砂浆,当砂浆厚度仅为4 mm时,通过14 d拉伸粘结强度试验测得的砂浆强度便可满足现行规范的要求。

The combination of high-precision autoclaved aerated concrete block(high-precision block)and special plastering mortar can reduce the thickness of plastering surface to a certain extent,and help to effectively achieve the goal of carbon peak and carbon neutralization in the building materials industry.In order to explore the optimal mortar mix ratio,this paper starts from the material composition design,and uses low-carbon and low-cost materials such as fly ash,quicklime,heavy calcium and redispersible rubber powder were used instead of some cement to prepare high-precision block special plaster cement mortar.According to the orthogonal experiments of five factors and four levels of different materials and dosages,and the results of water retention test,shrinkage test and frost resistance test were analyzed.It was determined that the water-adhesive ratio was 0.45,the fly ash content was 30%,the quicklime content was 3%,the heavy calcium content was 9%,and the redispersible rubber powder content was 3%.The optimal mix of the final special plastering mortar is:water,cement,fly ash,quicklime,heavy calcium,redispersible rubber powder,sand,hydroxypropyl methylcellulose,Starch ether mass ratio of 450∶620∶200∶30∶30∶90∶30∶1800∶4∶1.According to this ratio of the polymer cement mortar,when the mortar thickness is only 4 mm,the mortar 14d tensile bonding strength measured by the tensile bonding test exceeds the current specification.