利用BBD实验计研究化学添加剂协同作用对水泥砂浆强度的影响.docxVIP

利用BBD实验设计研究化学添加剂协同作用对水泥砂浆强度的影响 摘 要 利用 Box-Behnken 实验设计( BBD) 方法研究水溶性聚合物（聚乙烯醇(PVA)、聚丙烯酰胺(PAM)）和化学添加剂（有机硅消泡剂(SD)、聚羧酸减水剂(PC)）复配对水泥砂浆抗压强度的影响。得出能反映化学组分掺量与水泥砂浆强度关系的二次方程，化学组分与水泥砂浆强度的帕累托图（Parrot）。结果表明：SD和PAM的交互作用对水泥砂浆1d，3d和28d的强度贡献分别是16.5%，20.1%和19.4%。通过重叠等值线图得出了提升强度的最优区间，进一步通过水化热分析和扫描电镜图（SEM）探讨了SD和PAM的交互作用对水泥砂浆强度的提升的影响，主要是因为水泥水化过程中有机硅消泡剂的物理行为和聚丙烯酰胺的化学反应协同作用的结果。 关键词：Box-Behnken 实验设计；水性聚合物；化学外加剂；砂浆强度 Synergistic Interactions of Chemical Additives on the Strength Development of Silicate Cement by a Box-Behnken Design SHAO Gaofeng （State Key Laboratory of Materials-Oriented Chemical Engineering, College of Materials Science and Engineering, Nanjing University of Technology, Nanjing, 210009, China） ABSTRACT：The effect of water-soluble polymers (polyvinyl alcohol (PVA), polyacrylamide (PAM)) and chemical additives (silicone defoamer (SD), polycarboxylate superplasticizer (PC)), on the development of the strength of mortar was investigated using the Box-Behnken design (BBD). Quadratic equations were obtained for the correlation between dosages of chemicals and the strength of the mortar, and the order of the effectiveness of the chemicals was validated in Pareto charts with contour plots to illustrate the chemicals and their interactions on the strength enhancement of mortar. The results showed that the interaction effects of SD and PAM enhanced the strength of cement mortar for all curing times, and the rates of contribution were 16.5%, 20.1%, and 19.4%, respectively. Based on the performance analysis of the four additives, optimized formulations were highlighted via overlapped contour plots. Heat of hydration and scanning electron microscope (SEM) images were introduced to confirm the interaction between SD and PAM. The improvement of compressive strength attributes to the synergistic interactions between SD and PAM, including the physical interaction resulted from the doping of SD, which promoting the damage of air bubble, decreasing the porosity and increasing the compre