The mechanical properties of polymer modified cement mortar ware studied based on the orthogonal experiment.Four factors as water-binder ratio(A),polymer-binder ratio(B),sand-binder ratio(C) and active mineral mixture replacement rate(D) ware investigated,and each factor had four level values.The experimental results ware conducted and studied according to the orthogonal table L16(45).It shows that the significant effect degree of the four factors on the different mechanical performance indexes was not the same,and the significant effect degree concluded from the variance analysis of repeated test data was larger,compared with the separate tests.The variance analysis of repeated test shows that factor C and D had a significant effect on the flexural strength of polymer modified cement mortar,while B and D were key factors of the bending strength.

通过系统试验,研究了不同养护制度对聚合物改性水泥砂浆强度的影响.研究结果表明,随着龄期的增长,养护制度对聚合物改性水泥砂浆强度有显著影响.在各养护制度下,各龄期的普通水泥砂浆强度均高于聚合物改性水泥砂浆的相应强度值;混合养护制度更利于聚合物改性水泥砂浆强度的增长;前21d采用混合养护、之后采用标准养护对改善聚合物改性水泥砂浆的脆性有利.

地下立体车库具有广阔的应用前景,其挡土侧墙受力复杂且结构重要.结合菜单层地下敞口式立体车库实际工程进行设计分析.重点考察了不同侧墙厚度、不同混凝土强度等级及不同边界约束条件下的8种工况.基于一定的假定简化,采用弹性薄板小挠度理论,采用单重、正弦三角级数展开式的数值解求解方法对挡土侧墙进行分析.通过计算结果的对比分析得到合理的设计方案.这一思路对类似工程的结构设计具有一定的借鉴意义.

An experimental study on the relativity between polymer cement ratio, silence coupling agent, defoamer, shrinkage reducing admixture and the setting time of polymer modified cement mortar was carried out. The results show that the influence of polymer cement ratio, coupling agent, defoamer and shrinkage reducing admixture content on the setting time is significant. Compared with ordinary cement mortar, the setting time of polymer cement mortar was extended, and increased with the polymer cement ratio increase, but the increase rate was more and more slow. The setting time increased with the contents of the three kinds of admixtures increase, but the increase rate decreased with the polymer cement ratio increase. The influence of polymer cement ratio was more than admixtures. Anhydrous alcohol used as the diluting agent for coupling agent intensified the setting time extension of polymer modified cement mortar. Considering the setting time, the optimal amount of polymer and admixtures as follow: the polymer cement ratio was 0?1 , defoamer content was 3‰, coupling agent content was 3‰, shrinkage reducing admixture content should not be greater than 2%. The mechanism of action of these three kinds of admixtures was discussed.

According to the fact that the extensive application of the defoamer in the polymer modified cement mortar and the rare study on its influence of the setting time of the mortar, the study researches the influence of the mixing volume of defoamer on the setting time, and finds the increasing mixing defoamer can postpone the setting time of the polymer modified cement mortar.

针对国内不同研究机构和学者对砂浆黏结性能测试时,采用的试验方法存在较大的差异,而且劳动强度大、工作效率低、试验周期长等缺点,设计制作了一套水泥砂浆黏结拉拔试验夹具及成型模具并在试验研究中进行了应用.试验结果表明:采用该试验夹具进行砂浆与基体材料的黏结拉拔试验是可行的,不仅可以用于施工工地既有基体材料黏结强度的测试,而且可以避免应力集中和试验数据离散.