聚丙烯酰胺水泥土力学性能及耐久性能试验研究

发布时间：2018-08-04 07:54

【摘要】：水泥土材料是一种绿色经济的环保型建筑材料，在众多的工程当中被广泛应用，但是这种材料存在一定的缺陷与不足，仍需要继续进行深入研究。本文主要通过进行聚丙烯酰胺对水泥土强度及耐久性方面的试验研究，分析了聚丙烯酰胺对水泥土材料的增强机理和耐久性增强机理。本文首先设计聚丙烯酰胺单掺试验，测定不同聚丙烯酰胺掺量下水泥土试块各龄期的无侧限抗压强度，试验结果分析表明：随着聚丙烯酰胺掺量的增加，水泥土强度先增加后减小，证明在聚丙烯酰胺掺量低于10%时存在一个最优掺量；在聚丙烯酰胺掺量适量时，水泥土体中其分子浓度适中，，可以改善土颗粒表面特性，促使水泥土形成整体胶结加筋结构，从而起到增强水泥土强度的作用；但是，当聚丙烯酰胺掺量过多以后，水泥土体中其分子浓度过大，分子间无法形成有效地结合，土颗粒之间的结合力被大大削弱，部分土颗粒已经脱离了整体结构，使得水泥土的整体性明显减低，从而导致水泥土的强度降低。其次，对各试验组进行干湿循环试验和冻融循环试验。干湿循环试验结果表明随着聚丙烯酰胺掺量的增加水泥土试块表面侵蚀现象逐渐减轻，材料抵抗干湿循环的能力不断增强；冻融循环试验结果表明聚丙烯酰胺可以显著改善冻融循环环境下水泥土的力学性能和耐久性能。最后，本文对土体固化前后的微观结构特征进行了对比分析，重点研究了固化前土颗粒的形态特征、固化后水泥土内部的形貌特征等，探讨了土颗粒、水泥、聚丙烯酰胺材料之间的理化作用，从而得到聚丙烯酰胺水泥土材料的固化机理。
[Abstract]:Cement-soil material is a kind of green economic environmental protection building material, which is widely used in many projects. However, this material has some defects and shortcomings, so it still needs to be further studied. In this paper, the strengthening mechanism and durability mechanism of polyacrylamide on cement soil are analyzed by means of the experimental study on strength and durability of cement soil with polyacrylamide. In this paper, the unconfined compressive strength of cement samples with different polyacrylamide content was measured. The results showed that: with the increase of polyacrylamide content, The strength of cement soil increases first and then decreases, which proves that there is an optimal content when the content of polyacrylamide is lower than 10, and when the content of polyacrylamide is suitable, the molecular concentration of cement soil is moderate, which can improve the surface properties of soil particles. The cement-soil has the function of strengthening the strength of cement-soil, but when the content of polyacrylamide is too high, the molecular concentration in the cement soil is too large to form an effective combination between the molecules. The adhesion between soil particles has been greatly weakened, and some soil particles have been separated from the whole structure, which makes the integrity of cement soil obviously lower, which leads to the decrease of strength of cement soil. Secondly, dry-wet cycle test and freeze-thaw cycle test were carried out in each test group. The results of dry and wet cycle test showed that the surface erosion of cement soil decreased gradually with the increase of polyacrylamide content, and the ability of material to resist dry and wet cycle was strengthened. The results of freeze-thaw cycle test show that polyacrylamide can significantly improve the mechanical properties and durability of soil in freeze-thaw cycle environment. Finally, the microstructure characteristics of soil before and after solidification are compared and analyzed. The morphology of soil particles before and after solidification, the morphology of cement soil after solidification and so on are studied, and the soil particles, cement, and so on are discussed. The physicochemical effect of polyacrylamide material, so as to obtain the solidification mechanism of polyacrylamide cement soil material.
【学位授予单位】：内蒙古农业大学
【学位级别】：硕士
【学位授予年份】：2013
【分类号】：TU521.3

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