偏高岭土基地质聚合物的研发与应用

发布时间：2018-04-17 05:29

  本文选题：高岭土 + 活性测定　； 参考：《长沙理工大学》2014年硕士论文

【摘要】：地质聚合物作为一种新型材料,在土木工程领域有着广泛的应用。本文通过理论研究,系统地揭示了地质聚合反应的基本原理,并以此为理论根本,以激发效果好、反应速率快、反应完全、生成物强度高等高效的反应机理为出发点,采用山西煤系高岭土为原料,氢氧化钠和硅酸钠为复合激发剂,制备偏高岭土基地质聚合物水泥和地粘结剂,以应用于工程实践。偏高岭土基地质聚合物水泥制备过程中的首要问题就是偏高岭土的活性问题。评定偏高岭土活性的最直接方法是比较生成的偏高岭土基地质聚合物的抗压强度,但该方法周期较长,不利于实用。本文通过对高温煅烧后偏高岭土的DSC-TG分析、XRD分析和NMR分析,讨论了偏高岭土活性与其中活性氧化铝含量的相关性,探索了偏高岭土的高温活化机理和活性测定原理,提出了改进的滴定络合法和紫外分光光度计法并应用于偏高岭土活性测定,进而通过偏高岭土地聚物的力学性能试验予以验证。试验结果表明,煅烧温度对偏高岭土的活性有显著影响,随煅烧温度升高呈现先提高后降低的规律；滴定络合法和紫外分光光度计法可以测定铝的溶出率并且用于偏高岭土活性的快速测定；山西煤系高岭土在煅烧温度800。C,煅烧时间4h的条件下,可以获得最高活性的偏高岭土。选择煅烧后、活性最佳的高岭土为原料,以氢氧化钠和硅酸钠为复合碱性激发剂,制备偏高岭土基地质聚合物水泥。探讨了配合比、养护条件等工艺因素对偏高岭土基地质聚合物的凝结时间和力学性能的影响。研究发现以100g偏高岭土为原料,25g氢氧化钠、30ml硅酸钠(模数2.0)、20ml水为复合碱性激发剂,在养护条件为70℃、60min下,制备的地质聚合物强度最高,达到88.96Mpa。同时使用维卡仪,对地质聚合反应的凝结时间做了系统的研究,发现控制激发剂中各物质的含量可以控制地质聚合反应的凝结硬化时间,并且发现水的用量对地聚物强度影响并不大,但可以通过控制水的用量来控制初凝和终凝时间。最后,以最优配比偏高岭土基地质聚合物作为胶黏剂替代普通环氧类胶黏剂加固钢筋混凝土试件,通过不同温度下的拉伸剪切试验和表层嵌贴CFRP—混凝土界面剪切试验,研究偏高岭土基地质聚合物胶黏剂的拉伸剪切强度和作为CFRP的内嵌粘结剂的强度随温度的变化规律,并与普通环氧类胶黏剂作对比,发现其优势所在。结果发现：在常温环境下,环氧树脂粘结剂的粘结性能优于地质聚合物粘结剂的粘结性能；但在高温环境下,环氧树脂粘结剂的粘结性能明显下降,而地质聚合物粘结剂的粘结性能则基本不受温度变化的影响。这对于将地质聚合物粘结剂用于防火等级较高的结构,有着重要的意义。
[Abstract]:As a new material, geopolymers are widely used in civil engineering.In this paper, the basic principle of geological polymerization is systematically revealed through theoretical research, and the basic theory is based on the high efficiency reaction mechanism, such as good excitation effect, fast reaction rate, complete reaction, high product strength and so on.Using Shanxi coal series kaolin as raw material, sodium hydroxide and sodium silicate as complex activators, the base polymer cement and ground binder of metakaolin were prepared for application in engineering practice.The activity of metakaolin is the most important problem in the preparation of metakaolin base polymer cement.The most direct method to evaluate the activity of metakaolin is to compare the compressive strength of the formed metakaolin base polymer, but this method has a long period and is not practical.In this paper, the correlation between the activity of metakaolin and the content of active alumina in metakaolin is discussed by means of DSC-TG and NMR analysis. The activation mechanism at high temperature and the determination principle of activity of metakaolin are explored.The improved titration method and ultraviolet spectrophotometer method were proposed and applied to the determination of the activity of metakaolin, and the results were verified by the mechanical properties test of metakaolin geopolymer.The results show that the calcination temperature has a significant effect on the activity of metakaolin, and increases first and then decreases with the increase of calcination temperature.Titration complex method and ultraviolet spectrophotometer can be used to determine the dissolution rate of aluminum and rapid determination of the activity of metakaolin, and the highest activity of metakaolin can be obtained under the condition of calcination temperature 800.C and calcination time 4h.After calcination, kaolin with the best activity was used as raw material, sodium hydroxide and sodium silicate were used as complex basic activators to prepare metakaolin base polymer cement.The effects of mixing ratio and curing conditions on the setting time and mechanical properties of metakaolin base polymer were discussed.It is found that the geopolymers prepared by using 100g metakaolin as raw material and 25g sodium hydroxide 30ml sodium silicate (20ml water as composite basic activator at 70 鈩，

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