聚天冬氨酸的改性及其在混凝土中的应用研究

发布时间：2018-07-31 17:04

【摘要】：本论文主要通过不同有机改性物对聚天冬氨酸(PASP)开环接枝,分别在支链中接入不同的基团,解决了PASP减水剂原有的强烈缓凝作用和较低减水率等问题,提高了混凝土早期强度和减水率,并保持了原有的含泥敏感性小、保坍性好等优点。国内外对PASP和改性PASP的研究主要集中在医学、污水处理、农业化肥等方面,在水泥和混凝土中的应用未见相关文献。所以,本论文将改性聚天冬氨酸应用到水泥和混凝土具有非常高的创新性和独立性。试验采用A、B、C、D四种有机物对三种不同分子量聚天冬氨酸开环改性,分别在支链中引入A、B、C等基团,同时,也增加了支链的分子量。通过控制改性聚天冬氨酸的合成条件,如;温度、时间、摩尔量等因素,确定了最佳合成方案。论文选定了三种减水效果较好的改性物,分别是AS、AY、BS,并将其应用到水泥净浆和混凝土中研究,通过测定不同掺量净浆的减水率和流动性,混凝土坍落度及经时损失、不同龄期抗压强度、含泥敏感性、耐久性等,评定了PASP改性以后的性能。论文还利用了傅里叶红外分析仪、八通道微量热仪、zeta电位仪等对三种改性PASP进行了微观分析。通过红外分析仪,证明了乙醇胺和牛磺酸的接枝成功性;利用了八通道微量热仪,证实了改性后早期较快的水泥水化作用;通过zeta电位仪,分析了PASP改性前后的减水机理。试验结果表明,三种改性PASP改善了强烈缓凝作用和提高了外加剂减水率,并保持了原有的含泥敏感性小、保坍性好等优点。
[Abstract]:In this paper, different organic modifiers were used to open and graft polyaspartic acid (PASP), and different groups were inserted into the branched chain, which solved the problems of strong retarding effect and low water reducing rate of PASP water reducer. The early strength and water reduction rate of concrete are improved, and the advantages of low sensitivity of mud and good collapse retention are maintained. The researches on PASP and modified PASP are mainly focused on medicine, sewage treatment, agricultural chemical fertilizer and so on. There is no related literature on the application of PASP and modified PASP in cement and concrete. Therefore, the application of modified polyaspartic acid to cement and concrete is highly innovative and independent. Three kinds of polyaspartic acid with different molecular weight were modified by four kinds of organic compounds in the experiment, and the group Anb Bu C was introduced into the branched chain respectively, and the molecular weight of the branched chain was also increased. By controlling the synthesis conditions of modified polyaspartic acid, such as temperature, time, molar amount and so on, the optimum synthesis scheme was determined. In this paper, three kinds of water reducing modifiers, ASAYYBSs, are selected and applied to cement paste and concrete. By measuring the water reducing rate and fluidity, slump and time loss of concrete, The compressive strength, mud sensitivity and durability of PASP were evaluated at different ages. Three kinds of modified PASP were analyzed microscopically by Fourier infrared analyzer and 8-channel microcalorimeter Zeta potentiometer. The graft of ethanolamine and taurine was proved by infrared analyzer, the hydration of cement was confirmed by using 8-channel microcalorimeter, and the mechanism of water reduction before and after modification of PASP was analyzed by zeta potentiometer. The experimental results showed that the three modified PASP improved the strong retarding effect and the water reducing rate of the admixture, and maintained the advantages of low sensitivity to mud and good collapse retention.
【学位授予单位】：石家庄铁道大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TU528;TQ316.6

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