适用于氯氧镁水泥的聚羧酸减水剂合成及性能研究

发布时间：2018-04-25 06:42

本文选题：氯氧镁水泥 + 流变性　；参考：《长安大学》2017年硕士论文

【摘要】：混凝土工作性对混凝土搅拌、运输、摊铺均有很大影响,良好的工作性能够保证混凝土施工的顺利进展,带来良好的使用性能,有效避免裂缝、沉陷等路面病害的发生。但目前对氯氧镁水泥工作性研究很少,且市售聚羧酸减水剂在氯氧镁水泥中的减水率仅仅10%左右,甚至低至5.5%。鉴于此,本文首先用三种流变模型拟合试验所得的基准氯氧镁水泥浆体流变曲线,选出最佳流变模型。其次,设计并合成了一系列聚羧酸减水剂,通过氯氧镁水泥净浆流动度及流动度经时损失试验确定了适合氯氧镁水泥的聚羧酸减水剂合成条件,并对其进行优化。最后,对合成减水剂在氯氧镁水泥中的应用效果进行了评价。论文所得主要结论为:(1)确定了最适合氯氧镁水泥流变性研究的模型为Power-law模型,掺入减水剂是提高氯氧镁水泥体系流动性最有效的方法;(2)当醚A:醚C:酸:链转移剂=3:1:24:4,合成温度为T3,引发剂用量为单体质量的2%时,合成的减水剂使氯氧镁水泥体系流动度提高程度最大,经时损失最小;(3)用0.25%HN-C配合0.6%合成减水剂使用,解决了体系经时损失大这一问题,提高了氯氧镁水泥强度及耐水性;(4)减水剂的掺入优化了氯氧镁水泥结构,增加了强度相5·1·8晶体的含量,其中合成减水剂和HN-C复配使用后5·1·8相含量大于单掺合成减水剂的,大于基准的。
[Abstract]:The workability of concrete has a great influence on the mixing, transportation and spreading of concrete. Good workability can ensure the smooth progress of concrete construction, bring good performance, effectively avoid cracks, subsidence and other road surface diseases. However, little research has been done on the workability of magnesium oxychloride cement, and the water reducing rate of polycarboxylic acid superplasticizer in magnesium oxychloride cement is only about 10%, or even as low as 5.5%. In view of this, three kinds of rheological models were used to fit the rheological curves of the benchmark magnesium oxychloride cement paste, and the optimum rheological model was selected. Secondly, a series of polycarboxylic acid superplasticizers were designed and synthesized, and the synthesis conditions of polycarboxylic acid water reducers suitable for magnesium oxychloride cement were determined and optimized by the test of flowability and flowability of magnesium oxychloride cement. Finally, the application effect of synthetic water reducing agent in magnesium oxychloride cement was evaluated. The main conclusion of this paper is: (1) Power-law model is the most suitable model for the rheological study of magnesium oxychloride cement. Adding water reducer is the most effective way to improve fluidity of magnesium oxychloride cement system.) when ether A: ether C: acid: chain transfer agent is 3: 1: 24: 4, synthesis temperature is T3, initiator dosage is 2% of monomer mass. The fluidity of magnesium oxychloride cement system was increased by the synthesized water reducer, and the time loss was minimized by using 0.25%HN-C in combination with 0.6% synthetic water reducer, which solved the problem of large time-lapse of the system. The structure of magnesium oxychloride cement was optimized by increasing the strength and water resistance of magnesium oxychloride cement. The content of 518 crystals in the strength phase was increased, and the content of 518 phase was higher than that of only mixed superplasticizer after the use of synthetic water reducer and HN-C. Greater than the benchmark.
【学位授予单位】：长安大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TU528.042.2

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