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以改性废旧聚苯乙烯塑料高效减水增强剂为基的早强型水泥高效减水剂的研究 总被引:4,自引:0,他引:4
以自己改性合成的改性聚苯乙烯塑料高效减水增强剂为基础 ,利用调配技术 ,与水泥早强剂、普通减水剂复配制备综合性能优良的早强型高效减水剂。研究了配方中各组分对水泥混凝土性能如早期强度、减水率和最终强度的影响 相似文献
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影响改性聚苯乙烯废塑料高效水泥减水剂减水增强性能因素的研究 总被引:1,自引:0,他引:1
通过化学改性反应将废旧聚苯乙烯塑料改性成为可提高水泥混凝土流动性能和强度的高效水泥减水增强剂。研究了改性废旧聚苯乙烯塑料减水剂中离子含量、减水剂的添加量对水泥混凝土的减水率和水泥强度的影响 相似文献
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聚羧酸共聚物侧链结构对水泥水化及硬化过程的影响 总被引:13,自引:0,他引:13
以聚乙二醇系列、丙烯酸、顺酐、丙烯酸羟乙酯为原料合成聚羧酸减水剂,讨论聚羧酸共聚物侧链长度对水泥分散性能和水化过程的影响,并测试掺加减水剂的混凝土性能.实验结果表明:通过调整聚羧酸共聚物中侧链链长的比例使其具有最佳的分散性.实验合成的聚羧酸共聚物聚乙二醇侧链为nPEG600∶nPEG400=1∶1时,分散效果最好,水泥浆体的流动度及分散力最佳,分别为289 mm和10.36.聚羧酸减水剂具有缓凝特性,能够显著延缓水泥水化及硬化过程,使水泥石的后期水化更充分、水化产物结构更紧密更有力量,各龄期混凝土抗压强度都有较大提高.在水泥中添加0.3%聚羧酸减水剂(PEG600∶400),32.5#水泥3 d,7 d和28 d的抗压强度分别提高了50.4%,40.8%,35.1%,42.5#水泥3 d,7 d,28 d的抗压强度分别提高了16.7%,31.0%和22.3%. 相似文献
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改进型聚丙烯酸系高效减水剂的合成 总被引:2,自引:0,他引:2
根据分子结构设计原理,合成了一种改进型聚丙烯酸系高效减水剂(PC-C),对影响减水剂性能的几个关键因素进行了探讨,并用红外光谱表征了其分子结构。通过正交实验获得了最佳的合成参数:乙烯基磺酸钠(SVS):丙烯酸(AA):丙烯酸聚乙二醇单酯(PEA)=1.5:5:3,过硫酸铵(APS)用量为单体总质量的3%;同时研究了减水剂侧链和掺量对分散性能的影响。结果表明:采用甲氧基聚乙二醇(MPEG)作为接枝侧链合成减水剂的分散能力优于采用聚乙二醇(PEG)合成的减水剂;PC-C低掺量即可发挥高分散性能,分散保持性能随掺量的增加而得以提高。 相似文献
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水泥混凝土中的高性能高分子界面活性剂 总被引:1,自引:0,他引:1
综述了高效减水剂、高效引气减水剂等添加剂型高性能高分子界面活性剂在水泥混凝土中的种类和应用研究进展,对水泥混凝土中的有机硅氟高分子表面活性剂也做了简要的概述。 相似文献
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复合型改性木质素基钻井液用降粘剂的性能研究 总被引:1,自引:0,他引:1
以马尾松硫酸盐制浆黑液为原料,经化学改性制备复合型改性木质素基钻井液用降粘剂,并对其在钻井液中的降粘性能进行实验室评价。研究结果表明,该降粘剂既能发挥无机降粘剂良好的降粘作用,又具有木质素系降粘剂良好的抗温、抗盐效果,具有较好的协同作用。加入0.5%降粘剂的淡水基浆,降粘率可达96.7%。 相似文献
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The physicochemical properties of spent fluidized bed cracking catalyst and its influence on hydration process of cement slurry
were studied. The samples were cement slurries prepared with water/solid=0.5 and additions of used catalyst amounted to 0,
5, 10, 15, 20 and 25%with resp. to the solid. After definite time they were subjected to thermogravimetric analysis (TG, DTG,
DTA) and, in order to determine the progress of reaction with water, the heat of hydration was measured by means of isotherm
calorimetry. The studies disclosed that the spent cracking catalyst is not merely an inactive filler in cement slurries, but
it modifies the course of the hydration process. The spent catalyst is a pozzolana additive and its presence leads to a decrease
of calcium hydroxide contents in the system. The spent catalyst affect on the heat of cement hydration. Small amounts additive
accelerate the process of binding.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
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G. Kakali E. Chaniotakis S. Tsivilis E. Danassis 《Journal of Thermal Analysis and Calorimetry》1998,52(3):871-879
DSC was used in order to evaluate the reactivity of cement raw meal. Two groups of samples were studied: five industrial raw
meals for ordinary Portland cement production, with similar compositions, but differences in granulometry; and five industrial
raw meals for white Portland cement production, with similar granulometric features, but different compositions. The burnability
indices of the samples were correlated with certain data obtained from the DSC curves. It is concluded that the DSC curve
data, and especially the temperature and enthalpy effect of belite formation, are strongly correlated with the burnability
of the cement raw meal. The temperature of belite formation is affected by chemical and mineralogical factors, while the enthalpy
effect is additionally affected by the fineness of the raw meal.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
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张晓 《广东微量元素科学》2011,18(12):61-64
对火焰原子吸收分光光度法定水泥中的铁和锰的方法进行了研究.结果表明,在选定的最佳仪器条件下,测定水泥中铁和锰的RSD分别为0.45%和2.68%,回收率分别为97.0%~99.0%和98.0%~102.0%,该法操作简单、测试快速、结果准确稳定. 相似文献
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El-Said N. Sayed M. S. Mikhail A. S. 《Journal of Thermal Analysis and Calorimetry》2000,63(2):525-532
The thermal stability of solidified NaNO3 salts in bitumen and cement has been investigated for safety considerations in the field of solidification of radioactive
waste. The thermal decomposition of bitumen and cement in presence of NaNO3 in a temperature range 22–650°C has been studied. The fraction decomposed of the pure samples and mixtures showed slow linear
reactions followed by acceleratory and decay stages. Data are analyzed according to both Freeman-Carroll and Coats-Redfern
kinetics to evaluate the activation energy and the order of reactions of all mixtures. It is found that the activation energies
of bitumen and cement were 594 and 203 kJ mol-1, respectively. The order of reactions of bitumen and cement was 2 and 4, respectively. The addition of NaNO3 shortens the duration of the induction period in all mixtures. It was concluded that solidification of radioactive waste
containing NaNO3 in bitumen and cement should be applied in the temperature range 22–300°C. At temperature higher than300°C
solidification should be in cement.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献