氯氧镁水泥流变特性研究

发布时间：2018-06-26 08:12

  本文选题：道路工程 + 氯氧镁水泥　； 参考：《长安大学学报(自然科学版)》2017年03期

【摘要】：针对氯氧镁水泥早强快硬特性导致其制备的混凝土存在长距离运输时不易搅拌、难泵送等施工受限问题。通过旋转黏度试验测定了氯氧镁水泥浆体在不同剪切速率下的剪切应力及塑性黏度值,采用幂律(Power-law)流体模型拟合氯氧镁水泥流变曲线,并通过该模型分析氯氧镁水泥材料组成设计参数MgO、MgCl_2、H_2O的物质的量比对氯氧镁水泥浆体的剪切应力、塑性黏度及流变特性的影响。研究结果表明:Power-law模型适用于氯氧镁水泥浆体流变曲线拟合,其拟合判定系数均大于0.9,拟合度高,并且可以对稠度系数、流变指数等流变参数进行较好的描述;氯氧镁水泥浆体的剪切应力随剪切速率的增大而增大,而塑性黏度随剪切速率的增大先迅速降低后趋于平稳;剪切速率相同时,氯氧镁水泥浆体的剪切应力随MgO与MgCl_2物质的量比增大而增大,随H_2O与MgCl_2物质的量比增大而减小;随着水泥水化的进行,浆体剪切应力和塑性黏度均增大,当MgO、MgCl_2与H_2O的物质的量比为7∶1∶15时浆体最稳定。
[Abstract]:In view of the early strength and fast hardening characteristics of magnesium oxychloride cement, the concrete prepared by magnesium oxychloride is difficult to mix and pump in long distance transportation. The shear stress and plastic viscosity of magnesium oxychloride cement at different shear rates were measured by rotating viscosity test. The rheological curves of magnesium oxychloride cement were fitted by Power-law fluid model. The influence of the quantity ratio of MgO _ 2 MgCl _ 2 / H _ 2O on the shear stress, plastic viscosity and rheological properties of magnesium oxychloride cement paste was analyzed by the model. The results show that the w / Power-law model is suitable for fitting rheological curve of magnesium oxychloride cement paste, and its fitting judgment coefficient is greater than 0.9, and the fitting degree is high, and the rheological parameters such as consistency coefficient and rheological index can be well described. The shear stress of magnesium oxychloride cement paste increases with the increase of shear rate, while the plastic viscosity decreases rapidly with the increase of shear rate and then tends to steady. The shear stress of magnesium oxychloride cement paste increases with the increase of the ratio of MgO to MgCl _ 2, decreases with the increase of the ratio of H _ 2O and MgCl _ 2, and increases with the hydration of cement. When the ratio of MgO / MgCl _ 2 to H _ 2O is 7:1:15, the slurry is the most stable.
【作者单位】： 长安大学材料科学与工程学院;青海省交通科学研究院;
【基金】：国家自然科学基金项目(51308062) 青海省重大科技专项项目(2014-GX-A2A) 中央高校基本科研业务费专项资金项目(310831163501,310831172201)
【分类号】：U414
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本文编号：2069777