基于稳态流变测试的水泥浆体剪切模式研究

发布时间：2018-05-14 20:44

本文选题：稳态测试 + 剪切模式　；参考：《硅酸盐通报》2017年07期

【摘要】：采用RHEORIAB QC型旋转黏度计测定不同剪切方式下水泥浆体稳态流变曲线,并用修正宾汉姆流变模型对其进行拟合,研究了剪切方式对水泥浆体稳态流变测试的影响。结果表明:预剪切对水泥浆体动态屈服应力和塑性黏度影响不大。恒定剪切变形速率小于、等于、大于、偏大于水泥浆体结构抗剪切破坏能力时,剪切应力随时间分别先线性增加接着保持同一值、直接保持恒定值、先减小接着保持同一值、轻微增加后达到平衡。随剪切速率增加,水泥浆体在0.1~100 s~(-1)、100~400 s~(-1)、400~600 s~(-1)三个区段依次呈现出剪切变稀、宾汉姆流体、剪切增稠的流变行为。剪切速率变化范围向剪切变稀或剪切增稠段移动,水泥浆体动态屈服应力减小、塑性黏度增大;单个剪切速率的剪切时间越长,水泥浆体动态屈服应力、塑性黏度均越小。
[Abstract]:The steady state rheological curves of cement paste under different shear modes were measured by RHEORIAB QC rotary viscometer and fitted with modified Bingham rheological model. The effect of shear mode on the steady state rheological test of cement paste was studied. The results show that preshear has little effect on dynamic yield stress and plastic viscosity of cement paste. When the constant shear deformation rate is less than, equal to, greater than, is larger than the shear failure ability of the cement paste structure, the shear stress increases linearly with time and then keeps the same value, directly keeps the constant value, decreases first and then keeps the same value. Achieve balance after slight increase. With the increase of shear rate, the shear thinning, Bingham fluid and shear thickening behavior of cement paste are observed successively in the three sections of 0.1 ~ 100sm ~ (-1) ~ (-1) ~ (400) ~ (-1) ~ (-1) ~ 400 ~ (-1) ~ (-1) ~ (-1) ~ (-1). The range of shear rate changes to shear thinning or shear thickening section, the dynamic yield stress of cement paste decreases and the plastic viscosity increases, while the longer the shear time of single shear rate, the smaller the dynamic yield stress and plastic viscosity of cement paste.
【作者单位】：中南大学土木工程学院;
【基金】：国家自然科学基金(51278497)
【分类号】：TQ172.1

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