旋转黏度计测定水泥浆体静态屈服应力和黏弹性研究

发布时间：2018-01-29 03:57

本文关键词： 静态屈服应力黏弹性恒定剪切速率应力松弛蠕变　出处：《硅酸盐通报》2017年06期 　论文类型：期刊论文

【摘要】：采用旋转黏度计进行了恒定剪切速率、应力松弛、蠕变试验,研究了水泥浆体的静态屈服应力和黏弹性。结果表明:新拌水泥浆体属于带有屈服应力的黏弹性流体,其静态屈服应力为弹性向黏性转变时所对应的剪切应力;恒定剪切速率、应力松弛、蠕变试验均能测试出水泥浆体屈服应力和黏弹性。在恒定剪切速率试验中,新拌水泥浆体的屈服应力测试依赖于测试时剪切速率的选择,剪切速率过小,水泥浆体不出现静态屈服应力,剪切速率过大,测试的静态屈服应力较小;在应力松弛和蠕变试验中,测试出的水泥浆体静态屈服应力较恒定剪切速率试验的精确。对于一个静态屈服应力未知的新拌水泥浆体,可先采用恒定剪切速率试验粗略选择剪切速率和剪切应力范围,之后采用应力松弛或蠕变试验进行精确测试其静态屈服应力。
[Abstract]:The constant shear rate, stress relaxation and creep tests were carried out by rotating viscometer. The static yield stress and viscoelasticity of cement paste are studied. The results show that the fresh cement paste is a viscoelastic fluid with yield stress and its static yield stress is the shear stress corresponding to the transition from elasticity to viscosity. The yield stress and viscoelasticity of cement paste can be measured by constant shear rate, stress relaxation and creep test. The yield stress test of fresh cement paste depends on the selection of shear rate. If the shear rate is too small, there is no static yield stress in cement paste, and the static yield stress is smaller when the shear rate is too large. In the stress relaxation and creep tests, the static yield stress of the cement paste is more accurate than that of the constant shear rate test. The range of shear rate and shear stress can be roughly selected by constant shear rate test, and then the static yield stress can be accurately measured by stress relaxation or creep test.
【作者单位】：太原理工大学建筑与土木工程学院;中南大学土木工程学院;
【基金】：国家自然科学基金(51338001,51278324)
【分类号】：TQ172.1
【正文快照】： 1引言静态屈服应力是水泥浆体流变性能的重要指标之一[1-3],通常采用的测试方法是固定剪切速率剪切水泥浆体,记录下剪切应力随时间的变化,将剪切应力最大值记为水泥浆体静态屈服应力。静态屈服应力是水泥浆体从固体态转变为液态的临界值[2-5]。新拌水泥浆体静态屈服应力来源主

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