Research on Time-Varying Behavior of Cement Grouts of Different Water-Cement Ratios

The thesis presents an research on the time-varying behavior of cement grouts with different water-cement ratio of 0.5,0.55,0.6,0.65,0.7,0.75,0.8,0.9,1.0,1.1,1.25,1.0,2.0,5.0 and10.0 at 0 minute, 5minutes,10minutes,20minutes,30minutes,60minutes,respectively.This was to investigate the time-varying behavior of reheological parameters of cement grouts with different water-cement ratios.It confirmed that: consistency coefficient and viscosity are time-varying reheological parameters, while rheological index and initial stress(yield stress) are time-independent behavior;the flow pattern properties of cement grouts with different water-cement ratios could remain unchanged with time; the laws with time change of consistency coefficient and viscosity of cement grouts accord exponential function, cp(t)=c0×ekt (Power-law fluid) or hp(t)=h0×ekt(Newtonian fluid or Bingham fluid).These research results have very important realistic value and theory meaning.

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Study on the Effects of Different Water-Cement Ratios on the Flow Pattern Properties of Cement Grouts

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.71-78.1264 ◽

2011 ◽

Vol 71-78 ◽

pp. 1264-1267 ◽

Cited By ~ 4

Author(s):

Zhi Quan Yang ◽

Ke Peng Hou ◽

Ting Ting Guo

Keyword(s):

Flow Pattern ◽

Newtonian Fluid ◽

Power Law ◽

Inflection Point ◽

Bingham Fluid ◽

Power Law Fluid ◽

Conversion Point ◽

Cement Grouts ◽

Engineering Practices ◽

Negative Factors

The article presents an study on the rheological properties of cement grouts with different water-cement ratios of 0.5,0.55,0.6,0.65,0.7,0.75,0.8,0.9,1.0,1.1,1.25,1.0,2.0,5.0 and10.0.It was to investigate different water-cement ratios of cement grouts effecting its flow pattern properties, and thus determinate the conversion point of them among Newtonian fluid, Bingham fluid and Power-law fluid. It confirmed that,when take into accounts of all negative factors possibly affecting the experiment, including asynchronous loading steps, water temperature, apparatus deflection and so on, W/C(water-cement ratio) = 0.75 is a inflection point,which Power-law fluid converted into Bingham fluid, while at W/C =1.25 the cement grouts suffered a conversion from Newtonian fluid to Bingham fluid. This research results supplied, improved and expanded the knowledge of the flow pattern properties of cement grouts and conversion condition with different water-cement ratios, and so it has important theory meaning and realistic value and may contributes to the engineering practices.

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Comprehensive Effect of the Time and Water-Cement Ratio on the Rheological Properties of Power-Law Cement Grouts

Geofluids ◽

10.1155/2021/6636708 ◽

2021 ◽

Vol 2021 ◽

pp. 1-12

Author(s):

Yang Zhi-quan ◽

Ding Yi ◽

Mi Ya-peng ◽

Zhu Ying-yan ◽

Yang Yi ◽

...

Keyword(s):

Rheological Properties ◽

Power Law ◽

Great Influence ◽

Exponential Model ◽

Engineering Practice ◽

Optimal Model ◽

Cement Ratio ◽

Consistency Coefficient ◽

Water Cement Ratio ◽

Cement Grouts

The rheological properties of cement grouts are significantly affected by the changes of the time and the water-cement ratio, which determine the diffusion state of grouts in rocks and soils and influence the outcome of projects. In this study, Portland cement grouts with water-cement ratios of 0.50, 0.55, 0.60, 0.65, 0.70, and 0.75 at six moments, including 0 minutes, 5 minutes, 10 minutes, 20 minutes, 30 minutes, and 60 minutes, were evaluated to figure out the comprehensive effect of the time and the water-cement ratio on the rheological properties of power-law cement grouts. The results showed that the water-cement ratio had a great influence on both the consistency coefficient and the rheological index of the power-law cement grouts. The former appeared to have a downward trend with the increase of the water-cement ratio, and the latter appeared to have an upward trend. There was a rising tendency between the time and the consistency coefficient, while the rheological index was less affected by time. The difference between its maximum and minimum values was within 5%. Combined with the perspectives of statistical theory, practical applicability, and accuracy, the exponential model was the optimal model for showing the relationship between the comprehensive effects of the time, water-cement ratio, and consistency coefficient of the power-law cement grouts. The linear model was the optimal model of the rheological index based on the comprehensive effect of time and the water-cement ratio. Based on this, a power-law rheological equation with consideration of the comprehensive effect of time and water-cement ratio was established. The research results could not only improve the rheological theory of power-law cement grouts but also provide technical support for engineering practice.

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