Recent findings indicate that the effect of superplasticizers on decreasing the yield stress of cementitious suspensions is attributed to the modification of percolation threshold in addition to interparticle force. These dual effects complicate the assessment of yield stress dependence on the superplasticizer type and dosage, as yield stress can no longer be expressed as a separable function of interparticle forces and the number of interacting particles. To address this challenge, our study proposed scaling laws that directly linked yield stress to the surface coverage of superplasticizer by incorporating the percolation threshold into the interparticle force function. The scaling relation between surface coverage and viscosity was moreover established. At low surface coverages, the combined contributions of interparticle force and percolation threshold to the yield stress were characterized using the square of polymer devoid contact frequency. Furthermore, the viscosity varied linearly with the square root of this frequency, scaling with the quarter power of yield stress. In the high surface coverage regime, the yield stress was linearly dependent on the polymer devoid contact frequency given the limited variation of interparticle force. The proposed scaling laws can account well for the rheological property dependences on superplasticizer adsorption over a wide range of cement suspensions, holding significant values for controlling the yield stress and viscosity of cement-based materials in industrial practice.

中文翻译：

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对水泥浆流变特性的表面覆盖依赖性的新见解：测量和结垢分析


最近的研究结果表明，高效减水剂对降低水泥基悬浮液屈服应力的影响归因于除颗粒间力外，渗流阈值的改变。这些双重效应使屈服应力对高效减水剂类型和用量的评估变得复杂，因为屈服应力不能再表示为颗粒间力和相互作用颗粒数量的可分离函数。为了应对这一挑战，我们的研究提出了缩放定律，通过将渗流阈值纳入粒子间力函数，将屈服应力与高效减水剂的表面覆盖率直接联系起来。此外，还建立了表面覆盖率和粘度之间的缩放关系。在低表面覆盖率下，使用聚合物无接触频率的平方来表征颗粒间力和渗流阈值对屈服应力的综合贡献。此外，粘度与该频率的平方根呈线性变化，随屈服应力的四分之一次方而变化。在高表面覆盖率范围内，鉴于颗粒间力的变化有限，屈服应力与聚合物无接触频率呈线性关系。所提出的缩放定律可以很好地解释流变特性对各种水泥悬浮液上高效减水剂吸附的依赖性，对于在工业实践中控制水泥基材料的屈服应力和粘度具有重要价值。