Current packing models for aggregates are robust but they largely prioritize Particle Size Distributions (PSDs). There may be room for further improvement by incorporating aggregate shape. Here, we image up to 250 unique sand particles from 4 different sands and obtain key shape parameters such as Circularity (C), Roundness (R), and Aspect Ratio (AR). Combining these independent parameters, we introduce a new, fundamental parameter – the Particle Shape Metric (P = C.R/AR). Interestingly, this P has a strong correlation with the Packing Coefficient (R = 0.98), obtained independently from helium pycnometry. Most importantly, P of the sands seems to have a direct influence on the yield stress, compressive strength, and open porosity of a variety of mortar mixtures. These findings highlight the potential role of shape metrics in influencing the granular skeleton of cementitious composites, marking a paradigm shift towards optimizing their workability, strength, and durability.

中文翻译：

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颗粒形状度量 (PSM) 简介：一个基本参数，概括了骨料形状在增强堆积和性能方面的作用


目前的骨料堆积模型很强大，但它们主要优先考虑粒径分布 (PSD)。通过结合骨料形状可能还有进一步改进的空间。在这里，我们对来自 4 种不同沙子的多达 250 个独特沙粒进行成像，并获得关键形状参数，例如圆度 (C)、圆度 (R) 和纵横比 (AR)。结合这些独立参数，我们引入了一个新的基本参数 - 颗粒形状度量 (P = C.R/AR)。有趣的是，这个 P 与堆积系数 (R = 0.98) 具有很强的相关性，该系数是通过氦比重瓶独立获得的。最重要的是，砂的 P 似乎对各种砂浆混合物的屈服应力、抗压强度和开孔率有直接影响。这些发现强调了形状指标在影响水泥基复合材料颗粒骨架方面的潜在作用，标志着优化其可加工性、强度和耐久性的范式转变。