Scaling relationships for strip fibre-reinforced aggregates
Scaling relationships for strip fibre-reinforced aggregates
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DOI：
10.1139/cgj-2016-0346
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发表时间：
2017-05-01
影响因子：
3.6
通讯作者：
Powrie, William
中科院分区：
文献类型：
--
作者：
Ajayi, Olufemi;Le Pen, Louis;Powrie, William
先前对随机纤维增强颗粒材料的研究表明，颗粒和纤维的相对尺寸对混合物的宏观力学行为有显著影响。然而，定量数据是稀缺的，而且大多数以前的工作都集中在细砂到中砂上，这使得目前的知识对较大尺寸的骨料（如铁路砟）的适用性存在不确定性。本文利用1/3和1/5比例铁路道砟的三轴试验数据，建立了在不同粒度颗粒材料中达到相同增强效果所需纤维的尺寸和数量的比例关系。研究表明，为了保持尺度上的一致性，纤维含量应该被量化为一个数值（即每粒纤维的数量），而不是一个体积比。进一步表明，如果纤维足够宽，增加纤维长度可以增加混合料对偏应力的抵抗；如果考虑到纤维张力的影响，颗粒基质的应力-应变-强度行为的变化是由与纤维添加相关的孔隙比的变化引起的，这与传统的土壤力学理论在各个尺度上是一致的。
Previous research on random fibre-reinforced granular materials has shown that the relative dimensions of the grains and fibres significantly affect the macromechanical behaviour of the mixture. However, quantitative data are scarce and most previous work has focused on fine to medium sands, leaving uncertainties regarding the applicability of current knowledge to larger size aggregates such as railway ballast. In this paper, triaxial test data on 1/3 and 1/5 scale railway ballast are used to develop scaling relationships for the size and quantity of fibres needed to achieve the same reinforcing effect in granular materials of differing grain size. It is shown that, to maintain consistency across scales, fibre content should be quantified as a numerical (i.e., number of fibres per grain) rather than a volumetric ratio. It is further shown that increasing the fibre length increases the resistance of the mixture to deviator stress if the fibres are wide enough; and that provided an allowance is made for the effect of fibre tension, the changes in the stress-strain-strength behaviour of the granular matrix resulting from the changes in void ratio associated with the addition of the fibres are consistent with conventional soil mechanics theory across scales.