Micro-scale tensile properties of single geotextile polypropylene filaments at elevated temperatures

摘要

Geotextiles are porous and fibrous materials that consist of randomly oriented and isotropically distributed long filaments which vary in terms of spatial distribution, curvature, orientation, size, and mass density. The heterogeneous internal structure of geotextiles constituted from individual/discrete fibers and having different micro-structure and macro-structure properties are prone to exhibit dissimilar tensile stress-strain behavior (i.e. progressive versus reactionary) as well as showing favorable versus adverse response to varied experimental conditions such as temperature and strain rate change when tested at macro scale as opposed to micro-scale level. To this end, in order to evaluate thermo-tensile strength properties as well as to characterize tensile extension behavior of single geotextile filaments at micro-scale level, micro-mechanical tensile tests were performed at different temperatures using a Dynamic Thermo-Mechanical Analyzer (DMA) on single filaments extracted from polypropylene needle punched nonwoven geotextile. Various test temperatures between 21 ℃ and 50 ℃ were chosen to represent and simulate the wide range of temperatures encountered in the field for geotechnical applications such as landfill base liners. The paper also presents a statistical analysis of the results of the test program to provide a basis for comparison of inherent filament variability.