EFFECTS OF TEMPERATURE ON ELASTIC STIFFNESS OF A HDPE GEOGRID AND ITS MODEL SIMULATION

Abstract

One of the important factors that affect the mechanical properties of polymer geosynthetic reinforcement is the ambient temperature. With an increase in the temperature, the rupture strength and the elastic stiffness decrease. In this study, to understand the temperature effects on the load-strain-time behaviours of a polymer geogrid, a series of tensile loading tests were performed on a high-density polyethylene (HDPE) geogrid at different but constant temperatures, and also under step-increasing temperature conditions. The test results revealed that the elastic stiffness of tested geogrid increases with the load level, while decreases with the ambient temperature. These properties were modelled based on the framework of hypo-elasticity. An existing non-linear three-component (NTC) model, which can simulate the load-strain-time behaviours of many types of polymer geogrid subjected to arbitrary loading histories (e.g., monotonic loading at different rates, creep or sustained loading, load relaxation) under a constant temperature, was modified to account for the dependency of the elastic stiffness on the load level and the temperature, as well as the dependency of the rupture strength on the temperature. The modified model can simulate very well the observed temperature effects on the elasticity of the tested geogrid.