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.