LOAD-STRAIN-TIME BEHAVOURS OF TWO POLYMER GEOGRIDS AFFECTED BY TEMPERATURE

Abstract

A special series of tensile loading tests was performed on two types of geogrid using a wide
variety of load and temperature histories to evaluate the effects of ambient temperature on their load-strain-time
behaviours. The applied loading schemes included monotonic loading and sustained loading under different
controlled ambient temperature conditions. The followings were found from test results and their analysis
performed in this study. With an increase in the ambient temperature, the rupture strength and stiffness decreased
while the creep strain increased associated with a decrease in the stiffness. The creep strain by sustained loading
during which the temperature was elevated from 30 oC to 50 oC was significantly larger than the one by
sustained loading during otherwise monotonic loading at the constant temperature equal to either 30 oC or 50 oC.
The elastic stiffness decreased with an increase in the temperature while increased with the tensile load level.
Importantly, the residual tensile strength observed at the same ambient temperature was essentially independent
of pre-rupture loading histories.