Prediction of creep behaviour from temperature-accelerated load relaxation behaviour of a polypropylene geogrid

Abstract

Nowadays, geosynthetic-reinforced soil (GRS) structures have been widely adopted. The most important concern on durability characteristic of geosynthetic reinforcements is creep behaviour. Conventional creep test is normally used to determine the creep behaviour of polymer geosynthetic reinforcements, but it is highly time-consumed. As a result, a temperature-accelerated technique has been introduced. The results of short-term creep test (~ 24 hours) can predict long-term creep behaviour. Furthermore, a concept to predict creep behaviour of geosynthetic reinforcements from their stress relaxation behaviour was introduced from the past studies. The results showed that the time history of creep strain (~ 8 hours) can be predicted from the results of stress relaxation tests performed for a much shorter period (~ 3 hours). In this study, the combination between temperature-accelerated test (i.e., Stepped isothermal method (SIM) for creep and Time-temperature superposition method (TTS) for stress relaxation) and prediction of creep behaviour from stress relaxation behaviour was conducted. The results of the temperature-accelerated stress relaxation for the total time-consumed period of 12 hours can predict time history of irreversible strain for about 115 hours. After that, this result can predict the time history of creep strain of 348 hours. With the combined method introduced in this study, the consumed time can be saved for about a factor of 29.