Volume 20, Issue 4 (December 1997)
Development of an Accelerated Creep Testing Procedure for Geosynthetics—Part I: Testing
The prediction of the long-term strength of geosynthetics is usually based on 10,000-h extension creep tests. Creep tests at elevated temperatures can accelerate testing duration to a reasonable time frame (1000 h) and the results can be extrapolated to longer time intervals. The paper presents the current state of practice in creep testing of geosynthetics and the development of testing equipment and procedure for accelerated creep tests at elevated temperatures. Creep tests were performed on high density polyethylene (HDPE) and polyester (PET) geogrids typically used in soil reinforcement applications.
Creep behavior at room temperature was first evaluated in 10,000-h tests at various creep loading levels (10 to 45% of ultimate strength of the geogrid Tmax). Accelerated creep tests were then conducted for 1000 h at various controlled temperatures from 24°C (75°F) to 72°C (160°F). These tests were conducted at the same loads to evaluate time-temperature-creep relationships of the geogrid.