The creep behavior of polyester geogrids
| Autor: | Yi-Tso Tain, 田一佐 |
|---|---|
| Rok vydání: | 2005 |
| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 93 The objective of this study is to investigate the creep behavior and creep reduction factors of various Polyester geogrids. Four types of polyester geogrids were investigated. The ultimate tensile strengths of these geogrids varied from 100 to 400 kN/m. These geogrids were fabricated using knitting and woven techniques. A series of conventional long-term and Stepped Isothermal Method (SIM) tests were performed to evaluate the long creep behavior of the test geogrids. The ASTM D5262 and D6992 test standards were used in the study. The results of the conventional creep tests were used to evaluate the repeatability of the SIM test method. The results of the study indicated that elastic moduli varied from 3992 to 6571 kN/m. The conventional long-term creep strains for 8700 hours were varied from 1.87% and 0.85%. Knitting geogrids shown more creep strain than that associated with woven geogrids. The creep strains for the long-term creep tests were within primary and secondary creep regions. The results of SIM tests showed that a minimum of 6 steps should be used in order to predict the creep behavior beyond 75-year design life. The results obtained from SIM tests could match the results obtained from long-term creep tests better for woven geogrid than those associated with knitted geogrids. Based upon current test data, the creep rupture reduction factors varied from 1.41 to 1.51 for 75-year design life. |
| Databáze: | Networked Digital Library of Theses & Dissertations |
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