| Summary: | 碩士 === 國立屏東科技大學 === 土木工程系碩士班 === 92 === ASTRACT
The objective of this study is to investigate the effect of clamping mechanisms on various tensile tests of high strength geotextiles and related products. Test methods of the ASTM D4632, grab breaking load, ASTM D5035, strip tensile strength, and ASTM D4533, tear strength, were investigated in the study. A high strength Polypropylene slit-film geotextile and a high strength polyester multiple-filament geotextile were used in the study. Typically, mechanical grips using various clamping techniques, such as screw clamping and wedge clamping, were used for a given fabric to prevent slipping of the specimen during a tensile test. Those clamping techniques found to be effective for low strength geotextiles. These techniques sometimes are very time consuming and the tightness of clamping could vary from the operation by different technicians or each operation. However, lower tensile strength was commonly obtained for different types of tensile tests due to specimen slipping for high strength geotextiles. It is also found that the tightness of the clamp has a significant influence on the test results. Test performed by different technicians is an important variable for the test results. Therefore, the conventional apparatus was modified using the hydraulic clamping mechanism. The tensile strength performed using the revised apparatus found to be similar to that associated with the conventional apparatus. However, by evaluation of the standard deviation, the failure shape of the test specimen, and the shape of test curve, there all proved the revised apparatus were effective. In addition, the revised apparatus found to be extremely time saving for performing the grab tensile, strip tensile, and tear tensile tests of high strength geotextiles.
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