engleski

Determination of shear strength parameters of bentonitic blankets

Numerous commercially manufactured products of bentonitic blankets are available on the worldwide market. They are used in the environmental, transportation and geotechnical engineering. In the environmental applications bentonitic blankets act as a low-hydraulic barrier component on waste disposal sites. From the engineering design point of view, stability analyses of the hydraulic barriers at waste disposal sites are one of the most important issues. Therefore, proper determination of the shear strength parameters of all the barrier components has a huge importance for design engineers. Shear strength parameters of bentonitic blankets are generally obtained from laboratory direct shear tests, but the fund of the published data is limited. Moreover, there is a significant variability of the test procedures used and the results obtained. Therefore, the study of the internal shear strength of one type of bentonitic blankets known under commercial name Claymax 200R was performed. Laboratory testing programme consisted of five series of direct shear tests. Special attention was given to the influence of the specimen hydration procedure and horizontal displacement rate on the shear test results. The analysis of the direct shear test resulted in the suggested determination of the strength criterion for bentonitic blankets in two stages. In the first stage, the shear strength is determined for the displacement rate of 0 mm/min, and in the second stage the variation of the strength with the change of displacement rate is defined. The appropriate laboratory testing procedure is proposed on the basis of the suggested strength criterion.

shear strength; GCL; laboratory tests

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