Geotechnical properties of a natural zeolite

An investigation into the geotechnical properties of a natural, crushed and ground zeolite used as a compacted soil liner in geoenvironmental applications was carried out to ensure adequate strength and permissible compressibility. Tests aimed at examining the influence of gradation, density and stress level on strength show that the zeolite behaves as any granular material with its shear strength in direct shear increasing with density and stress level and decreasing with increasing uniformity. To validate these findings direct shear tests were performed on two quartz sands of similar mean diameter and varying gradations and grain shape. The results of the tests on the zeolite and the sand of similar gradation and grain shape nearly coincide. For the zeolite under consideration, which is mainly composed of clinoptilolite, grain crushing is negligible for stress levels common in engineering construction. Finally, the influence of wetting on the shear strength of the zeolite is insignificant. The results indicate that these materials can be analysed within the framework of behaviour for quartz sands.