Geotechnical properties of a bentonite treated with waste glass grains
Ali Fırat Çabalar, Süleyman Demir
Abstract
This paper presents some geotechnical properties of a bentonite type clay, which was treated with various sizes of waste glass bead additions at various contents. Waste glass beads with two different grains size distributions (fine and coarse) were added to the bentonite at the ratios of 0%, 10%, 20%, 30%, and 40% by dry weight. An intensive series of experimental studies by using standard compaction, fall-cone, and 1D oedometer tests were carried out on the specimens of these mixtures. The compaction results indicate a 7 and 12% increment in maximum dry unit weight (γdrymax) and 19 and 23% decrement in optimum water content (wopt) values of the mixtures with 40% fine and coarse size glass grains, respectively. The fall cone testing results on the specimens would suggest the undrained shear strength (su) values by employing much less water content, which was found to be 35% less in the mixture with 40% fine glass bead addition than that in the clean bentonite. It was also seen that su values of the specimens treated with fine glass bead additions are found to be more sensitive to water changes. Analysis of the oedometer results reveals about 65% decrease in compression index (cc) and swelling index (cs) by 40% glass addition in all specimens, whilst hydraulic conductivity values (k) increase significantly. Accordingly, a substantial contribution has been achieved in improving the bentonite’s behaviour at different levels by placing the glass bead additions at various contents.