Strength and hydraulic conductivity characteristics of sand-bentonite mixtures designed as a landfill liner

Compacted sandy soils with addition of bentonite have been used in a variety of geotechnical structures as engineered barriers,such as in landfill liners and hydraulic containment structures. in this study,igbokoda sand was mixed with bentonite at varying percentages of 0%,2%,4%,6%,8% and 10% by weight of sand. strength tests,which include compaction test,california bearing ratio (cbr) test and direct shear test,were performed on various sand-bentonite mixtures using standard methods. hydraulic conductivity tests were also performed on various sand-bentonite mixtures in order to determine their suitability as landfill liner. results from the tests showed that 8% of bentonite with sand mixture had a hydraulic conductivity below 1×10-7 cm/s,a cohesion value of 250 kn/m3 and a reasonable strength (cbr) value of 54.07% using the west africa standard compactive method,hence being the safest of the selected varying percentages for the design of a landfill liner. © 2017 just. all rights reserved.