Characterization of Sand and Zeolite Stabilized Expansive Soil as Landfill Liner Material under Environmental and Climatic Effects

Abstract

This study focusses on the assessment of sand stabilized expansive soil as possible landfill liner materials to be utilized in a semi-arid area. Zeolite was also used as an alternative material to sand, mixing it with the expansive soil forming a stable structure with improved properties. Durability analysis of expansive soil-sand (NS) and expansive soil-zeolite (NZ) mixtures was studied to investigate the climatic and environmental effects on the sustainability of the proposed materials. The climatic effect is studied in terms of cyclic swell-shrinking and the environmental effect, mainly due to temperature elevations in the landfills, is studied in swell-compressibility tests. Cyclic swell-shrink tests and temperature variations (25°C, 40°C and 60°C) were applied on 28-day cured samples of NS and NZ mixtures in order to evaluate their resistance to climatic and environmental changes. Experimental findings showed that swelling potential and axial shrinkage were reduced with the increasing of wetting-drying cycles of both NS and NZ samples. The biggest variation of swell potential and axial shrinkage occurred at 7th cycle for NS (28-d) and 8th cycle for NZ (28-d) soil specimens. Primary swell percentage decreased with the increase of temperature in NS group, whereas, a reverse behavior was observed in NZ group.