Shrink-swell potential, hydraulic conductivity and geotechnical properties of clay materials for landfill liner construction

Abstract

A b s t r a c t. This paper presents studies concerning the applicability of two clay materials for the construction of a sustainable landfill liner. The studies consisted in determination of basic characteristics of the materials, eg particle size distribution, bulk density, particle density, total porosity, pore size, mineralogy, specific surface area, nanoparticle size, and Atterberg limits, as well as measurements of their geotechnical and hydraulic parameters, such as in situ saturated hydraulic conductivity, modules of primary and secondary compression, cohesion, and angle of internal friction. Furthermore, the effects of compaction performed by the Proctor method at various water contents on swelling and shrinkage characteristics and saturated hydraulic conductivity were investigated in order to determine the compliance with the national requirements for selection of material for landfill liner construction. The determined characteristics and geotechnical parameters of the tested clay materials allowed qualifying them as suitable for municipal landfill construction. The shrinkage potential of the tested clays observed was rated as moderate to very high. The cyclic drying and rewetting of the clay materials performed resulted in a significant increase in saturated hydraulic conductivity. Thus, the clay sealing layers, as part of a multilayer liner, should be very carefully operated, preventing the drying out of the clay sealing and assuring the possibility of its constant saturation.

Clays of Different Plasticity as Materials for Landfill Liners in Rural Systems of Sustainable Waste Management

“…Hence, the long-term performance of a landfill liner, limiting possible streams of pollution, is, in our opinion, strongly reliant on three interrelated characteristics of the applied compacted earthen material, related directly to its particle composition, mineralogy, Atterberg limits, plasticity and compaction initial water content: hydraulic conductivity under natural conditions and after compaction, swell-shrinkage characteristics and, finally, the ability of soil/substrate to sustain its hydraulic conductivity after cyclic changes of saturation, resulting in repeated shrinkage and swelling, commonly leading to serious cracking [24,34,35,38,40,41,[45][46][47]. In our opinion, it is also important that the above-mentioned characteristics are easy to determine and measure, without the sophisticated laboratory and field equipment and may be easily understood.…”

Soil type and land use effects on tensorial properties of saturated hydraulic conductivity in northern Germany

“…The well-known multidimensional fluxes in structured soils (Vogel, Gerke, Zhang, & Van Genuchten, 2000) can be caused by varying particle sedimentation (Buczko, Gerke, & Hüttl, 2001;Ritsema & Dekker, 1994), anthropogenic constructions (e.g., waste deposit sealing layers) (Beck-Broichsitter, Fleige, & Horn, 2017;Widomski et al, 2015), glacial processes (Hartge & Horn, 2016), chemical precipitation or biological processes (Rogasik, Schrader, Onasch, Kiesel, & Gerke, 2014). Soil tillage and induced stressstrain processes result in soil deformation and the formation of a platy structure with pronounced differences in flow intensity and directions (Alaoui, Lipiec, & Gerke, 2011;Babel, Benecke, Hartge, Horn, & Wiechmann, 1995;Hartge & Horn, 2016;Horn, Fleige, Zimmermann, & Peng, 2017;Mordhorst, Peth, & Horn, 2014).…”

Suitability of Boulder Marl and Marsh Clay as Sealing Substrates for Landfill Capping Systems—A Practical Comparison

“…The major aim of a landfill capping system is to restrain gas migration (e.g., carbon dioxide and methane), to minimize leachate generation in order to protect groundwater (precipitation contaminated with heavy metals or polycyclic hydrocarbons) by (a) high water storage capacity for the recultivated layer and (b) low hydraulic conductivity and negligible small shrinkage-crack formation potential for top and bottom liners [4,5]. Therefore, the plant-available water capacity and saturated hydraulic conductivity are considered essential properties of mineral sealing substrates (i.e., boulder marl and clay) according to a past paper [2].…”

“…Therefore, the plant-available water capacity and saturated hydraulic conductivity are considered essential properties of mineral sealing substrates (i.e., boulder marl and clay) according to a past paper [2]. These substrates are often used as landfill liners in combination with geosynthetics and geotextiles to ensure long-term hydraulic stability of the landfill capping systems [5,6].…”