Effect of compaction characteristics on hydraulic conductivity performance for sedimentary residual soil mixed bentonite as compacted liners

Abstract

This paper discusses on the compaction effect to the hydraulic conductivity performance for the sedimentary residual soil mixed bentonite. This mixture is proposed as a barrier material in landfill area and may possibly potential materials for use as compacted soil liners in landfills for leachate protection. A laboratories series was conducted to evaluate the effectiveness of compaction characteristics on sedimentary residual soil mixed with different percentage of bentonite (5%, 10% and 15%). The sedimentary residual soil sample was used in this study and was collected in sedimentary residual formation area in Salak Tinggi, Malaysia and named as Salak Tinggi soil. The mixed samples were compacted at three different compaction effort with different energy to determine the maximum dry density (MDD) and optimum moisture content (OMC). Then, the permeability test to determine the hydraulic conductivity (k) was conducted at MDD condition at every compaction effort at effective stress of 100 kPa. The results show that the MDD value were slightly low for the entire soil sample mixed with bentonite at all compaction energy level. Instead it shows all the three different compaction efforts applied to the mixed soil samples with bentonite yielded hydraulic conductivity less (k ≤ 1x10−9m/s). In fact, the increment of bentonite content also resulted in lower of MDD value and hydraulic conductivity value. However, MDD values were found to be higher for mixed soil when compacted with high compaction effort. The results of hydraulic conductivity tests demonstrated that hydraulic conductivity, k ≤ 1x10−9m/s can be achieved just by using lower compaction energy for the soil mix with bentonite. Instead it considered as suitable materials for liner due to the hydraulic requirement for soil barrier, k ≤ 1x10−9m/s. This finding show that compaction efforts play an important role for workability of the mixtures and significantly to be used as compacted of soil liner materials.

Flow through and Volume Change Behavior of a Compacted Expansive Soil Amended with Natural Biopolymers

“…Along the compaction curve, an increasing water content results in clay swelling, thereby increasing the soil compressibility under subsequent loading [40]. The immovable water films around the clay particles decrease the available flow paths for water movement and as such decrease k s [48]. At the maximum γ d , compressibility reaches a minimum value because further reduction in void ratio is difficult to achieve during consolidation [49].…”

Multiple Linear Regression Modelling for the Compaction Characteristics of Sedimentary Soil Mixed Bentonite as Compacted Liner

“…Thus, to maintain the long-term performance of compacted soil liner in landfill area, these two compaction parameters are widely used in compaction criteria for the design and construction of soil liner [2], [3]. The compacted liners commonly used in landfill area as a soil liner used to prevent the groundwater contamination and this soil liner performance is affected by the soil compaction characteristics due to the soil compaction performances is an important role to the requirement of hydraulic conductivity for soil liner to prevent the leachate [4], [5], [6], [7]. Therefore, the compaction of soil needs to be carried out appropriately to avoid the change of soil structure that may lead to the change in soil permeability and the compaction process needs to be performed layer by layer.…”

Effect of solid waste landfill leachate contaminants on hydraulic conductivity of landfill liners

“…The hydraulic conductivity of CCLs and GCLs in landfills is vital in environmental control applications as it controls the transport of high polluting leachate (Sivapullaiah et al 2000;Khalid et al 2020). Soil structure, particle size, specific surface area of the particle, pore size and ratio, as well as the properties of the liquid interacting with the soil are among the factors affecting the movement of contaminants (Stpniewski et al 2011).…”