Maximum Dry Unit Weight Research Articles

Suitability Assessment of Selected Lateritic Soils For Highway Construction In Anambra State, Nigeria

Fifteen samples of coarse-grained lateritic soils obtained from different parts of Anambra State were assessed for their suitability as materials for highway construction. The soil samples were subjected to laboratory tests to obtain their index properties, compaction and California bearing ratio (CBR) characteristics. Three compactive efforts namely, British Standard Light (BSL) compaction, West African Standard (WAS) and British Standard Heavy (BSH) compaction were employed in the compaction tests. Samples were soaked for 48hrs prior to CBR testing. The index properties of the soils were used to classify the soils as silty sand (SM) or silty sand/clayey sand (SM-SC) based on the Unified Soil Classification System (USCS) classification as well as silty soils (A – 4) or silty/clayey gravel and Sand (A – 2 -4) based on American Association of State Highway and Transportation Officials (AASHTO) classification. All the fifteen soils fell under “grading F” based on AASHTO standard specification designations for particle size distribution. The maximum dry unit weight (MDUW) of the soil samples ranged from 16.203 kN/m3 to 19.424 kN/m3,17.385 kN/m3 to 19.996 kN/m3 and from 18.126 kN/m3 to 21.473 kN/m3 with corresponding optimum moisture content of 11.4% to 21.4%, 12.45% to 12.5% and 8.5% to 11.75% for BSL, WAS and BSH respectively. The CBR values ranged between 7.92% and 18.87%. Most of the soil (more than 50%) did not meet the lower values of MDUW while only 20% of the soils had CBR values above 10% which is specified for subgrade soils by the AASHTO standard and the Nigerian Highway Design Manual, Federal Ministry of works and Housing.Keywords: coarse-grained, lateritic soils, highway pavement materials, USCS, AASHTO

Effect of Two Organic Chemical Fluids on the Mechanical Properties of an Expansive Clay Soil

Abstract An experimental study was conducted to investigate the effect of two organic chemical fluids (glycerol and acetone) on the mechanical behavior of an expansive clay soil. A number of experimental tests, including Atterberg limits, compaction, free swelling, unconfined compressive strength, California Bearing Ratio (CBR), and one-dimensional consolidation (loading and unloading) tests, were conducted on specimens of natural soil and soil contaminated with pure glycerol and acetone fluids at different percentages (10 %, 15 %, and 20 %) by weight. The results showed that the effect of pure glycerol on the behavior of the contaminated soil is different from acetone. Glycerol caused a reduction of Atterberg limits, free swelling, unconfined compressive strength, CBR, and optimum water content and an increase in maximum dry unit weight, while acetone showed the opposite effects. These variations of mechanical and physical behavior are a function of the percentage of glycerol or acetone. Furthermore, the results of the loading and unloading tests showed that the compression and swelling indexes are independent of the type of organic chemical fluids used. Results from scanning electron microscopy tests confirmed that the effect of glycerol on the behavior of soil is not the same as acetone.

Performance of Raft Foundation under Static Vertical Loading in Contaminated Soil

This study focuses on studying the impacts of residues oil on the geotechnical properties of soil and the performance of raft footing rested on oil contaminated soil and subjected to vertical loads. The contaminant used in the present study is residues oil, which is by product disposed of diesel engine oils. The soil samples are contaminated artificially by soaking with two percentage of disposed engine oil of contaminant consist of (disposed engine oil and gasoline) of 20% weight of dried of intact soil samples to obtain different concentrations of contaminant absorbed by soil samples for 30 days to complete the saturation. The mechanical model manufactured to investigate the behavior of raft footing under vertical static loading rested on intact and contaminated soils. The obtained results detected contaminant content have notable impacts on the physical soil characteristics such as the fine particles, specific gravity, plasticity index, and maximum dry unit weight decreased with the increase of contaminant content than that of intact soil. The mechanical soil properties of soil indicated the increase of the compressibility of soil with increase of residues oil percentage, but the soil strength and stiffness are decreased notably. In addition, the total and permanent settlement of raft footing constructed in contaminated soil samples increased by (27-43) % and by (41-58) % than that of an intact soil sample, respectively.

Characteristics of Engineered Waste Materials Used for Road Subbase Layers

Coal fly ash (FA) and basic oxygen furnace (BOF) slag are the by-products of coal combustion in power stations and steel plants, respectively. The disposal of these wastes would require landfill space and can cause environmental pollution. In order to avoid disposal, the use of FA and BOF slag as sub-base material in highway pavement was investigated. The first part of this research was the characterization of FA and BOF in terms of their chemical and mineralogical compositions as well as the microstructural analysis. This is followed by the preparation of soil mixtures containing different proportions of kaolin, FA, BOF slag (0%, 15%, 20% and 25% by weight) and lime at a constant ratio (5%). Kaolin was used to represent the natural soil. The soil mixtures were cured for 1, 7 and 28 days and some were cured 56 days. At each curing age, the dry unit weight (γdmax), the unconfined compressive strength (UCS) and California bearing ratio (CBR) were determined. X-ray diffraction (XRD) and scanning electron microscopy (SEM) techniques were also used to examine the changes in the phase-mineral composition and microstructure properties, respectively. The results show that the maximum dry unit weight values were observed in the mixture consisting of 25% FA, 15% BOF slag and 5% lime. The XRD analyses of kaolin soils containing, FA, BOF slag and lime exhibited the formation of hydrated products such as portlandite (C-H), calcium silicate hydrates (C-S-H) and calcium aluminium silicate hydrate (C-A-S-H), which increase with the age curing. According to results obtained, FA and BOF slag can be used in road base and sub-base materials.

Recycled Crushed Ceramic Rubble for Improving Highly Expansive Soil

The recycling of waste materials (that polluted the environment) to mitigate and improve the poor geotechnical properties of difficult soils represents one of the sustainable solutions to reduce the negative effects of the waste. The potential for using recycled crushed ceramic rubble (RCCR), from building rubble, as a stabilizer for expansive soil was studied. Five different percentages of two gradations of RCCR were prepared and added to highly expansive soil (HES). The effects of RCCR on geotechnical properties and swelling stages of the soil were investigated. Characterization for the microstructure of natural and stabilized soil was carried out by scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDX). It was found that, regardless of its gradation, RCCR reduces the values of Atterberg limits and optimum water content of the soil. RCCR caused an increase in specific gravity and maximum dry unit weight. The RCCR increased soil strength from 208 to 435 kPa. The curing of HES–RCCR mixtures for 7 days led to significant improvement in strength values. Based on the nonlinear regression, there was a perfect nonlinear relationship found between RCCR and soil strength. On the other hand, RCCR caused 24 to 71% reduction in maximum swelling percent. The magnitude of the total swell decreased by increasing the size of RCCR material or increasing the content of this material, regardless of its size. The mixing of RCCR with HES increased the time required to complete both the initial and primary soil swelling, while the secondary swelling time reduced. However, the maximum RCCR content, to achieve the maximum strength and minimum swell percent, was 30% for both gradations of RCCR. There are compounds with cementation nature formed due to mixing RCCR with HES: such compounds are responsible for the development of strength and mitigation of swell effect. The current results indicate that RCCR is technically practicable in soil stabilization.

Influence of Silica Fume on the Geotechnical Characteristics of Cemented Sand

It is well recognized that the addition of cement to sand is one of the environmental and economic techniques in soil stabilization. However, with respect to silica fume, its impact on the characteristics of cemented sand has not been comprehensively investigated. For this purpose, a series of standard Proctor compaction, unconfined compression, pH and microstructure tests including field emission scanning electron microscope, X-ray diffraction and atomic force microscopy tests were carried out in this research to explore the influence of silica fume on the geotechnical characteristics of cemented sand. Cement in percentages of 3, 5 and 7% and silica fume in percentages of 0, 0.25, 0.5 and 1% by dry weight of sand were utilized. For unconfined compression and pH tests, samples were cured for different curing times of 3, 7, 14, 28, 42 and 56 days. The results indicated that silica fume particles increase maximum dry unit weight of sand–cement mixtures and reduce their optimum moisture content. Moreover, silica fume improves unconfined compressive strength of cemented sand which the impact of this improvement is more obvious for samples with longer curing time. According to the results obtained by unconfined compression and pH tests, it was detected that there are optimum values of curing time and silica fume amount at which strength of silica fume–cemented sand enhances significantly. Furthermore, some relations were proposed between stiffness and unconfined compressive strength of silica fume–cemented sand. Finally, the results of microstructure analysis confirmed the results found through unconfined compression tests.

COMPACTION CHARACTERISTICS OF A FINE-GRAINED SOIL POTENTIAL FOR LANDFILL LINER APPLICATION

Increasing population growth and urbanization results in increased demand for waste disposal processes and facilities that can protect public health and the environment. In the Philippines, there is a great demand to construct sanitary landfills (SLF) with only 387 local government units (LGUs) or equivalent to 23.86% compliant to date with Republic Act 9003 which mandates all LGUs to use the sanitary landfill. The compaction characteristics of a locally abundant fine-grained soil at different compaction energy levels were investigated as part of a broader study in the suitability of the soil as a landfill liner material. Compaction is essential in the preparation of a well-compacted soil liner in a sanitary landfill to avoid or minimize the migration of leachate and thereby reduce the risk of groundwater pollution. The physical properties are determined through a series of laboratory tests which covers the grain-size distribution, specific gravity, Atterberg limits, soil classification, XRD and SEM-EDX. Correlations to estimate the compaction characteristics at any rational compaction energy (E) are developed. The maximum dry unit weight values at different compactive efforts were used to determine void ratios which were then utilized to compute for the saturated hydraulic conductivity using numerical model for hydraulic conductivity for the same soil type. The resulting hydraulic conductivity ranges from 2.30 x 10-7 to 1.20 x 10-7 cm/sec well above the required value in the Philippines as per RA 9003 and its IRR for the intended Category I and II SLFs application

Effects of Low-Density Polyethylene (LDPE) Strips on Some Engineering Properties of Cement-Stabilized Lateritic Soils

The study investigated the compaction and strength characteristics of lateritic soils stabilized with 3% cement and waste sachet water-proof (low-density polyethylene, LDPE) strips. Three (3) lateritic samples collected from Ugwuoba, Nawfia, and Okpuno in Enugu and Anambra states of Nigeria were used in the study. Index properties tests on the samples show that they fall within class A-2-6(1) and A-2-4(0) based on the American Association of State Highway and Transportation Officials (AASHTO) and SM/SC based on Unified Soil Classification System (USCS). LDPE strips were varied at 0, 0.25, 0.5, 0.75, 1, 1.5, and 2% based on the dry unit weight of the soil. Results of unconfined compressive strength (UCS) tests show significant improvement in the strength of the soils at 2 % LDPE strips. Statistical analysis also shows that a significant relationship exists between the percentage of LDPE strips, compactive effort, and maximum dry unit weight (MDUW)/optimum moisture content (OMC), UCS of the soils. The tensile and flexural strength of lateritic soil stabilized with 3% cement can be improved optimally by the addition of 2% of low-cost LDPE strips of aspect ratio (AR) of 10 mm  10 mm.

Influence of Energy on Compaction Characteristics of High Expansive Soils

Each soil type has different behavior with regard to determination of maximum dry density and optimum moisture content and therefore any soil type has its own compaction requirements for experimental purposes and for control the compaction in the field. The general purpose of this study is to a better understanding of the compaction characteristics of high expansive soils, with emphasis on the relationships of moisture content and dry density of high expansive soils at a range of compaction energy levels. To achieve this purpose, high expansive soils samples were subjected to Atterberg limit and a set of laboratory compaction tests to find compaction characteristics namely; maximum dry unit weight and optimum water content of high expansive soils at different compaction energy (compaction effort) for different number of hammer blows per each layer range from 10 to 50, which varied the energy per unit volume from 356 KN/m3 to 1188 KN/m3.Rather than single peak compaction curves, the most achieved compaction curves are an irregular one and half peak compaction curves. According to the comparison results of different compaction energy, it was concluded that the maximum dry unit weight of high expansive soil was not highly affected by gradually increase of applied energy. The results showed that, the maximum dry density of tested expansive soils sample increased from 1.48g/cm3 to 1.6g/cm3 with increase of compaction energy from 356 KN/m3 to 1188 KN/m3.

Comparison of Reduced Modified Proctor vs Modified Proctor

The compaction characteristics between reduced modified Proctor and modified Proctor tests have been compared. The results show that maximum dry unit weight values are comparable for both the tests but optimum moisture content values differ slightly more. For both the tests: optimum moisture content was found to correlate best with liquid limit, and the relationship for maximum dry unit weight with optimum moisture content was found to be almost the same. Since reduced modified Proctor requires less time and 40% less compaction energy as compared to modified Proctor test, it can be considered as a suitable alternative to the modified Proctor test.

Fuzzy-Based Model for Predicting Strength of Geogrid-Reinforced Subgrade Soil with Optimal Depth of Geogrid Reinforcement

A fuzzy logic (FL)–based modeling approach is employed for geogrid-reinforced subgrade soil of unpaved roads. A review of the literature reveals that fuzzy logic has not been used for predicting the behavior of geogrid-reinforced subgrade. This paper presents FL-based two models with fuzzy Triangular and Gaussian membership functions for input and output variables. It consists of eight input parameters/factors, namely, reinforced/unreinforced section, depth of reinforcement, liquid limit, plastic limit, plasticity index, optimum moisture content, maximum dry unit weight, and soaked/unsoaked condition, and California bearing ratio (CBR) as an output parameter. The fuzzy rules are deduced from the experimental data. The laboratory CBR tests were performed on the subgrade soil reinforced with geogrid. The precision of models was examined by comparing the predicted CBR values with the experimental CBR values for Triangular and Gaussian membership functions. The sensitivity analysis reflects a set of dominant parameters. The results indicated a significant improvement in the CBR value of geogrid-reinforced subgrade soil due to the inclusion of geogrid. The range for optimal depth of geogrid reinforcement is found to be 36 to 60% of the thickness of the soil layer. The potentialities of FL were found to be satisfactory.

Effect of Grain Size Distribution on California Bearing Ratio (CBR) and Modified Proctor Parameters for Granular Materials

The California bearing ratio (CBR) and modified proctor parameters (maximum dry unit weight $$\gamma_{{d\left( {\max} \right)}}$$ and optimum moisture content $$w_{{{\text{opt}}}}$$ ) are valuable indicators of the compaction quality of subgrades, embankments and granular fills. In the engineering practice, correlations of these variables with granulometric properties of the soil are required, especially since testing for these variables can be time-consuming when a large number of samples are analyzed. In this work, 20 different granular materials with varying grain size distributions were prepared and tested. Their grain size distribution properties and their parameters CBR, $$\gamma_{{d\left( {\max} \right)}}$$ and $$w_{{{\text{opt}}}}$$ were determined. These results were analyzed along with a compilation of 77 additional experimental results on granular materials reported in the literature. The influence of some granulometric properties on the parameters CBR, $$\gamma_{{d\left( {\max} \right)}}$$ and $$w_{{{\text{opt}}}}$$ was statistically examined, and some correlations were proposed for these variables. Subsequently, it was demonstrated that the proposed correlations show better accuracy tother reported correlations in the literature. Finally, this work ends with some concluding remarks

Experimental Study on Soils Stabilized with Two Types of Plastic Waste

The reuse and recycling rates for plastics are still below desirable values. The valorisation of plastic wastes that presently end in landfills or is incinerated can help to mitigate this environmental problem. There have been studies in soil improvement using plastic waste. Two types of plastic waste were used to assess their ability to improve soil properties for embankment construction and pavement layers. The selected plastic wastes are made from shredded package labels and ground bottles. The main properties of the soils were characterized. Three percentages of plastic waste were used, and the bearing capacity of the soil determined using CBR test (California Bearing Ratio). The results from the tests show that plastic waste stabilization leads to an increase in bearing capacity, expressed in CBR values, for low contents of plastic waste. This increase was more effective for high penetration values. Reduction in the bearing capacity was observed for higher plastic waste contents. Maximum dry unit weight decreased with increasing plastic waste content, whereas expansion increased with increasing plastic waste content.
 Keywords: Soil stabilization, Plastic waste, CBR test, Compaction, Earthworks

Potential Application of Heat Cured Eggshell Powder and Flyash-Based Geopolymer in Pavement Construction

In this research, the application of eggshell powder (ESP) and flyash (FA) as calcium oxide and alumino-siliceous precursors to produce a feasible geopolymer for pavement construction was studied. Effect of heat curing on long-term mechanical strength development of the geopolymer was also evaluated. The ESP is a waste-by-product produced from crushing waste eggshells, whilst FA is a waste-by-product generated from the coal-fired electricity production plant. Geopolymer composites were produced using three activator ratios Na2SiO3/NaOH − 0.5, 1.0, and 2.0 with a fixed 10 M concentration of NaOH. The curing process was done at 50 °C and 80 °C temperatures for 7 days, 28 days, and 56 days. The optimum activator content (OAC) providing the maximum dry unit weight (MDU) was found to increase with an increment in activator ratio and FA replacement ratio. Na2SiO3/NaOH − 2.0 was found as an optimum activator ratio providing the highest unconfined compressive strength (UCS) and the highest split tensile strength (STS). Similarly, optimum precursor ratio providing the highest UCS followed by highest STS was found as ESP50:FA50. Microstructural analysis showed that cementitious products were formed for the ESP-FA geopolymer at the optimum activator ratio and heat conditions.

Assessment and Characterization of Mine Waste and Fly Ash Material for Effective Utilization in Opencast Coal Mines

Coal is a major source of nonrenewable energy in India. Most of the Industries depend on the coal to meet the energy demand of the country. Coal mining is invariably associated with the generation of voids. The voids so generated are often filled with overburden (OB) and waste materials. To enhance the utilization, fly ash (FA) is also being used for filling the voids. However, these operations inevitably require excessive planning and control to minimize the environmental impact of mining. In order to evaluate the impact of backfilling the voids with coal mine wastes and fly ash, Overburden and fly ash materials have been collected from Talcher coalfield. The geotechnical characterization study of overburden (OB) sample and OB+30% fly ash samples have been carried out separately for backfilling. After addition of fly ash, it is observed that the permeability is increased but liquid limit, plastic limit, and plasticity index (PI) of the OB are decreased. The maximum dry unit weight of OB mixture decreases while optimum water content increases with the fly ash. The angle of internal friction of OB decreases after addition of the fly ash. Cohesion value of OB sample has not changed much after addition of the fly ash. The grain size analyses results show OB sample is poorly graded. The OB soil type is found to be poorly graded sand of low compressible clay (SP-CL). Similarly, the OB+30% fly ash soil type is of poorly graded sand of low compressible silty (SP-ML) type. The OB and OB+ 30% fly ash contain heavy metals such as Fe and Al in high quantity, mild concentrations of Zn, Cr, and Mn and low amounts of Cu, Co, As, and Se. B and Pb are found below the detection level. The decreasing order of heavy metals in the leachate samples observed to be Fe>Mn>Ni>Cu>Zn>Se>Co>Cd>Cr>As. The major mineral phases in OB and OB+30% fly ash samples are found to be quartz, kaolinite, muscovite, dickite, zinnwaldite, and illite.

An experimental study on micro-structural and geotechnical characteristics of expansive clay mixed with EPS granules

Pavement structures constructed on the expansive soil subgrade experience a higher upward pressure compared to any other subgrade material. The upward pressure is caused due to high swelling and shrinkage characteristics of expansive clay soil. The present study has investigated and identified the mechanisms by which a remolded expansive soil can be modified to reduce the upward pressure and swelling (heave). To achieve this, a lightweight, environmentally friendly, and high pressure resistive expanded polystyrene (EPS) granules have been used with expansive soil s from three different locations of Madhya Pradesh state, India. The study has been performed to understand the swelling and strength characteristics of soil with and without the use of EPS (density = 21.6 kg/m3) as per ASTM specifications. The chemical and microstructural components of the expansive soil were investigated using autotuned total reflectance Fourier transform infrared (ATR-FTIR), X-ray diffraction (XRD), and scanning electron microscope (SEM). Several laboratory experiments, including optimum moisture content, maximum dry unit weight, grain-size distribution, liquid limit, plastic limit, shrinkage limit, free swell index, unconfined compressive strength, and pressure swelling tests were carried out on the statically compacted expansive clay soil specimen with and without EPS (0.25%, 0.50%, 1.00%). The maximum addition of EPS was considered as 1% as the very high expansion was observed, and beyond this, further addition of EPS was not feasible. The results show that the swelling pressure, expansion percentage, and time rate of swell decrease, whereas the unconfined compressive strength (UCS) increases with the addition of EPS. The inclusion of EPS in expansive clay soil exponentially reduced the heave and the upward pressure, whereas the maximum UCS was observed at 0.5%.

Enhancement of the Geotechnical Properties of Soils Using Marble and Lime Powders, Guelma City, Algeria

As quality soils become scarce and their location is more difficult and expensive, it becomes increasingly necessary to improve soil quality through soil stabilization. The benefits of energy saving and resource conservation, effective recycling of all solid wastes (fly ash, slag, lime, marble dust, etc.) has become a global concern that requires research and development. This article presents the results of a laboratory tests to investigate the effects of marble powder and lime on compaction characteristics, Atterberg limits, shear strength parameters, and unconfined compression test of two Algerian soils. Marble powder and lime are added in varying percentages (2%, 4%, and 6% by weight) to the soil samples. Test results reveal that the liquid limit and plasticity index decrease, whereas the plastic limit increases with the addition of lime and marble powder for soil A and soil B, in which the decrease is more significant with soil A than soil B. The unconfined compressive strength increased with increasing curing time and percentages of lime and marble powder for the two soils. The highest unconfined compressive strength was achieved at 6% marble powder for soil B after 28 days. The addition of marble powder for both soils decreased the optimum moisture content and increased the corresponding maximum dry unit weight. However with lime addition, both soils show decrease in the optimum moisture content and in the corresponding maximum dry unit weight. The shear strength parameters increased for both soils with increase of lime percentages. Whereas for the addition of marble powder, there is an increase of friction angle and decrease of cohesion for soil A. There is considerable change for soil B with marble powder, a decrease in friction angle and an increase in cohesion. The results show that marble powder could be used as a stabilizer for soils with high clay content and known mineralogy composition. In addition, it is very important to get rid of its negative effect on environment and to obtain economical benefit from it.

Shear strength parameters of peat soil of district of Asahan by direct shear test

Peat is a wetland ecosystem characterized by the accumulation of organic matter happens for a long time. This accumulation occurs because of the slow decomposition rate compared to the rate of accumulation of organic found in the wetland forest. The purposes of this study were to determine the index properties, to classify the peat soil classification, to obtain the optimum water content and maximum dry unit weight, γd by Standard Proctor test, and to examine the shear strength of peat soil by direct shear test. The peat soil had water content, w of 726.34 % and a specific gravity, Gs of 1.302. Based on ASTM D4427-92, the classification of peat soil was high ash peat and highly acidic. Based on the Standard Proctor test, the optimum water content obtained was 34% and the maximum dry unit weight was 0.518 gr/cm3. The Standard Proctor test increased the value of the dry unit weight of the undisturbed soil samples from 0.154 gr/cm3 to 0.556 gr/cm3. The original internal friction angle, ϕ and cohesion, c were 0.595º and 0.019 MPa while the Standard Proctor test resulted in 3.539º of internal friction angle, ϕ and 0.020 MPa of cohesion, c.

Effect of compaction and direct shear test values on peat soil of Batubara Regency, Sumatera Utara Province

Peat soil is an organic soil and is usually found in low-lying areas where the water table is near the ground surface. The peat Soil has very large water reserves, high compression and has a low carrying capacity. This study aims to ascertain the index properties, to classify the peat soil classification according to ASTM 4427-92 (2002), to get the optimum water content and maximum dry unit weight by Standard Proctor test, and to analyze the shear strength of peat soil by direct shear test. The peat soil had water content (w) of 752.833 % and specific gravity (Gs) of 1.533. According to ASTM 4427-92 (2002), the peat soil was classified as high-ash peat with more than 15 % ash and as slightly acidic peat with a pH between 4.5 and 6.5. From the Standard Proctor test, the peat soil had an optimum water content of 37.235 % and 0.474 gr/cm3 maximum dry unit weight (γdmax). The Standard Proctor test increased the value of the dry unit weight (γd) of 0.169 gr/cm3 to 0.519 gr/cm3. The original internal friction angles (φ) and cohesion (c) were 0.885º and 0.015 MPa respectively while the Standard Proctor test resulted in 5.294º of internal friction angle (φ) and 0.023 MPa of cohesion (c).

Treatment of Dredged Sediments of Bouhanifia Dam for Their Valorization in Passive Barrier of Landfill

In Algeria, the construction of landfill has increased in recent years because of the growth of wastes of all kinds. To realize passive containment barriers during the construction of these centers, a study was conducted on the natural dredged sediments of the Bouhanifia dam (western Algeria), from the settling ponds during their storage. These sediments were treated at different percentages of bentonite (2, 4, 6, 8 and 10%). For each percentage, 2 samples were tested. A series of experimental laboratory tests were conducted to investigate the effect of bentonite content on the geotechnical and hydraulic characteristics of the sediments. The study was carried out on samples compacted under Modified Optimum Proctor (MOP) conditions, MOP ± 3% with water and landfill leachate. The results show that the compaction characteristics were affected by the addition of bentonite, the optimum water content increased and the maximum dry unit weight decreased in the presence of a large amount of bentonite. Atterberg limits increased, and permeability, measured by Falling-Head and Oedometer tests, decreased with treatment, suggesting that bentonite-treated sediments can be used as passive clay barriers for a landfill of hazardous waste.