Papers by Keyword: Lateritic Soil

Abstract: Increase in the rate of generation of household waste (i.e Municipal Solid waste, MSW) in Nigeria necessitated the growing demand for a safe way to dispose MSW. When MSW comes in contact with water, it generates leachates, a poisonous fluid, that are harmful to humans. The use of landfill system for disposal of MSW has been a good approach for waste disposal. This study evaluated the effect of some hydraulic conductivity (H) parameters (i.e void ratio, degree of saturation and microbial suspension) and permeating fluids on the interaction of lateritic soil subjected to varying steps of treatments with Bacillus coagulans (B. coagulans) and subject to leachate environment for landfill application. Soil was mixed with 0 to 2.4 × 10⁹ cells/ml of B. coagulans. After mixing and compaction, Calcium solution was introduced by gravity on the compacted soil samples and were permeated to percolate to a point of partial saturation. After application of Calcium solution, compacted samples were saturated in water for 24 to 48 hours up until fully saturated, thereafter subjected to H test using water as well as leachate as permeating fluids for a period of 91 days. Results show that void ratio values varied in the ranges 0.550-0.471 and 0.481- 0.485 for specimens where water and leachate were used as permeation fluids. Degree of saturation varied meaningfully with permeation fluids. H values varied in the ranges 1.51 x 10^-9 -1.71 x 10^-9 m/s and 6.84 x 10^-10 - 8.27 x 10^-10 m/s for specimens where water and leachates were used as permeation fluids. Soil-leachate interaction study and micro structural investigations revealed that the modified soil is well-matched with leachate and met the regulatory H value of 1.0 × 10^-9 m/s for used in landfill applications.

Abstract: Reusing industrial waste is a sustainable and eco-friendly way of minimizing environmental pollution in society. In addition, the stabilization of soils with non-conventional stabilizers has been shown to ameliorate engineering features of soils and reduce the cost of construction of road works. This study investigated the impacts of steel slag (SS) on the properties of poor lateritic soil (LS) for road pavement applications. Varying percentages of steel slag from 0-30% of soil dry weight in 5% intervals were employed to stabilize the soil. Plasticity index (PI), Maximum dry density (MDD), Optimum moisture content (OMC), California Bearing Ratio (CBR), Uniaxial Compressive strength (UCS), and chemical composition including the microstructural analysis of the untreated and treated soil were evaluated. With increasing slag content, the PI value decreased significantly from 22.47% to 9.20% indicating a nearly 60% reduction in PI at 20% SS treatment. The soil density became higher with a corresponding decrease in OMC as the SS content increased. The MDD increased from 1.56 g/cm³ for natural soil to 2.10 g/ cm³ at 25% SS content, and further addition of the material reduced the soil density. The CBR and UCS results show a general increase in values with higher SS content. The soaked CBR increased from 11.55 – 22.32% as SS content increased from 0-30%. The 28th day UCS reached the optimum value of nearly 380 kN/m² at 25% SS compared to 93.57 kN/m² of the natural soil. The iron oxide, which is a cementing agent, increased as the content of SS became higher in the soil. The microstructural analysis using scanning electron microscopic (SEM) results showed the formation of larger particles and a reduction in pore spaces as the SS content increased. The 25% SS treated soil satisfies the required 12% PI and minimum soaked CBR of 20% for foundation application as a subbase material in light traffic roads. These results suggest that adding 25% steel slag makes the lateritic soil a suitable material for both subgrade and sub-base pavement layers.

Abstract: This paper investigates an experimental study of cement-stabilized lateritic soil (CSLS) for road construction. The investigation focused on the mechanical properties and the potential of using biomass bottom ash (BBA) as aggregate materials based on the soil-cement standard of Thailand. CSLS specimens were prepared with different contents of BBA (40%, 60%, 80%, and 100%) and hydraulic cement (3%, 5%, and 7%). A series of unconfined compression tests were carried out to present the strength development of the mixtures. The strength development index value indicated the feasibility of using BBA as aggregate materials with the replacement of the lateritic soil (LS) mass by 60% or more. The replacement of LS by BBA of 80% with 5% cement for soil-cement subbase, and 7% cement for soil-cement base courses, is recommended.

Abstract: The impact of admixture of both Ordinary Portland Cement (OPC) and steel slag was examined on the geotechnical properties of the lateritic soil, by conducting basic geotechnical tests: Particle size analysis, Consistency limits, Compaction, California Bearing Ratio (CBR) and Unconfined Compressive Strength (UCS) on both the natural and stabilized soil samples and results were subjected to statistical analysis using 2-way ANOVA (Analysis of Variance) at 5% level of significance. The natural soil was classified as s A-7-6 and MH under standard soil classification systems. Addition of steel slag lowered the liquid limit (LL) and plasticity index (PI), while cement increased the LL and decreased PI of the lateritic soil, respectively. With increasing content of slag and cement, maximum dry density increased with the corresponding decrease in optimum moisture content. CBR and UCS of the stabilized soil increased substantially with increasing contents of slag and cement. Both steel slag and cement have statistically significant effects on the geotechnical properties of the lateritic soil. Hence, this soil can be stabilized with addition of 12% steel slag and 6% cement contents for its application as an improved subgrade material for light trafficked pavement. Keywords: Lateritic soil, steel slag, cement, stabilization, Index properties, strength indices.

Abstract: Effect of glass fines and cement as a composite mixture on the geotechnical properties of a poor lateritic soil obtained from a borrow pit at Aroje, Ogbomoso, Nigeria was investigated as a reuse method of managing wasted glass. Glass fines up to 12% at intervals of 4% by mass of the soil sample were added to the lateritic soil stabilized with cement of 0, 2, 4, and 6% by mass of the soil sample. Sieve analysis, Atterberg limit, British Standard (BS) Compaction, California Bearing Ratio (CBR) and Unconfined Compressive Strength (UCS) tests were conducted on the stabilized soil specimens. Results showed that Liquid Limit (LL), Plastic Limit (PL) and Plasticity Index (PI) decreased while compaction and UCS of the lateritic soil increased from 0 to 8% addition of glass fines. The CBR of the soil increased continuously from 0 to 12% glass contents. However, addition of cement increased the LL and PI while it decreased the PL between 0 and 4% but increased beyond this range. The compaction, UCS and CBR of the stabilized soil increased significantly with increasing cement content. Hence, the soil can be stabilized with the addition of 8% glass fines and 6% cement content to be used as improved subgrade material for construction of light trafficked pavement.

Abstract: This paper presents the relationship between the dynamic cone penetration (DCP) test results and the unconfined compressive strength of lateritic cemented soils. A series of DCP tests and unconfined compressive strength was performed on lateritic cemented soil. The soils sample used in this study was lateritic soil. The test results for the DCP tests are presented in terms of penetration index. It can be observed that the penetration index decreased with increasing curing period and cement content. Moreover, the unconfined compressive strength of cemented soils increased with curing period and cement content. The relationship between unconfined compressive strength and penetration index is presented. A unique relationship for unconfined compressive strength can be obtained.

Abstract: Ceramic materials are used worldwide due to offer important technical and economic advantages. The ceramic industry, however, has to deal with production losses that are wasted, such as the residue of polishing porcelain tiles. This paper presents the results of laboratory tests performed using different proportions of a lateritic soil and residue of polishing porcelain tile, in order to verify the possibility to use them for highway applications. The main focus of this paper is to propose the optimum ratio of soil and residue based on statistical analysis of the results of unconfined compression tests. Grain size distribution test, X-ray fluoresce analysis and compaction tests were also conducted. An analysis of the data indicates that the addition of residue increases the unconfined compression strength, in comparison to specimens with pure soil. A statistical analysis of the data showed that the best proportion is approximately 92% of soil and 8% of residue.

Abstract: A dark reddish-brown lateritic soil collected from existing borrow pit abandoned by Reynold Construction Company Ltd behind New WAZOBIA Market on Latitude 08008′N and Longitude 04014′E along Ogbomoso-Ilorin Express road, Ogbomoso, Oyo State. Nigeria was treated with cement kiln dust (CKD), a by-product of long wet kiln, obtained from West African Portland Cement Organisation (WAPCO), Ewekoro, Ogun State, Nigeria, under varying moulding water content.The results show gradual reduction in the plasticity index of the samples, decrease in the maximum dry densities (MDD) with corresponding increase in the optimum moisture contents (OMC) of the treated soil samples. The unconfined compressive strength (UCS) of the treated samples increases with both increase in the treatment content as well as compactive effort from British Standard (BS) to West African Standard (WAS) however, there was reduction in the UCS with varying moulding water content as the water content increases and decreases relative to optimum moisture content. The maximum UCS was obtained at optimum moisture content.Cement kiln dust though regarded as waste can therefore serve as potential material in the stabilization of the lateritic soil when compacted at moisture content within its OMC.

Abstract: Great areas of Brazil present lateritic soils, such as the northeast and the south. Some of these soils have, as main characteristic, instable structures that can present considerable volumetric deformation in the presence of water. This behavior, also named collapse, is responsible for several problems on the building construction such as cracks and fractures that can damage the safety of structures. The aim of this paper is to assess the possibility of improvement of collapsible behavior of a lateritic soil using rice husk ash (RHA). A previous characterization of soil and RHA was performed in order to assess the combined effect of soil/RHA. The results are so promising, showing a new alternative to reduce the collapsible behavior of soils using an environmental friendly technology.

Abstract: Lateritic soil treated with up to 20% glass cullet content was subjected to grain-size distribution, consistency tests, specific gravity tests, compaction using standard proctor, California Bearing Ratio (CBR), unconfined compression test, direct shear test and permeability tests. The study showed increase in grain sizes resulting in coarser soil, changes in moisture-density relationship, resulting in lower Optimum Moisture Content (OMC) and higher Maximum Dry Density (MDD), an increase in CBR, an increase in unconfined compressive strength (UCS); changes in cohesion-frictional angle relationship resulting in lower cohesion (c) and higher angle of internal friction (Φ) and an increase in co-efficient of permeability, k, with increased glass cullet treatment. These results show an improvement in geotechnical properties, making glass cullet-lateritic soil blend; a potentially good highway material and suggesting the suitability of the blend for embankments, structural and non-structural fill and retaining wall backfill.