Lime Stabilization of Black Cotton Soil Using Bagasse Ash as Admixture
TL;DR: In this paper, the effect of bagasse ash (BA) admixture on the engineering properties of lime treated black cotton soil was carried out and the results obtained show that the moisture density relationship follows a trend of increasing optimum moisture content (OMC)/decreasing maximum dry density (MDD) at the Standard Proctor compaction energy.
Abstract: Laboratory studies to investigate the effect of Bagasse Ash (BA) admixture on the engineering properties of lime treated black cotton soil was carried out. Black cotton soil is classified as A-7-6 or CH respectively. Bagasse ash is obtained from burning the fibrous residue from the extraction of sugar juice from sugarcane. The results obtained show that the moisture density relationship follows a trend of increasing optimum moisture content (OMC)/decreasing maximum dry density (MDD) at the Standard Proctor compaction energy. California bearing ratio (CBR) values obtained are lower than the 80% CBR criterion for untreated base course materials. The peak CBR value obtained was 31% at 8 %lime/ 4%BA. This value meets the recommended criteria for subgrade materials. The Unconfined compressive strength (UCS) at 7 days is lower than the 1034.25kN/m2 evaluation criterion for adequate lime stabilization. On the basis of the soaked CBR and durability values, it is recommended that black cotton soil can be stabilized for road construction using a 8 % lime/ 4 % BA blend of admixture at standard proctor compaction. However, due to the relative high cost of lime and large quantity that shall be required to achieve stabilization, further study and consideration should therefore be given to the use another additive such as cement to augment and lower the percentage of lime and thus the cost of stabilization.
Citations
More filters
TL;DR: In this paper, the state of the practice in stabilization techniques and challenges is presented with a discussion, and available studies regarding the effects of various types of stabilizing agents on the engineering and geotechnical properties of stabilized soils are reviewed.
Abstract: Soil stabilization is a technique to improve the engineering and geotechnical properties of soils such as mechanical strength, permeability, compressibility, durability and plasticity. Much has been learned about soil stabilization techniques and additives over the past century. The state of the practice in stabilization techniques and challenges is presented with a discussion. Moreover, available studies regarding the effects of various types of stabilizing agents on the engineering and geotechnical properties of stabilized soils are reviewed here. These stabilizing agents include both calcium-based and non-calcium-based additives. Eco-friendly additives as alternative materials to conventional stabilizing agents are also discussed in this paper. In addition, the problems associated with the presence of disruptive salts and sulfate as well as the techniques to overcome these problems in soil stabilization projects are reviewed.
187 citations
TL;DR: In this paper, the additive and techniques applied for stabilizing expansive soils will be focused on, with respect to their efficiency in improving the engineering properties of the soils, and some issues regarding the effective application of the emerging trends in expansive soil stabilisation were presented with three categories, namely geoenvironmental, standardisation and optimisation issues.
Abstract: Expansive soils are problematic due to the performances of their clay mineral constituent, which makes them exhibit the shrink-swell characteristics. The shrink-swell behaviours make expansive soils inappropriate for direct engineering application in their natural form. In an attempt to make them more feasible for construction purposes, numerous materials and techniques have been used to stabilise the soil. In this study, the additives and techniques applied for stabilising expansive soils will be focused on, with respect to their efficiency in improving the engineering properties of the soils. Then we discussed the microstructural interaction, chemical process, economic implication, nanotechnology application, as well as waste reuse and sustainability. Some issues regarding the effective application of the emerging trends in expansive soil stabilisation were presented with three categories, namely geoenvironmental, standardisation and optimisation issues. Techniques like predictive modelling and exploring methods such as reliability-based design optimisation, response surface methodology, dimensional analysis, and artificial intelligence technology were also proposed in order to ensure that expansive soil stabilisation is efficient.
171 citations
TL;DR: In this article, the authors proposed a methodology to determine the required optimal lime dosage based on scientific criteria, by incorporating the influence of soil properties such as clay mineralogy, specific surface area, soil pH, cation exchange capacity, soil acidity, base saturation capacity, and buffer capacity.
Abstract: The stabilization of problematic fine-grained soils using lime as an admixture is a widely accepted practice, owing to its simplicity and cost-effectiveness. The optimal quantity of lime required for soil stabilization primarily depends upon the reactive nature of soil as well as the degree of improvement desired. The term ‘optimum lime content’ (OLC) defines the amount of lime required for satisfying the immediate/short-term soil–lime interaction, and still providing sufficient amount of free calcium and high residual pH necessary to initiate long-term pozzolanic reaction. Previous researchers proposed various empirical correlations and experimental methodologies for determining OLC, in terms of clay-size fraction and plasticity characteristics of virgin soil. However, the limiting lime content obtained using various conventional methods does not account for the most influencing inherent clay mineralogy of the soil; and hence, the results of these methodologies are observed to be quite disagreeing with each other. In view of these discrepancies, the present study attempts to validate the existing conventional methodologies for OLC determination at an elementary level, by comprehending the fundamental chemistry following soil–lime interactions. Based on the theoretical and experimental observations, it is quite evident that the accuracy of conventional tests is limited by combined influence of chemical and mineralogical properties of soils. Hence, it is proposed to develop a precise methodology to ascertain the required optimal lime dosage based on scientific criteria, by incorporating the influence of soil properties such as clay mineralogy, specific surface area, soil pH, cation exchange capacity, soil acidity, base saturation capacity, and buffer capacity.
62 citations
TL;DR: In this article, fly ash geopolymer was used to improve the engineering properties of black cotton soil (BCS) by stabilizing it with fly ash geo-polymer.
Abstract: It has always been a challenge for civil engineers to lay roads in the areas covered by expansive soil. The expansive soil undergoes extreme phase changes from being hard in hot summer to being slushy and without strength in monsoon season. Thus, the engineering properties of the expansive soil must be improved before laying the roads. This paper presents the results of experimental work carried out to improve the engineering properties of an expansive clay i.e. black cotton soil (BCS) by using fly ash geopolymer. Sodium hydroxide (NaOH) and sodium silicate (Na2SiO3) solutions were mixed in different ratios (0.5, 1, 1.5, and 2) and used for synthesizing the geopolymer. The stabilized BCS samples were characterized in the laboratory for various properties viz., Atterberg’s limits, free swell ratio, and unconfined compressive strength. The untreated and treated BCS samples were also analyzed for their microstructural and morphological properties by using the SEM (scanning electron microscope) images and the XRD (X-ray fiffractometer) and FTIR (Fourier-transform infrared spectroscopy) spectra. An increase in the unconfined compressive strength and reduction in free swell ratio as well as shrinkage limit was observed after stabilization with geopolymer. Results also indicate binding of soil particles and formation of dense microstructure resulting in higher strength and less swelling and shrinkage characteristics. Furthermore, the bender element test was used to indicate the improvement in stiffness of the geopolymer stabilized expansive soil in terms of shear wave velocity.
54 citations
TL;DR: In this article, the authors used four compaction energies (i.e., reduced Proctor, standard, intermediate and modified Proctor) at −2, 0, 2 and 4% molding water content of the optimum moisture content (OMC).
Abstract: Laboratory tests were conducted on a reddish-brown lateritic soil treated with up to 12 % bagasse ash to assess its suitability in waste containment barriers applications. Soil samples were prepared using four compaction energies (i.e. reduced Proctor, standard Proctor, West African Standard or ‘intermediate’ and modified Proctor) at −2, 0, 2 and 4 % moulding water content of the optimum moisture content (OMC). Index properties, hydraulic conductivity (k), volumetric shrinkage and unconfined compressive strength (UCS) tests were performed. Overall acceptable zones under which the material is suitable as a barrier material were obtained. Results recorded showed improved index properties; hydraulic conductivity and UCS with bagasse ash treatment up to 8 % at the OMC. Volumetric shrinkage strain increased with higher bagasse ash treatment. Based on the overall acceptable zone obtained, an 8 % optimal bagasse ash treatment of the natural lateritic soil makes it suitable for use in waste containment barrier application.
46 citations
References
More filters
Journal Article•
TL;DR: For example, this article found that when they are dry, expansive soils are hard and strong, often badly cracking structures built on them, and walls may not be heavy enough to resist soil swelling (uplifting).
Abstract: Each year, shrinking or swelling soils inflict at least $2.3 billion in damages to houses, buildings, roads, and pipelines-- more than twice the damage from floods, hurricanes, tornadoes, and earthquakes. Yet Washington continues to spend billions of dollars for flood control, but almost nothing to lessen damages from swelling soils. When they are dry, expansive soils are hard and strong, often badly cracking structures built on them. While expansion is more of a problem in arid and semi-arid areas, shrinkage caused by dessication can affect structures in areas with sizeable precipitation. Over 250,000 new homes are built on expansive soils each year; 10% of these will experience severe damage during their lifetime. Expansive soils also damage multi-story buildings. Walls may not be heavy enough to resist soil swelling (uplifting). The same walls are most vulnerable if supporting soil dries out and shrinks, removing wall support.
260 citations
Additional excerpts
...hazard including earthquakes and floods [8]....
[...]
01 Jan 2009
TL;DR: In this paper, the effect of up to 12% bagasse ash by weight of dry soil on the geotechnical properties of the deficient lateritic soil was investigated using particle size analysis, compaction, unconfined compressive strength (UCS), California bearing ratio, and durability tests.
Abstract: A lateritic soil was treated with an agro-industrial waste product of sugar mills — Bagasse Ash The study focused on the effect of up to 12% bagasse ash by weight of dry soil on the geotechnical properties of the deficient lateritic soil Test specimens were subjected to particle size analysis, compaction, unconfined compressive strength (UCS), California bearing ratio (CBR) and durability tests The compactions were carried out at the energy of the British Standard Light (BSL)
69 citations
"Lime Stabilization of Black Cotton ..." refers background in this paper
...3 shows the variation of maximum dry density (MDD) of lime treated black cotton soil with bagasse ash....
[...]
...Although, the lime treated black cotton soil admixed with bagasse ash do not meet the minimum criteria as specified [2] for materials suitable for use as base course material of not less than 30% C.B.R determined at MDD and OMC, the treated material can be used as a suitable sugrade material, hence it attains a CBR value of 20 % as against the 15 % requirement criterion [2]....
[...]
...The MDD of the untreated black cotton soil was 1.40 Mg/m3....
[...]
...The decrease in MDD with addition of lime is probably due to the presence of larger quantities of lime with lower specific gravity occupying larger spaces within the soil lattice thereby decreasing the MDD [7, 25, 26]....
[...]
...Early increases in MDD values observed between 2 % and 4 % bagasse ash content could be attributed to ion exchange at the surface of clay particles as the Ca2+ in the stabilizer reacted with the lower valence metallic ions in the clay microstructure which resulted in agglomeration and flocculation of the clay particles....
[...]
TL;DR: In this paper, a brief review of the geology of the black cotton soils of northeastern Nigeria has been given, showing that the soils are predominantly kaolinite and montmorillonite, and that a mixture of both lime and cement is necessary for adequate stabilization of road bases for heavy wheel loads.
60 citations
"Lime Stabilization of Black Cotton ..." refers background in this paper
...3 shows the variation of maximum dry density (MDD) of lime treated black cotton soil with bagasse ash....
[...]
...Although, the lime treated black cotton soil admixed with bagasse ash do not meet the minimum criteria as specified [2] for materials suitable for use as base course material of not less than 30% C.B.R determined at MDD and OMC, the treated material can be used as a suitable sugrade material, hence it attains a CBR value of 20 % as against the 15 % requirement criterion [2]....
[...]
...The MDD of the untreated black cotton soil was 1.40 Mg/m3....
[...]
...The decrease in MDD with addition of lime is probably due to the presence of larger quantities of lime with lower specific gravity occupying larger spaces within the soil lattice thereby decreasing the MDD [7, 25, 26]....
[...]
...Early increases in MDD values observed between 2 % and 4 % bagasse ash content could be attributed to ion exchange at the surface of clay particles as the Ca2+ in the stabilizer reacted with the lower valence metallic ions in the clay microstructure which resulted in agglomeration and flocculation of the clay particles....
[...]
Journal Article•
TL;DR: In this paper, the effect of the type and content of the clay fraction on the specimens' compressive strength, Q, cohesion, C, angle of internal friction, phi, and elastic modulus, e, was determined.
Abstract: Artificially prepared, lime-treated mixtures of sand-clay were studied in the laboratory. The experimental programme was arranged with two types of clay mineral (kaolinite and montmorillonite), three levels of clay content (10,30 and 50 per cent), four levels of lime content for the kaolinite soils (0,2,4,8 per cent) and five levels for the montmorillonite soils (0,2,4,8,12 per cent). Two periods of curing (seven and 28 days) were employed. Firstly the maximum dry density optimum moisture content relationships for the 27 different mixtures were determined using one compactive effort. Test specimens for these mixtures were then fabricated at their corresponding optimum compaction conditions. The effect of the type and content of the clay fraction on the specimens' compressive strength, Q, cohesion, C, angle of internal friction, phi, and elastic modulus, e, was determined. The results showed that regardless of the clay content in the soil, increases in the values of q, C, and e due to lime-treatment are significantly higher for the montmorillonite than for the kaolinite specimens. Generally the most significant increase in any of these parameters occurs at two per cent lime for the kaolinite specimens, while for the montmorillonite specimens these strength parameters tend to develop progressively with lime content up to about eight per cent or even beyond. The pattern of increase in the angle of internal friction due to lime treatment is comparable for the two types of soil. The most significant increase occurs mostly up to two per cent lime where it reaches about 10 degrees. Good correlations between unconfined compressive strength and both cohesion and elastic modulus were observed. Linear regression equations for the prediction of and e for lime-treated soils from known values of g were accordingly established. (Author/TRRL)
53 citations
24 Jan 2008
TL;DR: In this paper, the effect of three compactive efforts (i.e., British Standard Light, BSL, West African Standard, WAS and British Standard Heavy, BSH) on the strength properties of treated black cotton soil was analyzed.
Abstract: The paper presents the results of a laboratory study on the influence of three compactive efforts, (i.e., British Standard Light, BSL, West African Standard, WAS and British Standard Heavy, BSH) on the strength properties of treated black cotton soil. The tropical black clay was treated with a maximum 10% bagasse ash by weight of dry soil and the results show that the strength properties of the soil-bagasse ash mixture increased with higher compactive effort. The maximum dry densities (MDD) of the natural soil for BSL, WAS and BSH compactive efforts are 1.75, 1.91 and 2.05 Mg/m 3 , respectively. Treatment of natural soil with stabilizer gave peak values of 1.83 Mg/m 3 at 10 % bagasse ash for BSL, 1.9 Mg/m 3 at 8% bagasse ash for WAS, and 2.1 Mg/m 3 at 2% bagasse ash for BSH compactive energy. The unconfined compressive strength (UCS) for the natural soil for the BSL, WAS, and BSH compactive efforts are 120, 355, and 424 kN/ m 2 , respectively, while the treated soil gave peak values of 229 kN/m 2 at 10% bagasse ash for BSL, 469 kN/m 2 at 6% bagasse ash for WAS and 756 kN/m 2 at 8% bagasse for BSH compactive effort. Peak California bearing ratio (CBR) values for the BSL, WAS, and BSH compactive energies for the natural soil are 3, 6 and 8%, respectively, while values for treated soil are 8 at 10% bagasse ash for BSL, 11% at 2% bagasse ash for WAS and 13% at 8% bagasse ash for the BSH compactive effort. The WAS compaction energy which is conventionally used in the region yielded CBR value of 11% at 2% bagasse ash treatment of soil is recommended for use as subgrade of lightly trafficked roads in view of expected increase in strength due to time-dependent pozzolanic reactions. Keywords : California bearing ratio, Compactive effort, Unconfined compressive strength, British Standard Light, West African Standard, British Standard Heavy, Maximum dry density and Optimum moisture content. Nigerian Journal of Soil and Environmental Research Vol. 7 2007: pp. 92-101
28 citations
"Lime Stabilization of Black Cotton ..." refers background in this paper
...This reaction increased the affinity for H+ that caused a reduction in UCS to a minimum value of 114 kN/m2, less than the MDD of the unstabilized soil sample....
[...]
...It was observed that as the lime content increased, the MDD decreased....
[...]
...The MDD decreased on addition of lime to a value of 1.41 Mg/m3 at 2% lime content....
[...]
...3 shows the variation of maximum dry density (MDD) of lime treated black cotton soil with bagasse ash....
[...]
...Although, the lime treated black cotton soil admixed with bagasse ash do not meet the minimum criteria as specified [2] for materials suitable for use as base course material of not less than 30% C.B.R determined at MDD and OMC, the treated material can be used as a suitable sugrade material, hence it attains a CBR value of 20 % as against the 15 % requirement criterion [2]....
[...]