Stabilization of Silty Sand Soil Using Textile Material

The objective of the present study is to develop a biotechnological tool for a new application of silty sand soil as stabilized materials in linear works replacing chemical stabilizer (e.g. cement and lime) by natural cement, formed by precipitated calcium carbonate generated by microorganisms of the Sporosarcina family. For this purpose, it is conducted a chemical and mineralogical characterization and an examination of physical and geotechnical properties, being very important from the engineering standpoint. The results of different tests are presented here. The data show that the effects of bacteria are reducing the soil specific surface and increasing its plasticity. The reason for this result could be the addition of a plastic component to the natural soil, or the result of the more aggregated structure promoted during the treatment. The pore size distribution of the soil changes in an approximate range 3 - 30 µm, where the pore mode tends to disappear. The change in the pore density function is reflected in the mechanical behaviour of the treated soil, which presents typical features of a less dense soil with respect to the natural untreated one. The friction angle of the treated soil is slightly higher, and its compressibility is consistently lower than that of the natural soil. As the bacteria do not seem to produce any cementation effect on the soil skeleton, collapse upon wetting does not seem to be significantly affected by the treatment. On the contrary, comparison of collapse data shows that occurrence and amount of collapse are ruled by the as-compacted dry density. The tests performed seem to suggest that the microbiological technique may be effective to improve the mechanical characteristics of the compacted soil. For that, it is necessary to provide more energy in compacting the treated soil that it will be stabilized, so as to achieve a high initial dry density. From this viewpoint, it seems that higher compaction effort is even more effective than increasing the amount of bacteria introduced to stabilize the soil.

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DESEMPENHO RODOVIÁRIO LABORATORIAL DO RESÍDUO DE MINERAÇÃO DE MANGANÊS DE LICÍNIO DE ALMEIDA - BA QUANDO MISTURADO COM A BRITA 1

Revista Eletrônica de Gestão e Tecnologias Ambientais ◽

10.9771/gesta.v9i1.38452 ◽

2021 ◽

Vol 9 (1) ◽

pp. 99

Author(s):

Glauber Miranda de Carvalho ◽

Hélio Marcos Fernandes Viana ◽

Rubem Xerxes Trindade Rodrigues ◽

João Paulo Freire Rocha ◽

Gilson Rodrigues Junior

Keyword(s):

Statistical Models ◽

Environmental Problem ◽

Intermediate Energy ◽

Silty Sand ◽

Transport Infrastructure ◽

Crushed Stone ◽

Sand Soil ◽

Road Pavement ◽

Road Performance ◽

Pavement Base

O presente trabalho avaliou o comportamento do CBR, na energia intermediária de Proctor, quando são adicionadas porcentagens de 30%, 50% e 75% de brita 1, em massa, ao rejeito de manganês que foi coletado na região do município de Licínio de Almeida. O objetivo foi encontrar uma mistura que atendesse satisfatoriamente aos requisitos do Departamento Nacional de Infraestrutura de Transportes (DNIT) estabelecidos em 2006 para construção de base de pavimentos rodoviários. Os ensaios laboratoriais realizados na energia intermediária de Proctor verificaram a eficiência de cada uma das misturas a partir dos valores de CBR e de sua expansão observados. Com base nos modelos estatísticos desenvolvidos, este trabalho constatou que uma mistura de rejeito de manganês-brita 1, com apenas 39,5% de teor de brita 1, em massa, atende às referidas exigências. A conclusão do trabalho destaca que a adição de um baixo teor de brita 1, em massa, ao rejeito de manganês torna real a possibilidade de obter dois benefícios: combater um problema ambiental e viabilizar de forma altamente qualitativa a construção da base, que é uma das mais importantes camadas do pavimento rodoviário.Palavras-chave: Pavimento; Rejeitos; Manganês; Meio Ambiente LABORATORY ROAD PERFORMANCE OF LICÍNIO DE ALMEIDA (BA) MANGANESE MINING WASTE, WHEN MIXED WITH BRITA 1AbstractThis work aimed to use statistical modeling based on mixtures of materials, type of manganese tailings-crushed stone 1 to find a mixture that satisfactorily met the requirements of the DNIT (National Department of Transport Infrastructure) for the construction of a road pavement base. The crushed stone composed the studied mixtures in the contents of 30%, 50% and 75% by mass. Manganese tailings were classified as silty-sand soil (A-4 from TRB, SM from USCS and NA from MCT); Thus, the CBR behavior was evaluated that takes basis on the efficiency of each of the mixture for the intermediate energy of Proctor. Furthermore, based on developed statistical models, it was found that a mixture of manganese-crushed stone 1, with only 39.5% of gravel content, by mass, it was possible to meet the requirements of the DNIT (2006) for base construction of road pavements. Finally, with the addition of a low content of crushed stone 1, in mass, to the manganese tailings, the possibility of obtaining two benefits is real: to combat an environmental problem and to make possible the construction of the base, which is one of the most important road pavement layers.Keywords: Pavement; Tailings; Manganese; Environment

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Sand and silty-sand soil stabilization using bacterial enzyme–induced calcite precipitation (BEICP)

Canadian Geotechnical Journal ◽

10.1139/cgj-2018-0191 ◽

2019 ◽

Vol 56 (6) ◽

pp. 808-822 ◽

Cited By ~ 15

Author(s):

Tung Hoang ◽

James Alleman ◽

Bora Cetin ◽

Kaoru Ikuma ◽

Sun-Gyu Choi

Keyword(s):

Soil Stabilization ◽

Silty Sand ◽

Bacterial Cells ◽

Soil Permeability ◽

Calcite Precipitation ◽

Sand Soil ◽

Bacterial Enzyme ◽

Stabilized Soil ◽

Soil Mixtures ◽

Enzyme Application

This paper examines the bio-derived stabilization of sand-only or sand-plus-silt soils using an extracted bacterial enzyme application to achieve induced calcite precipitation (ICP). As compared to conventional microbial induced calcite precipitation (MICP) methods, which use intact bacterial cells, this strategy that uses free urease catalysts to secure bacterial enzyme–induced calcite precipitation (BEICP) appears to offer an improved means of bio-stabilizing silty-sand soils as compared to that of MICP processing. Several benefits may possibly be achieved with this BEICP approach, including bio-safety, environmental, and geotechnical improvements. Notably, the BEICP bio-stabilization results presented in this paper demonstrate (i) higher rates of catalytic urease activity, (ii) a wider range of application with sand-plus-silt soil applications bearing low-plasticity properties, and (iii) the ability to retain higher levels of soil permeability after BEICP processing. Comparative BEICP versus MICP results for sand-only systems are presented, along with BEICP-based results for stabilized soil mixtures at 90:10 and 80:20 percentile sand:silt ratios. This BEICP method’s ability to obtain unconfined compressive strength results in excess of 1000 kPa with sand-plus-silt soil mixtures is particularly noteworthy.

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Geotechnical characterization of soils in the northern zone of Brazzaville

World Journal of Advanced Research and Reviews ◽

10.30574/wjarr.2021.12.1.0486 ◽

2021 ◽

Vol 12 (1) ◽

pp. 086-096

Author(s):

Kempena Adolphe ◽

Mbilou G. Urbain ◽

Bissombolo T. dorjeanny ◽

Antonio O. Gonçalves ◽

Boudzoumou Florent

Keyword(s):

Construction Projects ◽

Silty Sand ◽

Experimental Program ◽

Shear Tests ◽

Sand Soil ◽

Strain Behavior ◽

Geotechnical Characterization ◽

Northern Zone

The geotechnical classification of soils by laboratory tests is usually used to determine the class of the soil under study for its subsequent use in construction projects. The interest is certainly well displayed. Indeed, an experimental program has been developed with the aim of studying the soil in the study area. To this end, oedometric and shear tests were carried out on several soil samples in the laboratory. This made it possible to understand the “stress-strain” behavior of these soils. As a result, the presence of a silty sand soil was found that is susceptible to collapse.

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Effect of Soil Types on the Development of Water Levels and Erosion Processes during Overtopping Test

Civil Engineering Journal ◽

10.28991/cej-03091161 ◽

2018 ◽

Vol 4 (10) ◽

pp. 2315 ◽

Cited By ~ 4

Author(s):

Marwan Adil Hassan ◽

Mohd Ashraf Mohamad Ismail

Keyword(s):

Fine Particles ◽

Digital Camera ◽

Coarse Sand ◽

Water Levels ◽

Silty Sand ◽

Erosion Process ◽

Sand Soil ◽

Erosion Processes ◽

Overtopping Failure ◽

Cohesive Materials

The construction of dike materials is an essential parameters in controlling the safety of hydraulic engineering. The dike material is an earthfill material constructed from non-cohesive materials or mixed from cohesive and non-cohesive materials. Overtopping failure can affect the dike stability during water cross above dike crest and could threat people lives and property. It is reduced the matric suctions binds soil particles due to the increasing volumetric water content during the transition of water level from the upstream into downstream slopes. In this paper, two spatial overtopping tests are conducted in Hydraulic Geotechnical laboratories at the Universiti Sains of Malaysia to observe the evolution of horizontal and vertical water levels as well as the development of lateral and vertical erosion processes under constant inflow discharge of 30 L/min. The vertical and horizontal water levels as well as the vertical erosion process are measured using one digital camera installed in front of dike embankment, while the horizontal erosion process was measured using another digital camera installed in front of downstream slope. Two types of coarse sand and very silty sand soils are used to construct dike embankment in small flume channel. The small flume is constructed from transparent PVC material to observe the development of water distributions and erosion processes with sediment box to collect the eroded materials. A pilot channel is cut in dike crest along the side wall of small flume channel to initiate breach channel in the dike crest. The initiation of breach channel is crucial for the evolution breach channel failure in the downstream and upstream slopes. The results show that the vertical and horizontal water levels are distributed faster in coarse sand soil compared with those in the very silty sand soil while the horizontal water levels are distributed faster than vertical water levels for both soils. The permeability of coarse sand increases the velocity of water flow for occupation soil particles and beginning failure in dike crest faster. The presence of fine particles in the very silty sand has reduced the rate of erosion processes inside dike particles in horizontal and vertical directions. The fine particles absorb a large amount of water content and, thus reduce the easiest water infiltration into particles with higher matric suctions. The analyzing of the distributions of water levels and erosion process help to understand the behavior of dike embankment during overtopping failure and increase the maintenance for dikes parts to reduce the potential danger.

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Strength Enhancement of Silty Sand Soil Subgrade of Highway Pavement Using Lime and Fines from Demolished Concrete Wastes

International Journal of Engineering Research in Africa ◽

10.4028/www.scientific.net/jera.36.74 ◽

2018 ◽

Vol 36 ◽

pp. 74-84 ◽

Cited By ~ 2

Author(s):

Gerard Banzibaganye ◽

Emmanuel Twagirimana ◽

G. Senthil Kumaran

Keyword(s):

Shear Strength ◽

Soil Layer ◽

Silty Sand ◽

Sand Soil ◽

Strength Enhancement ◽

Subgrade Soil ◽

The One ◽

Maximum Shear Strength ◽

Strength Improvement ◽

Highway Pavement

The highway pavement quality and lifetime depend on its different layers such as subgrade, sub-base and base courses. It is of great importance for subgrade soil layer to have the excellent properties as it is the one to lower or increase the project cost. This paper discusses the utilization of lime and fines from concrete waste to enhance the strength of silty sand soil. California Bearing Ratio (CBR) and shear strength were evaluated. The content such as 0%, 2%, 4%, 6%, 8% and 10% were used. The CBR and shear strength of soil increased with the increase of lime or concrete content. The optimum lime and concrete content which maximized CBR were 6% and 8% respectively. The shear strength improvement was also noticed. No optimum content from both stabilizers which gave maximum shear strength.

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