scholarly journals Effect of Silica Fume on the Shear Strength of Cohesionless Soil

2021 ◽  
Vol 18 (1) ◽  
pp. 1-11
Author(s):  
Mahmoud Abo Bakr El Sideek
Keyword(s):  
Shear Strength ◽  
Silica Fume ◽  
Cohesionless Soil

scholarly journals Comparative Study between Silica Fume and Nano Silica Fume in Improving the Shear Strength and Collapsibility of Highly Gypseous Soil

2020 ◽  
Vol 27 (1) ◽  
pp. 72-78
Author(s):  
Ahmed Al-Obaidi ◽  
Marwa Al-Mukhtar ◽  
Omar Al-Dikhil ◽  
Saeed Hannona
Keyword(s):  
Shear Strength ◽  
Silica Fume ◽  
Friction Angle ◽  
Engineering Properties ◽  
Nano Silica ◽  
Direct Shear Tests ◽  
Apparent Cohesion ◽  
Gypsum Content ◽  
Wet Condition ◽  
Gypseous Soil

Soils with highly gypsum content signify known as soils that exhibit collapsibility and sudden failure when being submerged to wetting. Many of the constructions built on this soil showed cracked and/or collapsed at some parts as these soils immersed or leached with water. The utilization of extremely fine materials, for example, Microscale or Nanoscale, is generally utilized these days. This research compared the use of Silica fume (SF) (micro material) and Nano Silica fume (NSF) (Nanomaterial) to explore the capability of these very fine materials to mend the shear strength and collapsibility properties of highly gypseous soils. The soil as Poorly Graded Sand (SP) was used, with a gypsum amount equal to 62%. A succession of direct shear tests and double odometer tests were carried on dry and submarined specimens of soil at various percentages of SF and NSF. The obtained results indicate that mixing the highly gypseous soils with SF or NSF improved the engineering properties of these soils, especially for the wet condition. The average increment in apparent cohesion when adding SF (5-20) percentage varies between (140-310) % in dry soil and (20-40) % in soaked soil. Same results obtained when mixing the gypseous soils with (1-5) % of NSF. Also, the Nanomaterial provided an improvement of the friction angle in dry and submerged cases respectively. Considering that, the SF gives adverse results upon the friction angle of the soil. The SF and the NSF both condensed the dangers of gypseous soil collapsibility. Consequently, the use of NSF can be assertively suggested to improve the engineering characteristics of highly gypseous soils when compared with SF, where only mixing of 3% of NSF gives the best results.

Collapsibility and Shear Strength of Gypseous Soil Improved by Nano Silica Fume (NSF)

2020 ◽  
Vol 857 ◽  
pp. 292-301
Author(s):  
Alaa D. Al-Murshedi ◽  
Mahdi O. Karkush ◽  
Hussein H. Karim
Keyword(s):  
Shear Strength ◽  
Silica Fume ◽  
Dry Mass ◽  
Soil Samples ◽  
Nano Silica ◽  
Collapse Potential ◽  
Geotechnical Characteristics ◽  
Before And After ◽  
Problematic Soils ◽  
Gypseous Soil

The problematic soils have complex and irregular behavior such as gypseous soils, which concentrated mainly in the dry and semi-dry regions in the world. In Iraq, the gypseous soils cover about 30 to 35% of its total area in the west desert and extended to the southern parts of Iraq. The gypseous soils experience sudden collapse upon wetting. The present paper focuses on studying the effects of nano silica fume (NSF) on the collapsibility and shear strength of gypseous soil before and after soaking. Also, this study, the influence of NSF on the chemical and physical characteristics of gypseous soil have been investigated. A gypseous soil sample obtained from Al-Najaf Sea has gypsum content of 42%. The gypseous soil samples are mixed with three percentages of nano silica fume (1, 2, and 4) % calculated as ratio of the dry mass of soil to measure their influence on the geotechnical characteristics of soil samples. The collapse potential of gypseous soil is reduced with increasing the content of nano silica fume. Also, increasing the content of NSF and curing time resulted in increasing the shear strength of soil samples.

UNDRAINED SHEAR STRENGTH OF SOFT CLAY MIXED WITH DIFFERENT PERCENTAGES OF LIME AND SILICA FUME

2016 ◽  
Vol 78 (8-5) ◽  
Author(s):  
Muzamir Hasan ◽  
Ali Jamal Alrubaye ◽  
Leong Kah Seng ◽  
Mohammad Syafiq Ideris ◽  
Aminaton Marto
Keyword(s):  
Compressive Strength ◽  
Shear Strength ◽  
Silica Fume ◽  
Unconfined Compressive Strength ◽  
Soft Clay ◽  
Cost Effective ◽  
Dry Density ◽  
Maximum Dry Density ◽  
Unconfined Compression Test ◽  
Coefficient Of Permeability

Soil stabilisation, as a cost-effective and environmentally friendly method, is used in the building of systems like roads, dams, canals and river levels. Chemical stabilisation of soil is carried out by adding binder or by-products like lime and silica fume to the soil thereby modifying the geotechnical performance of the soil. Various researchers have carried out research on the properties of soil, such as its compaction, compressibility, hydraulic conductivity, and strength characteristics. The focus of the study was the determination of the physical properties of the soft clay used and the strength of soft clay (kaolin) mixed with 6 % of silica fume and various percentages (3 %, 5 %, 7 % and 9 %) of lime. Unconfined compression test was carried out on the soft clay and the mixtures of soft clay-lime-silica fume to investigate the effect of lime stabilisation with silica fume additives on the unconfined compressive strength of the mixtures. Based on the results obtained, all soil samples were indicated as soils with medium plasticity. From 0 % to 9 % of lime with 6 % of silica fume, the decreased in the maximum dry density was by 5.92 % and the increased in the optimum moisture content was by 23.5 %. Decreased in the coefficient of permeability of the mixtures occurred when compared to the coefficient of permeability of the soft clay itself. The improvement in shear strength of soft clay mixed with 6 % silica fume and 5 % lime was 29.83 % compared to the shear strength of the soft clay sample. The optimal percentage of lime-silica fume combination was attained at 5.0 % of lime and 6.0 % of silica fume in order to improve the shear strength of soft clay. It can be concluded that lime-silica fume additives improved the unconfined compressive strength of the soft clay.

Cohesionless Soil Fabric and Shear Strength at Low Confining Pressures

2016 ◽  
Author(s):  
Katherine E. Winters ◽  
Oliver-Denzil S. Taylor ◽  
Woodman W. Berry ◽  
Wesley R. Rowland ◽  
Mark D. Antwine
Keyword(s):  
Shear Strength ◽  
Cohesionless Soil ◽  
Soil Fabric ◽  
Confining Pressures

scholarly journals Slant shear strength of hybrid concrete made with old and new parts using reactive and inert waste powders

2018 ◽  
Vol 7 (4) ◽  
pp. 236
Author(s):  
James H. Haido ◽  
Youkhanna Z. Dinkha ◽  
Badorul H. Abu-Bakar
Keyword(s):  
Shear Strength ◽  
Silica Fume ◽  
High Strength Concrete ◽  
Glass Powder ◽  
High Strength ◽  
Waste Glass ◽  
Strength Concrete ◽  
Waste Glass Powder ◽  
Slant Shear ◽  
Glass Powders

Manufactured reactive powders, as a silica fume, are usually used in production of high strength concrete with for retrofitting purposes of concrete structures. The efficiency of inert waste glass powder in hybrid concrete fabrication has not been widely investigated, thus further studies are essentially considered in this area. In the present study, hybrid concrete prisms with size of 10x10x30 cm have been made with old ordinary concrete (OC) and new high strength concrete (HSC). High strength of new concrete part of these prisms is achieved via using of waste glass powder, silica fume and mixture of them. The roughness of interfacial surface between old and new parts of hybrid concrete is improved in various manners with utilizing sand blast, holes and grooves. Performance of these elements has been measured in terms of slant shear strength and mode of failure. The results have been shown that there is a relatively similar strength with using retrofitted concrete made with the used powder which includes silica fume, glass powders, and their mixture, the mixture of both powders, namely, silica fume and waste glass powders is regarded a best choice in the present stud. It is demonstrated also that the grooved interface between old and new concretes induces proper strength equivalent to 89% of control concrete prisms strength.

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