scholarly journals Influence of Polypropylene Fibre (PF) Reinforcement on Mechanical Properties of Clay Soil

2020 ◽  
Vol 2020 ◽  
pp. 1-15 ◽  
Author(s):  
Mazahir M. M. Taha ◽  
Cheng Pei Feng ◽  
Sara H. S. Ahmed
Keyword(s):  
Shear Strength ◽  
Hydraulic Conductivity ◽  
Void Ratio ◽  
Clay Soil ◽  
Polypropylene Fibre ◽  
Dry Density ◽  
Maximum Dry Density ◽  
Polypropylene Fibres ◽  
Study Results ◽  
Consolidation Coefficient

This study investigated the effects of polypropylene fibre (PF) reinforcement on the mechanical behaviour of clay soil. Using clay soil and polypropylene fibres from China’s Inner Mongolia and Hebei Provinces, respectively, a series of soil samples with 0%, 1.5%, 2.25%, and 3% PF content by soil weight were subjected to compaction, shear strength, consolidation, California bearing ratio, and microstructure analyses. The study results indicate improved compaction, shear strength, consolidation, and the bearing ratio of the PF-stabilised clay soil. As the PF content increased, its maximum dry density increased and its optimum moisture content decreased; its angle of internal friction increased and its cohesion coefficient decreased; and its void ratio, consolidation coefficient, and hydraulic conductivity all decreased. Comparing the unstabilised (0% PF) and stabilised (3% PF) clay soil, the void ratio, consolidation coefficient, and hydraulic conductivity decreased from 0.96 to 0.93, from 2.52 to 2.34 cm2/s, and from 1.12 to 1.02 cm/s, respectively. The optimum PF content was determined to be 3% by the weight of the soil, as this quantity resulted in the best improvement in soil properties.

scholarly journals Modification of Mechanical Properties of Expansive Soil from North China by Using Rice Husk Ash

Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 2789
Author(s):  
Mazahir M. M. Taha ◽  
Cheng-Pei Feng ◽  
Sara H. S. Ahmed
Keyword(s):  
Hydraulic Conductivity ◽  
Rice Husk ◽  
North China ◽  
Void Ratio ◽  
Rice Husk Ash ◽  
Clay Soil ◽  
Expansive Soils ◽  
Expansive Soil ◽  
Coefficient Of Consolidation ◽  
Consolidation Coefficient

The construction of buildings on expansive soils poses considerable risk of damage or collapse due to soil shrinkage or swelling made likely by the remarkable degree compressibility and weak shear resistance of such soils. In this research, rice husk ash (RHA) was added to expansive soil samples in different quantities of 0%, 4%, 8%, 12%, and 16% by weight of soil to determine their effects on the plasticity index, compaction parameters, consolidation performance, and California bearing ratio (CBR)of clay soil. The results show that the use of RHA increases the effective stress and decreases the void ratio and coefficient of consolidation. Adding 16% RHA resulted in the greatest reduction in the hydraulic conductivity, void ratio, and coefficient of consolidation. The void ratio decreased from 0.96 to 0.93, consolidation coefficient decreased from 2.52 to 2.33 cm2/s, and hydraulic conductivity decreased from 1.12 to 0.80 cm/s. The addition of RHA improved the soil properties and coefficient of consolidation due to the high density and cohesiveness of RHA. The results of this study can be used to provide a suitable basis for the treatment of expansive soil to provide improved conditions for infrastructure construction.

scholarly journals Effect of Sand Percentage on the Compaction Properties and Undrained Shear Strength of Low Plasticity Clay

2021 ◽  
Vol 9 (1) ◽  
pp. 16-20
Author(s):  
Iyad Alkroosh ◽  
Ali Al-Robay ◽  
Prabir Sarker ◽  
Saif Alzabeebee
Keyword(s):  
Shear Strength ◽  
Moisture Content ◽  
Undrained Shear Strength ◽  
Optimum Moisture Content ◽  
Dry Density ◽  
Sand Content ◽  
Compression Tests ◽  
Maximum Dry Density ◽  
Sand Mixture ◽  
Undrained Shear

This paper investigates the influence of sand content on the mechanical behavior of a low plasticity clay that collected from south of Iraq (Sumer town). Samples have been prepared with sand contents of 0%, 10%, 20%, 30%, and 40% of the clay weight. Standard Proctor and unconfined compression tests have been carried out and the optimum moisture content, maximum dry density, and undrained shear strength have been determined. The results show a gradual increasing trend of the maximum dry density with the increase of the sand content up to 30%. The highest dry density reaches 1.90 g/cm3 corresponding to an optimum moisture content of 12%. In addition, this paper shows that the undrained shear strength is inversely proportional to the increase of the percentage of sand. The results of this work provide a useful addition to the literature regarding the behaviour or low plasticity clay-sand mixture.

Shear Strength of BC-Soil Admixed with Lime and Bio-Enzyme

2019 ◽  
Vol 969 ◽  
pp. 327-334
Author(s):  
C. Jairaj ◽  
M.T. Prathap Kumar ◽  
H. Muralidhara
Keyword(s):  
Shear Strength ◽  
Soil Stabilization ◽  
Morphological Changes ◽  
Ground Improvement ◽  
High Strength ◽  
Sem Analysis ◽  
Dry Density ◽  
Test Results ◽  
Maximum Dry Density ◽  
Lime Content

This BC Soil are expansive in nature and are problematic because of low shear strength and high compressibility. Review of literatures have proven that addition of lime imparts high strength with a corresponding reduction in swell of BC soils. In addition, Bio-enzymes have also been found to play a key role as activators in improving the characteristics of clayey soils such as BC soil. Development and use of non-traditional ground improvement techniques such as bio-enzymes in combination with lime for soil stabilization helps to reduce the cost and the detrimental effects on the soil environment. In the present study lime and bio-enzymes were used as soil stabilizing agents. Compaction test results on BC soil admixed with different percent of lime indicated that 3% addition lime gives higher maximum dry density of 17kN/m3 with OMC of 21% compare to other addition of lime percentages. Keeping 3% of lime as optimum lime content(OLC), BC Soil was admixed with different dosages of Bio-enzymes 25ml/m3, 50ml/m3, 100 ml/m3,150ml/m3, and 200ml/m3 along with OLC was tested for compaction and unconfined compressive strength(UCC). Further UCC test was carried out for different curing period of 0, 7, 15, 30, and 60 Days to analyse the long term effect of BC soil admixed with bio-enzymes with and without lime content. Morphological and chemical analysis was done by using XRD and SEM analysis, from all the test results it was found that 3%OLC + 75ml/m3 of bio-enzymes for 7 day of curing gives higher UCC of 450 kPa. From the SEM it was found that better bond between particles found to develop in bio-enzyme+ lime admixed BC soil in comparison with lime alone admixed BC soil. XRD studies indicated morphological changes in crystallinity and structure of stabilized BC soil in comparison to BC soil alone.

scholarly journals MECHANICAL PROPERTIES OF BOTTOM ASH – DREDGED MATERIAL MIXTURES IN LABORATORY TESTS

2013 ◽  
Vol 35 (3) ◽  
pp. 3-11 ◽  
Author(s):  
Lech Bałachowski ◽  
Zbigniew Sikora
Keyword(s):  
Mechanical Properties ◽  
Void Ratio ◽  
Bottom Ash ◽  
Physical And Mechanical Properties ◽  
Friction Angle ◽  
Ash Content ◽  
Dry Density ◽  
Dredged Material ◽  
Maximum Dry Density ◽  
Proctor Test

Abstract Bottom ash from EC Gdańsk and dredged material taken from the mouth of The Vistula were mixed to form an engineering material used for dike construction. Mixtures with different bottom ash content were tested in laboratory to determine its basic physical and mechanical properties. The optimum bottom ash-dredged material mixture, built in the corps of the test dike, contains 70% of ash. The optimum bottom ash content in the mixture was chosen taking into account high internal friction angle, good compaction and reduced filtration coefficient. The maximum dry density of the mixtures was measured in Proctor test for the mixtures formed in laboratory and on samples taken from the test dike. Minimum and maximum void ratio were also determined.

Effect of sand percentage on the compaction properties and undrained shear strength of low plasticity soft clay

2021 ◽  
Author(s):  
Iyad Alkroosh ◽  
◽  
Ali Al-Robay ◽  
Prabir Sarker ◽  
Saif Alzabeebee ◽  
...  
Keyword(s):  
Shear Strength ◽  
Moisture Content ◽  
Soft Clay ◽  
Undrained Shear Strength ◽  
Optimum Moisture Content ◽  
Dry Density ◽  
Sand Content ◽  
Compression Tests ◽  
Maximum Dry Density ◽  
Undrained Shear

This study investigated the influence of sand content on the mechanical behaviour of a low plasticity clay found in Iraq. Samples were prepared with sand contents of 0%, 10%, 20%, 30%, and 40% of the weight of the clay. Standard Proctor and unconfined compression tests were carried out and the optimum moisture content, maximum dry density, and undrained shear strength were determined. The results showed a gradual increasing trend of the maximum dry density with the increase of the sand content up to 30%. The highest dry density reached was 1.90 gm/cm3 corresponding to an optimum moisture content of 12%. In addition, it was also found that the undrained shear strength was inversely proportional to the increase of the percentage of sand. Thus, the dry density of the clay could be increased well above 1.70 g/cm3, which is the minimum dry density accepted as a compacted subgrade according to the Iraqi General Specifications for Roads and Bridges (2003); hence, the rejected low plasticity clay could be utilised by mixing with sand. The reasons for the increase of the dry density and the decrease of the undrained shear strength has been extensively discussed in the paper.

Behavior of a Sandy Silt Reinforced with Discontinuous Recycled Fiber Inclusions

2000 ◽  
Vol 1714 (1) ◽  
pp. 9-17 ◽  
Author(s):  
J. J. Murray ◽  
J. D. Frost ◽  
Y. Wang
Keyword(s):  
Shear Strength ◽  
Axial Strain ◽  
Triaxial Compression ◽  
Value Added ◽  
Strength Loss ◽  
Dry Density ◽  
Compression Tests ◽  
Maximum Dry Density ◽  
Deformation Response ◽  
Sandy Silt

Laboratory compaction and triaxial compression tests were performed to assess the compaction characteristics and load deformation response of a sandy silt reinforced with randomly oriented recycled carpet fibers. Discrete, randomly distributed fiber inclusions significantly increase the peak shear strength, reduce the postpeak strength loss, increase the axial strain to failure, and, in some cases, change the stress-strain behavior from strain softening to strain hardening for a sandy silt. Fiber inclusions also impede the compaction process, causing a reduction in the maximum dry density of reinforced specimens with increasing fiber content. The strength losses associated with in-service saturation are significantly reduced with fiber reinforcement. It is suggested that large volumes of recycled waste fibers can be used as a value-added product to enhance the shear strength and load deformation response of soils.

Predicting the engineering and transport properties of soils using fractal equivalent circuit model: Laboratory experiments

Geophysics ◽  
2011 ◽  
Vol 76 (5) ◽  
pp. F329-F338 ◽  
Author(s):  
Fred Kofi Boadu
Keyword(s):  
Hydraulic Conductivity ◽  
Transport Properties ◽  
Equivalent Circuit ◽  
Void Ratio ◽  
Equivalent Circuit Model ◽  
Circuit Model ◽  
Dry Density ◽  
Electrical Measurements ◽  
Intergranular Void Ratio ◽  
Intergranular Void

Frequency-dependent electrical measurements of soils contain useful information about their texture and structure that can be linked to their engineering and transport properties. We performed frequency-dependent electrical measurements on 29 natural soils with wide variability in physical and textural properties in a laboratory environment at a constant stress level and in the frequency range of 0.01 Hz–10 kHz. The engineering and hydraulic properties of these soils, that is, the hydraulic conductivity [Formula: see text], void ratio [Formula: see text], fines content [Formula: see text], intergranular void ratio [Formula: see text] and the dry density [Formula: see text] are concurrently measured. The electrical behaviors of the soils are modeled with an equivalent circuit model, which are described by six circuit parameters. Relationships between the circuit parameters and the soil properties (geotechnical engineering and hydraulic) are investigated. Crossplots of frequency exponent [Formula: see text] and resistivity [Formula: see text] and that of [Formula: see text] and grain percent resistivity [Formula: see text] clusters soils with high and low values of hydraulic conductivity, whereas crossplots of relaxation time [Formula: see text] and [Formula: see text] clusters soils with high and low intergranular void ratio. Regression models are developed using the parameters [Formula: see text] and [Formula: see text] to predict the hydraulic conductivity with [Formula: see text]; [Formula: see text] and [Formula: see text] to predict the intergranular void ratio with [Formula: see text] and [Formula: see text] and [Formula: see text] to predict the dry density with [Formula: see text].

Effect of Slag on Engineering Properties of Contamination Soil

2020 ◽  
Vol 857 ◽  
pp. 253-258
Author(s):  
Mohamed Moafak Arbili ◽  
Mohamed Karpuzcu ◽  
Farman Khalil
Keyword(s):  
Shear Strength ◽  
Contaminated Soils ◽  
Engineering Properties ◽  
Dry Density ◽  
Maximum Dry Density ◽  
Additional Material ◽  
Pozzolanic Reactivity ◽  
Density Values ◽  
The Impact ◽  
Water Contents

In this study investigates utilizing of slag as an additional material to improve engineering properties of contaminated soil by crude oil to changing the engineering characteristics to be satisfying and compatible, this is due to its pozzolanic reactivity. The aim of this study the impact of slag material in geotechnical engineering and to stabilize properties of contaminated soils. Two percentages of slag were utilized in this study, which is 0% and 6%. Compaction and direct shear strength tests had been conducted on the artificial contaminated prepared soil samples. In the results, showed that the increasing of slag leads to a decrease in the optimum water contents while the maximum dry density values increase. Furthermore, the shear strength is improved by utilizing slag so that slag can be considered as a stabilizing material to improve the properties of contamination soil.

Application of Genetic Programming for Estimation of Soil Compaction Parameters

2011 ◽  
Vol 147 ◽  
pp. 70-74 ◽  
Author(s):  
Navid Naderi ◽  
Pedram Roshani ◽  
Masoud Zabihi Samani ◽  
Mohammad Amin Tutunchian
Keyword(s):  
Genetic Programming ◽  
Numerical Models ◽  
Soil Classification ◽  
Dry Density ◽  
Maximum Dry Density ◽  
Model Study ◽  
Linear Behavior ◽  
Soft Computing Method ◽  
Study Results ◽  
Input Variables

The aim of this study is to propose two numerical models by a well-known soft computing method, Genetic Programming (GP), for the estimation of soils compaction parameters. Genetic Programming is a pattern recognition approach that has the ability of modeling the non-linear behavior of complex engineering problems. The input variables were the soil classification properties, and the outputs were the Optimum Moisture Content (OMC) and Maximum Dry Density (MDD). To provide model, a database including properties of different soils classified as CH, CI, CL, GC, GM, MH, MI, ML and SC was used. In addition, a new Multiple Linear Regression (MLR) based formula using the database, compared with the GP based model. Study results revealed that the proposed formula by GP can predict the compaction parameters of soils in a highly precise manner, and its outputs were in satisfactory conformity with real test results. Performances of the proposed models evaluated using the regression statistical analyses. The proposed formulae can be useful for the preliminary design of engineering projects and are more useful for cases with time and financial limitations.

scholarly journals Experimental Study on Unconfined Compressive Strength of Basalt Fiber Reinforced Clay Soil

2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Lei Gao ◽  
Guohui Hu ◽  
Nan Xu ◽  
Junyi Fu ◽  
Chao Xiang ◽  
...  
Keyword(s):  
Compressive Strength ◽  
Unconfined Compressive Strength ◽  
Clay Soil ◽  
Soil Column ◽  
Basalt Fiber ◽  
Dry Density ◽  
Fiber Reinforced ◽  
Maximum Dry Density ◽  
Sem Images ◽  
Reinforced Clay

In order to study the mechanism and effect of basalt fiber reinforced clay soil, a series of unconfined compressive strength tests conducted on clay soil reinforced with basalt fiber have been performed under the condition of optimum water content and maximum dry density. Both the content and length of basalt fiber are considered in this paper. When the effect of content is studied, the 12 mm long fibers are dispersed into clay soil at different contents of 0.05%, 0.1%, 0.15%, 0.20%, 0.25%, 0.30%, and 0.35%. When the effect of length is researched, different lengths of basalt fibers with 4 mm, 8 mm, 12 mm, and 15 mm are put into soil at the same content of 0.05%. Experimental results show that basalt fiber can effectively improve the UCS of clay soil. And the best content and length are 0.25% and 12 mm, respectively. The results also show that the basalt fiber reinforced clay soil has the “poststrong” characteristic. About the reinforcement mechanism, the fiber and soil column-net model is proposed in this paper. Based on this model and SEM images, the effect of fiber content and length is related to the change of fiber-soil column and formation of effective fiber-soil net.

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