study on strength behavior of organic soil stabilized with...

Research ArticleStudy on Strength Behavior of Organic Soil Stabilizedwith Fly Ash

Bayshakhi Deb Nath Md Keramat Ali Molla and Grytan Sarkar

Department of Civil Engineering Khulna University of Engineering amp Technology Khulna 9203 Bangladesh

Correspondence should be addressed to Bayshakhi Deb Nath bayshakhidebnathyahoocom

Received 5 May 2017 Accepted 9 August 2017 Published 11 September 2017

Academic Editor Robert Cerny

Copyright copy 2017 Bayshakhi Deb Nath et al This is an open access article distributed under the Creative Commons AttributionLicense which permits unrestricted use distribution and reproduction in any medium provided the original work is properlycited

The aim of this study is to investigate the effect of fly ash on the consistency compactness acidic properties and strength of organicsoilThe presence of organic content in the soil has detrimental impacts on the physical and strength behavior of soil To investigatethe effectiveness of fly ash in the stabilization of organic soil two types of fly ashes (Type I and Type II) at different percentageswere used It is found that fly ash significantly reduces the plasticity index of the organic soil whereas the liquid and plastic limitsincreaseThe dry density of the fly ash-soil mixture increases significantly while the water requirement reduces due to the additionof fly ashThe increase of dry density compromises higher strengthThe increase of 119902119906 with the increase of fly ash content is mainlydue to the pozzolanic reaction of fly ash although the reduction in water content results from the addition of dry fly ash solidMoreover Type I fly ash contributes a higher value of qu compared to Type II fly ash This is attributed to the characteristics of flyash including CaO and CaOSiO2 ratio

1 Introduction

Soil is one of the most important and primary media forany construction work The strength and durability of anystructure depends on the strength properties of soil It hasbeen found from several studies that due to the detrimentalcharacteristics of organic soil the shear strength and bearingcapacity of this soil are very low while the compressibility isvery high In recent years subgrades of roadways are gen-erally constructed by replacing the underneath organic soilwith granular soil named ldquocut and replacerdquo or preloading toimprove the engineering properties of soil which requires ahuge investment cost and effort This cost of using granularsoil can be minimized by blending and mixing the existingsoil with a cementing admixture known as chemical stabi-lization processThe processmay include the blending of soilsto achieve a desired gradation or the mixing of commerciallyavailable additives which may alter the gradation or themixing of commercially available additives that may alterthe gradation texture or plasticity or act as a binder forthe cementation of soil [1] Cementing admixtures includingcement lime rice husk ash and fly ash are widely used and

have attracted the attention of researchers because of their lowcost and high pozzolanic action [2ndash7]

Fly ash is the combustion product of subbituminous coalin electric power plants and requires to be landfilled How-ever many countries have promoted the reuse of thesetypes of wastes in the interest of sustainable constructionTherefore the use of fly ash as a binding admixture not onlyimproves the engineering properties of soil but also reducesthe use of energy and greenhouse gases Fly ash disperses thesoil cement clusters into smaller clusters thereby increasingthe reactive surface for hydration and pozzolanic reactions [89] Due to these pozzolanic characteristics the shear strengthand bearing capacity of the organic soil can be increased bystabilizing it with fly ash Fly ash reduces the plasticity indexand shrinkage limit which has a potential impact on theengineering properties of fine-grained soil [10 11] Howeverthe effectiveness of the stabilization depends on the organiccontent present in the soil which is not taken into account inthe case of inorganic soil [12ndash16]

Khulna is the third largest metropolitan and second portcity in Bangladesh which is located at the southwesternregion of the country bounded by the latitude from 22∘461015840010158401015840

HindawiInternational Scholarly Research NoticesVolume 2017 Article ID 5786541 6 pageshttpsdoiorg10115520175786541

2 International Scholarly Research Notices

Table 1 Index properties of soil

Property name ValuesUnit weight (kNm3) 1117Liquid limit 119908119871 () 852Plastic limit 119908119875 () 6253Plasticity index 119868119901 () 2267Shrinkage limit 119908119904 () 2819Shrinkage ratio SR 124Water content w () 8712Specific gravity 119866119904 219pH 637Organic content () 369Classification

USCS OHAASHTO

to 22∘581015840010158401015840 north and longitude 89∘281015840010158401015840 to 89∘371015840010158401015840 east Itis a linear shaped city with an elevation from 9m in the northto 2m towards the southwest direction from the mean sealevel comprising very soft to soft consistency up to 20 ft fromthe ground surface levelThe generalized investigation resultsshowed that the soils in the northern and southern part aremainly composed of clay with silt and organic deposits themiddle eastern part comprises sand with some clay and amoderate type of soil is found in the middle western partwhich includes mainly silt with clay and sand It has beenfound that the organic soil exists here at a depth of 10 to25 ft below the existing ground surface and the organiccontent of this soil ranges from 5 to 70 and even morein some instances It is seen that most of the region of thisarea contains fine-grained soil with some organic depositswhich have lower bearing capacity and are not good forshallow foundations for buildings and roadways HoweverKhulna City is progressing with several development projectsincluding construction of high-rise buildings oil storagetanks long span bridges harbors port structures floodprotection embankments and barrages Since all structuralloads are transferred to soil the characteristics of soil playa vital role in the safety of these structures [17] In thisstudy the effectiveness of fly ash on the strength and densityof the organic soil of Khulna region was investigated Inaddition the quantity of fly ash that optimizes the unconfinedcompressive strength of stabilized organic soil was also esti-mated at different curing days

2 Materials and Methods

21 Soils The soft organic soil having organic content of369 was collected from Beel Dakatia Shiromoni KhulnaSamples were collected within a depth of about 15m from theexisting ground surface The collected soil was kept in a largepolythene bag and dried in air for about 7 days Table 1 showsthe physical and index properties of the organic soil ASTMD2974-14 [18] It is seen that the soil contains high liquid limitlow unit weight and high water content

Table 2 Chemical composition and physical properties of fly ash

Composition or property Type I Type IIChemical composition

Silica (SiO2) 502 656Alumina (Al2O3) 225 25Iron oxide (Fe2O3) 517 6Lime (CaO) 203 178Sulphates (SO3) 039 03Magnesia (MgO) 051 07

Physical propertiesFineness (specific surface) by Blainersquos 3746 300permeability method (m2kg)Sieving on 45-micron residue () 1782 705Loss on ignition () 402 400Insoluble residue () 9074 9600Moisture () 018 2

22 Fly Ashes Fly ash is a very fine powdery material com-posed mostly of silica which is a product of burning finelyground coal in a boiler to produce electricity Two types of flyash were collected from locally available cement industries inthe southern part of Khulna The chemical composition andphysical composition of Type I and Type II are summarizedin Table 2 According to ASTMC 618 Type I fly ashes classifyas Class C ash and Type II fly ashes classify as Class F [19 20]It is found that Class C fly ashes are finer compared to ClassF fly ashes while the other physical properties remained thesame Moreover the CaO and CaOSiO2 content of Class Ffly ashes is lower than that of the Class C fly ashes ThereforeClass C fly ashes offer a more economical alternative as a soilstabilizing agent because of their pozzolanic characteristicsThis type of fly ash provides the opportunity for applicationswhere other activators would not be required [21]

23 Experimental Method Standard Proctor compactiontests were carried out to determine the optimum moisturecontent and maximum dry density of all fly ash-soil mixturesaccording to ASTM D698-12e2 [22] Cylindrical sampleshaving a diameter of 38mm and height of 76mm used in theUCS test were prepared at their corresponding optimummoisture content and maximum dry density by static com-paction For curing the samples were closely wrapped in apolythene bag and placed above water in a desiccator kept ina roomThe unconfined compressive strength of the sampleswas assessed according to ASTM D5102-09 [23] The indexproperties of the organic soil and fly ash treated soil weredetermined according to ASTM D2976-15 [24]

3 Results and Discussions

31 Index Properties Atterberg limit is very important forthe characterization of soil within a broad category Thevariations of liquid limit and plastic limit with varyingpercentages of fly ash are shown in Figures 1 and 2 It is seenthat both the liquid limit and the plastic limit increase withthe increase of both types of fly ash content For example

International Scholarly Research Notices 3

0 2 4 6 8 10 12 14 16 18 2075

80

85

90

95

100

Type IType II

Ash content ()

Liqu

id li

mit

()

Figure 1 Variation of liquid limit with fly ash content

0 2 4 6 8 10 12 14 16 18 2050

55

60

65

70

75

80

85

90

Type IType II

Ash content ()

Plas

tic li

mit

()

Figure 2 Variation of plastic limit with fly ash content

for the Type I fly ash the liquid limit ranged from 85 to 94and the plastic limit ranged from 62 to 87 thus resulting ina decrease of plasticity index values ranging from 22 to 7while in the case of Type II fly ash the liquid limit rangedfrom 85 to 92 plastic limit ranged from 62 to 83 and plas-ticity index ranged from 22 to 9 Tastan et al [25] showedsimilar results and explained that these beneficial changesin engineering properties are mainly attributed to cationexchange flocculation of the clay agglomeration and poz-zolanic reactions For example rapid and immediate changesin plasticity occurred due to the cation exchange and floccu-lation of clay

0 10 20 30 40 50 60 70 80 90 1000

10

20

30

40

50

60

Organic soilType I Type II

10 1015 1520 20

ML amp OLML amp OL

CL

CH

Liquid limit ()

OH amp MH

Plas

ticity

inde

x (

)

ldquoArdquo line ０

） = 073 (LL-20)

Figure 3 Plasticity chart showing the original and fly ash treatedsoil

40

45

50

55

60

0 5 10 15 2070

75

80

85

90

MDDType IType II

OMC

Ash content ()

Type IType II

Max

imum

dry

den

sity d

(kN

Ｇ3)

Opt

imum

moi

sture

cont

ent w

()

Figure 4 Variation of maximum dry density and optimum mois-ture content with ash content

The plasticity chart shown in Figure 3 depicts the changein form of soil grains with the addition of fly ash This curverepresents the notion that the soil initially contained highplastic organic content and after the addition of ash itchanged its plasticity This change in form is attributed to theagglomeration of soil particles due to the production of cal-cium silicate gel This gel coats the soil clasts binding themtogether and filling the pores resulting in a reduction of waterabsorption and shrinkage as described by Okagbue [26]

32 Compaction Characteristics Figure 4 shows the effectof fly ash on the optimum moisture content (OMC) and


maximum dry density of soil It can be seen that the max-imum dry density decreases with the increasing amount offly ash while the optimum moisture content graduallyincreases for both types of soil This trend is similar to thatfound by Kaniraj and Havanagi [27] they described that thedecrease in the maximum dry density is attributed to the ag-glomeration and flocculation of clay particles through cationexchange reaction leading to the occupation of a larger spaceas well as reducing the weight volume ratio

On the other hand the optimummoisture content of soilincreases with the increase of fly ash content as more water isrequired for the formation of the lime-like product Ca(OH)2and dissolution of this product into Ca2+ and OHminus ions inorder to supply more Ca2+ ions for the cation exchange reac-tion Besides that the finer the surface area the more thewater required to provide good lubrication The ash contentalso decreases the quantity of free silt and clay fraction form-ing coarser materials which occupy larger spaces for retain-ing water

33 pH Kitazume [28] showed that cement and blast furnaceslag help to gain strength significantly when organic contentand humic acid are less than 15 and 09 respectively orpH is higher than 5 while humic acid consumes the calciumions in the binder of organic soil and does not always indicatesignificantly high strengths Tastan et al [25] also reportedthat there is no apparent relationship between 119902119906 or resilientmodulus and mixture pH The pH of the organic soil andash treated soil was determined according to ASTM D2976-15 [24] Figure 5 shows the variation of pH with ash contentand it is found that the pH value is higher for Type I fly ashtreated soil compared to Type II ash treated soil

34 Unconfined Compressive Strength (UCS) Unconfinedcompressive strengths (119902119906) of the soilndashfly ash mixtures pre-pared at their respective moisture content are shown as afunction of fly ash type in Figure 6 Triplicate specimenswere tested for unconfined compressive strength as qualitycontrol and the averages of these tests are reported as resultsAddition of fly ash to the organic soils resulted in a significantincrease in 119902119906 relative to that of the unstabilized soil It is clearfrom the figure that the final 119902119906 achieved varies dependingon the organic soil and the fly ash This is in contrast to thefindings reported for inorganic soils stabilized with differentfly ashes by Edil et al [29] forwhich final strengthswere com-parable although strength factors varied

The illustration shows that there is a rapid increase ofUCSwith the addition of ash content up to 15 and for the further5 ash content the UCS value increased gradually Thereason for this improvement is the formation of cementinggels (hydrate) due to the reactions between CaO of ash withAl2O3 and SiO2 of soil This results in the agglomeration oflarge size particles and causes the increase in compressivestrength In addition the compressive strength of fly ashtreated soil increases with the increases of curing times It isalso seen that compressive strength of Type II fly ash treatedsoil is higher compared to Type I fly ash treated soil

0 2 4 6 8 10 12 14 16 18 204

5

6

7

8

Type IType II

pH

Ash content ()

Figure 5 Variation of UCS with ash content

0 5 10 15 20 2520

30

40

50

60

70

80

90

100

Ash content ()

Type I Type II 3 days 3 days7 days 7 days28 days 28 days

Unc

onfin

ed co

mpr

essiv

e stre

ngth

(kPa

)


4 Conclusions

The effectiveness of fly ash for the improvement of uncon-fined compressive strength was investigated Two types of flyash Type I (classified as Class C) and Type II (classified asClass F) were used to stabilize the organic soil at Khulna CityBangladesh Based on the test results the following conclu-sions can be drawn

(i) The moisture content decreases and the dry densityincreases gradually for the addition of both types offly ash


(ii) Both values of liquid limit and plastic limit increaseand the plasticity index decreases with increasing per-centages of both types of fly ash content

(iii) The unconfined compressive strength increases withthe increasing percentages of fly ash content for bothtypes of fly ash

(iv) The unconfined compressive strength also increaseswith the increase of curing period

(v) The pH value increases with the increasing percent-ages of fly ash content for both types of fly ashstabilized organic soil

(vi) The Type I fly ash stabilized organic soil can producehigher strength and dry density than the Type II flyash stabilized organic soil So Type I fly ash is pre-ferable over Type II fly ash in order to improve thequality of soil

Finally it can be said that the properties of organic soilcan be improved by using fly ash but the amount of thisimprovement depends on the characteristics of organic soilas well as the properties and the amount of fly ash Furtherstudy is required to obtain the optimum amount of fly ash

Conflicts of Interest

The authors declare that there are no conflicts of interestregarding the publication of this paper

References

[1] J P Guyer An Introduction to Soil Stabilization for PavementsContinuing Education Development Engineering New YorkNY USA 2011

[2] G Sarkar M R Islam M Alamgir and M RokonuzzamanldquoStudy on the geotechnical properties of cement based compos-ite fine-grained soilrdquo International Journal of Advanced Struc-tures and Geotechnical Engineering vol 1 no 2 pp 42ndash49 2012

[3] G Sarkar R Islam M Alamgir and M RokonuzzamanldquoInterpretation of rice husk ash on geotechnical properties ofcohesive soilrdquo Global Journal of Researches in Engineering Civiland Structural Engineering vol 12 no 2 pp 1ndash7 2012

[4] M S Keshawarz andUDutta ldquoStabilization of south Texas soilswith fly ashrdquo in Fly Ash for Soil Improvement ASCE Geotechni-cal Special Publication no 36 1993

[5] A Sridharan and H B Nagaraj ldquoPlastic limit and compactioncharacteristics of fine-grained soilsrdquo Ground Improvement vol9 no 1 pp 17ndash22 2005

[6] S R Kaniraj and V G Havanagi ldquoCompressive strength ofcement stabilized fly ash-soil mixturesrdquo Cement and ConcreteResearch vol 29 no 5 pp 673ndash677 1999

[7] R L Parsons and E Kneebone ldquoField performance of fly ashstabilised subgradesrdquoGround Improvement vol 9 no 1 pp 33ndash38 2005

[8] SHorpibulsuk R Rachan andY Raksachon ldquoRole of fly ash onstrength and microstructure development in blended cementstabilized silty clayrdquo Soils and Foundations vol 49 no 1 pp 85ndash98 2009

[9] S Horpibulsuk C Phetchuay and A Chinkulkijniwat ldquoSoilstabilization by calcium carbide residue and fly ashrdquo Journal ofMaterials in Civil Engineering vol 24 no 2 pp 184ndash193 2012

[10] E Cokca ldquoUse of clas C fly ashes for the stabilization of anexpansive soilrdquo Journal of Geotechnical and GeoenvironmentalEngineering vol 127 no 7 pp 568ndash573 2001

[11] P G Nicholson and V Kashyap ldquoFlyash stabilization of tropicalHawaiian soilsrdquo in Fly Ash for Soil Improvement GeotechnicalSpecial Publication no 36 pp 15ndash29 ASCE New York NYUSA 1993

[12] H A Acosta T B Edil and C H Benson ldquoSoil stabilizationand drying using fly ashrdquo Geo Engineering Rep 3 2003

[13] G Ferguson ldquoUse of self-cementing fly ashes as a soil stabiliza-tion agentrdquo in Fly Ash for Soil Improvement (GSP 36) ASCENew York NY USA 1993

[14] J Prabakar N Dendorkar and R K Morchhale ldquoInfluence offly ash on strength behavior of typical soilsrdquo Construction andBuilding Materials vol 18 no 4 pp 263ndash267 2004

[15] S Bin-Shafique T Edil C Benson andA Senol ldquoIncorporatinga fly-ash stabilised layer into pavement designrdquo Proceedings ofthe Institution of Civil EngineersmdashGeotechnical Engineering vol157 no 4 pp 239ndash249 2004

[16] B D Trzebiatowski T B Edil and C H Benson ldquoCase studyof subgrade stabilization using fly ash state highway 32 PortWashington Wisconsinrdquo in Recycled Materials in Geotechnics(GSP 127) pp 123ndash136 ASCE Reston VA USA 2005

[17] G Sarkar S Siddiqua R Banik and M RokonuzzamanldquoPrediction of soil type and standard penetration test (SPT)value in Khulna City Bangladesh using general regressionneural networkrdquo Quarterly Journal of Engineering Geology andHydrogeology vol 48 no 3-4 pp 190ndash203 2015

[18] ASTM ldquoStandard test methods for moisture ash and organicmatter of peat and other organic soilsrdquo ASTMD2974-14 ASTMInternational West Conshohocken Pa USA 2014

[19] ASTM ldquoStandard specification for coal fly ash and raw orcalcined natural pozzolan for use in concreterdquo ASTM C618-15ASTM International West Conshohocken Pa USA 2015

[20] ASTM ldquoStandard practice for characterizing fly ash for use insoil stabilizationrdquo ASTM D5239-12 ASTM International WestConshohocken Pa USA 2012

[21] A Senol T B Edil M S Bin-Shafique H A Acosta and C HBenson ldquoSoft subgradesrsquo stabilization by using various flyashesrdquo Resources Conservation and Recycling vol 46 no 4 pp365ndash376 2006

[22] ASTM ldquoStandard test methods for laboratory compactioncharacteristics of soil using standard effort (12 400 Ft-lbfft3(600 kN-mm3)rdquo ASTMD698-12e2 ASTM InternationalWestConshohocken Pa USA 2012

[23] ASTM ldquoStandard test method for unconfined compressivestrength of compacted soil-lime mixturesrdquo ASTM D5102-09ASTM International West Conshohocken Pa USA 2009

[24] ASTM ldquoStandard test method for pH of peat materialsrdquo ASTMD2976-15 ASTM International West Conshohocken Pa USA2015

[25] E O Tastan T B Edil C H Benson and A H Aydilek ldquoSta-bilization of organic soils with fly ashrdquo Journal of Geotechnicaland Geoenvironmental Engineering vol 137 no 9 pp 819ndash8332011

[26] C O Okagbue ldquoStabilization of clay using woodashrdquo Journal ofMaterials in Civil Engineering vol 19 no 1 pp 14ndash18 2007


[27] S R Kaniraj andVGHavanagi ldquoBehavior of cement-stabilizedfiber-reinforced fly ash-soil mixturesrdquo Journal of Geotechnicaland Geoenvironmental Engineering vol 127 no 7 pp 574ndash5842001

[28] M Kitazume ldquoState of practice reportmdashfield and laboratoryinvestigations properties of binders and stabilized soilrdquo in Pro-ceedings of the International Conference on Deep Mixing BestPractice and Recent Advances Swedish Deep StabilizationResearch Centre Linkoping Sweden 2005

[29] T B Edil CH BensonM S Bin-Shafique B F TanyuWKimand A Senol ldquoField evaluation o f construction alternatives for-roadways over soft subgraderdquo Journal of TransportationResearch Record vol 1786 no 1 pp 36ndash48 2002

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Control Scienceand Engineering

Journal of


International Journal of

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Hindawi Publishing Corporation httpwwwhindawicom

Journal of

Volume 201

Submit your manuscripts athttpswwwhindawicom

VLSI Design



Shock and Vibration


Civil EngineeringAdvances in

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Modelling amp Simulation in EngineeringHindawi Publishing Corporation httpwwwhindawicom Volume 2014


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Navigation and Observation



DistributedSensor Networks



Table 1 Index properties of soil

Property name ValuesUnit weight (kNm3) 1117Liquid limit 119908119871 () 852Plastic limit 119908119875 () 6253Plasticity index 119868119901 () 2267Shrinkage limit 119908119904 () 2819Shrinkage ratio SR 124Water content w () 8712Specific gravity 119866119904 219pH 637Organic content () 369Classification

USCS OHAASHTO

to 22∘581015840010158401015840 north and longitude 89∘281015840010158401015840 to 89∘371015840010158401015840 east Itis a linear shaped city with an elevation from 9m in the northto 2m towards the southwest direction from the mean sealevel comprising very soft to soft consistency up to 20 ft fromthe ground surface levelThe generalized investigation resultsshowed that the soils in the northern and southern part aremainly composed of clay with silt and organic deposits themiddle eastern part comprises sand with some clay and amoderate type of soil is found in the middle western partwhich includes mainly silt with clay and sand It has beenfound that the organic soil exists here at a depth of 10 to25 ft below the existing ground surface and the organiccontent of this soil ranges from 5 to 70 and even morein some instances It is seen that most of the region of thisarea contains fine-grained soil with some organic depositswhich have lower bearing capacity and are not good forshallow foundations for buildings and roadways HoweverKhulna City is progressing with several development projectsincluding construction of high-rise buildings oil storagetanks long span bridges harbors port structures floodprotection embankments and barrages Since all structuralloads are transferred to soil the characteristics of soil playa vital role in the safety of these structures [17] In thisstudy the effectiveness of fly ash on the strength and densityof the organic soil of Khulna region was investigated Inaddition the quantity of fly ash that optimizes the unconfinedcompressive strength of stabilized organic soil was also esti-mated at different curing days

2 Materials and Methods

21 Soils The soft organic soil having organic content of369 was collected from Beel Dakatia Shiromoni KhulnaSamples were collected within a depth of about 15m from theexisting ground surface The collected soil was kept in a largepolythene bag and dried in air for about 7 days Table 1 showsthe physical and index properties of the organic soil ASTMD2974-14 [18] It is seen that the soil contains high liquid limitlow unit weight and high water content

Table 2 Chemical composition and physical properties of fly ash

Composition or property Type I Type IIChemical composition

Silica (SiO2) 502 656Alumina (Al2O3) 225 25Iron oxide (Fe2O3) 517 6Lime (CaO) 203 178Sulphates (SO3) 039 03Magnesia (MgO) 051 07

Physical propertiesFineness (specific surface) by Blainersquos 3746 300permeability method (m2kg)Sieving on 45-micron residue () 1782 705Loss on ignition () 402 400Insoluble residue () 9074 9600Moisture () 018 2

22 Fly Ashes Fly ash is a very fine powdery material com-posed mostly of silica which is a product of burning finelyground coal in a boiler to produce electricity Two types of flyash were collected from locally available cement industries inthe southern part of Khulna The chemical composition andphysical composition of Type I and Type II are summarizedin Table 2 According to ASTMC 618 Type I fly ashes classifyas Class C ash and Type II fly ashes classify as Class F [19 20]It is found that Class C fly ashes are finer compared to ClassF fly ashes while the other physical properties remained thesame Moreover the CaO and CaOSiO2 content of Class Ffly ashes is lower than that of the Class C fly ashes ThereforeClass C fly ashes offer a more economical alternative as a soilstabilizing agent because of their pozzolanic characteristicsThis type of fly ash provides the opportunity for applicationswhere other activators would not be required [21]

23 Experimental Method Standard Proctor compactiontests were carried out to determine the optimum moisturecontent and maximum dry density of all fly ash-soil mixturesaccording to ASTM D698-12e2 [22] Cylindrical sampleshaving a diameter of 38mm and height of 76mm used in theUCS test were prepared at their corresponding optimummoisture content and maximum dry density by static com-paction For curing the samples were closely wrapped in apolythene bag and placed above water in a desiccator kept ina roomThe unconfined compressive strength of the sampleswas assessed according to ASTM D5102-09 [23] The indexproperties of the organic soil and fly ash treated soil weredetermined according to ASTM D2976-15 [24]

3 Results and Discussions

31 Index Properties Atterberg limit is very important forthe characterization of soil within a broad category Thevariations of liquid limit and plastic limit with varyingpercentages of fly ash are shown in Figures 1 and 2 It is seenthat both the liquid limit and the plastic limit increase withthe increase of both types of fly ash content For example


0 2 4 6 8 10 12 14 16 18 2075

80

85

90

95

100

Type IType II

Ash content ()

Liqu

id li

mit

()


0 2 4 6 8 10 12 14 16 18 2050

55

60

65

70

75

80

85

90

Type IType II

Ash content ()

Plas

tic li

mit

()



0 10 20 30 40 50 60 70 80 90 1000

10

20

30

40

50

60


10 1015 1520 20

ML amp OLML amp OL

CL

CH

Liquid limit ()

OH amp MH

Plas

ticity

inde

x (

)


） = 073 (LL-20)


40

45

50

55

60

0 5 10 15 2070

75

80

85

90

MDDType IType II

OMC

Ash content ()

Type IType II

Max

imum

dry

den

sity d

(kN

Ｇ3)

Opt

imum

moi

sture

cont

ent w

()










0 2 4 6 8 10 12 14 16 18 204

5

6

7

8

Type IType II

pH

Ash content ()


0 5 10 15 20 2520

30

40

50

60

70

80

90

100

Ash content ()


Unc

onfin

ed co

mpr

essiv

e stre

ngth

(kPa

)


4 Conclusions












References































RoboticsJournal of





Journal of



RotatingMachinery



Journal of

Volume 201


VLSI Design



Shock and Vibration







Journal of



Volume 2014


SensorsJournal of





Propagation










0 2 4 6 8 10 12 14 16 18 2075

80

85

90

95

100

Type IType II

Ash content ()

Liqu

id li

mit

()


0 2 4 6 8 10 12 14 16 18 2050

55

60

65

70

75

80

85

90

Type IType II

Ash content ()

Plas

tic li

mit

()



0 10 20 30 40 50 60 70 80 90 1000

10

20

30

40

50

60


10 1015 1520 20

ML amp OLML amp OL

CL

CH

Liquid limit ()

OH amp MH

Plas

ticity

inde

x (

)


） = 073 (LL-20)


40

45

50

55

60

0 5 10 15 2070

75

80

85

90

MDDType IType II

OMC

Ash content ()

Type IType II

Max

imum

dry

den

sity d

(kN

Ｇ3)

Opt

imum

moi

sture

cont

ent w

()










0 2 4 6 8 10 12 14 16 18 204

5

6

7

8

Type IType II

pH

Ash content ()


0 5 10 15 20 2520

30

40

50

60

70

80

90

100

Ash content ()


Unc

onfin

ed co

mpr

essiv

e stre

ngth

(kPa

)


4 Conclusions












References































RoboticsJournal of





Journal of



RotatingMachinery



Journal of

Volume 201


VLSI Design



Shock and Vibration







Journal of



Volume 2014


SensorsJournal of





Propagation















0 2 4 6 8 10 12 14 16 18 204

5

6

7

8

Type IType II

pH

Ash content ()


0 5 10 15 20 2520

30

40

50

60

70

80

90

100

Ash content ()


Unc

onfin

ed co

mpr

essiv

e stre

ngth

(kPa

)


4 Conclusions












References































RoboticsJournal of





Journal of



RotatingMachinery



Journal of

Volume 201


VLSI Design



Shock and Vibration







Journal of



Volume 2014


SensorsJournal of





Propagation


















References































RoboticsJournal of





Journal of



RotatingMachinery



Journal of

Volume 201


VLSI Design



Shock and Vibration







Journal of



Volume 2014


SensorsJournal of





Propagation













RoboticsJournal of





Journal of



RotatingMachinery



Journal of

Volume 201


VLSI Design



Shock and Vibration







Journal of



Volume 2014


SensorsJournal of





Propagation









study on strength behavior of organic soil stabilized with...

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