Abd El-Aziz, Abo-Hashema, and El-Shourbagy 1

The Effect of Lime-Silica Fume Stabilizer on Engineering Properties 

of Clayey Subgrade 

By 

Dr. Magdy A. Abd El-Aziz Dr. Mostafa A. Abo-Hashema 

Assistant Professor, Dept. of Civil Engineering Assistant Professor, Dept. of Civil Engineering 

Cairo University – Fayoum Branch Cairo University – Fayoum Branch 

Ph. +2010-527-3502, Fax. +208-433-4031 

 

Dr. Mahmoud El-Shourbagy 

Associate Professor, Dept. of Civil Engineering 

Mansoura University 

ABSTRACT 

The engineering properties of clayey subgrade soils may need to be improved to make them 

suitable for construction using some sort of stabilization methods. Stabilization of pavement 

subgrade soils has traditionally relied on treatment with lime, cement, or waste materials such as 

Silica Fume (SF). Most transportation agencies, however, are hesitant to specify these 

nontraditional stabilizers without reliable data to support vendor claims of product effectiveness. 

The main objective of this study is to investigate the effect of the engineering properties of 

clayey soils when blended with lime and SF. A series of laboratory experiments have been 

implemented for varieties of samples: 1%, 3%, 5%, 7%, 9% and 11% for lime and 5%, 10% and 

15% for SF. The results from the Lime-Silica Fume (LSF) blend confirmed that the blend would 

diminish swell behavior of clayey soils. Their Plasticity Index and swell potential would 

decrease from 40.25% to 0.98% and from 19.0% to 0.016%, respectively, when subjected to a 

LSF blend of 11-15%. Their California Bearing Ratio value would increase from 3.0% to 17.0% 

at a LSF blend of 5-15%. Their internal friction angle concerning shear strength parameters 

would enhance from 5.80 to 24.75. Soil cohesion increased as well from 55.52 kN/m2

 to 157.54 

kN/m2

. At LSF 5-10%, consolidation settlement was lowered from 0.025 to 0.007. All of these 

results can be summarized to say that by blending Lime and Silica Fume together, the 

engineering properties of clayey soils can be enhanced. 

KEYWORDS 

Engineering Properties, Soil Stabilization, Subgrade, Clayey Soils, Silica Fume, Lime 
Abd El-Aziz, Abo-Hashema, and El-Shourbagy 2

INTRODUCTION 

A difficult problem in civil engineering work exists when the subgrade is found to be clay. Clay 

soils having high clay content have a tendency to swell when their moisture content is allowed to 

increase [1]. This moisture may come from rains, floods, leaking sewer lines, or from the 

reduction of surface evaporation when an area is covered by a building or pavement. Frequently, 

these clayey soils cause the cracking and breaking up of pavements, railways, highway 

embankments, roadways, foundations and channel or reservoir linings [2]. 

Most of the agricultural roads in the Egyptian road network were originally constructed as a 

canal or drain embankments. These embankments are molded with high percent of clay and they 

generally have high swell potential and are not favorable when used for construction where 

construction damages are possible [3]. When civil engineers are faced with possible construction 

damage, a need for improving the engineering properties of the soil is justified using some sort 

of stabilization methods. Stabilization of pavement subgrade soils has traditionally relied on 

treatment with lime, cement, and special additives such as Pozzolanic materials. Pozzolanic 

materials, such as Fly Ash, Silica Fume, and Rice Husk Ash, which are regarded as wastes may 

be used for soil improvement as indicated in recent research [4]. The Silica Fume is found to be 

40% cheaper than that of Portland cement. 

Most transportation agencies, however, are hesitant to specify such these nontraditional 

stabilizers without reliable data to support vendor claims of product effectiveness. The main 

objective of this study is to investigate the effect of blending clayey soils with lime and SF 

together on their engineering properties. A series of laboratory experiments have been 

implemented on varieties of samples by blending both Lime and Silica Fume together. These 

samples were 1%, 3%, 5%, 7%, 9% and 11% for lime and 5%, 10% and 15% for SF. 

SOIL STABILIZATION 

Definition 

Soil Stabilization in its broadest sense implies the improvement of both durability and strength of 

soil. Soil may be improved by adding the deficient particle sizes to give a more satisfactory 

grading. A process known as mechanical stabilization or in other instances cement, lime, 

bitumen, or special additives are used to bind or waterproof the particles of soil and so increase 

its strength and durability. Cement treatment is most applied to road stabilization especially 

when the moisture content of the subgrade is very high. Waste materials or nontraditional 

stabilizers, such as Silica Fume and Fly Ash, are also sometimes applied for stabilization. When 

the soil has been treated with any of the mixtures mentioned above, thus is called stabilized soil 
Abd El-Aziz, Abo-Hashema, and El-Shourbagy 3

[5]. This study focuses on using Lime and Silica Fume together as a stabilizer material for clayey 

soils. 

Lime Stabilizer 

Calcium hydroxide (slaked lime) is most widely used for stabilization. Calcium oxide (quick 

lime) may be more effective in some cases; however, the quick lime will corrosively attack 

equipment and may cause severe skin burns to personnel. Ingles (1972) recommended the 

criteria of lime mixture as show in Table 1 [6]. 

Silica Fume Stabilizer 

Silica Fume (SF), also known as micro-silica, is a byproduct of the reduction of high-purity 

quartz with coal in electric furnaces in the production of silicon and ferrosilicon alloys. SF is also 

collected as a byproduct in the production of other silicon alloys such as ferrochromium, 

ferromanganese, ferromagnesium, and calcium silicon [7]. Before the mid-1970s, SF was 

discharged into the atmosphere. After environmental concerns necessitated the collection and 

landfilling of Silica Fume, it became economically justified to use Silica Fume in various 

applications. 

SF consists of very fine vitreous particles with a surface area on the order of 20,000 m2/kg 

(215,280 ft2

/lb) when measured by nitrogen absorption techniques, with particles approximately 

100 times smaller than the average cement particle. Because of its extreme fineness and high 

silica content, Silica Fume is a highly effective pozzolanic material [7,8]. Silica Fume is used in 

concrete to improve its properties. It has been found that SF improves compressive strength, 

bond strength, and abrasion resistance; reduces permeability; and therefore helps in protecting 

reinforcing steel from corrosion. 

SF is available in two conditions: dry and wet. Dry silica can be provided as produced or 

densified with or without dry admixtures and can be stored in silos and hoppers. Silica Fume 

slurry with low or high dosages of chemical admixtures are available. Slurried products are 

stored in tanks with capacities ranging from a few thousand to 400,000 gallons (1,510 m3) 

[9,10]. 

SF is a pozzolanic material that could be potentially used in Egypt, considering it is sufficiently 

produced and is widespread. When SF was allowed to burn under controlled temperature, higher 

pozzolanic properties were observed. Silica is a main mineral of SF. When reacted with lime, it 

will form a bonded gel [Ca (SiO3)]. The composition of SF minerals is shown in Table 2 [11]. 
Abd El-Aziz, Abo-Hashema, and El-Shourbagy 4

REACTION MECHANISM OF POZZOLANIC MATERIALS 

Lime reacts with any other fine pozzolanic component (such as Silica Fume) to form calciumsilicate cement with soil particles. This reaction is also water insoluble. The cementing agents are 

exactly the same for ordinary Portland cement. The difference is that the calcium silicate gel is 

formed from the hydration of anhydrous calcium silicate (cement), whereas with the lime, the gel 

is formed only by the removal of silica from the clay minerals of the soil. The pozzolanic process 

may be written as: 

Ca (OH)2 + SiO2 C-S-H (1) 

Ca (OH)2 + Al2O3 C-S-H (2) 

(Note: Calcium Silicate Hydrate, C-S-H, is cemented material). 

The silicate gel proceeds immediately to coat and bind clay lumps in the soil and to block off the 

soil voids in the manner shown by Figure 1. In time, this gel gradually crystallizes into welldefined calcium silicate hydrates such as tobermorite and hillebrandite. The micro-crystals can 

also mechanically interlock. The reaction ceases on drying, and very dry soils will not react with 

lime or cement. The mechanism of the reaction can be represented as: 

NAS4H + CH → NH + CAS4H → NS + degradation product* (3) 

 NH + C2SH**  (2CH) 

Where: S = SiO2, H = H2O, A = Al2O3, C = CaO, N = Na2O. 

* As silica is progressively removed, calcium aluminates and alumina are formed residually 

** Or CSH 

MATERIALS TESTED 

Stabilizer Product: Lime and Silica Fume 

The stabilizer materials used in this study were Lime and Silica Fume (LSF). Lime material was 

taken from a quarry located in Beni-Suif, Egypt and Silica Fume products were brought from 

Ferrosilicon Alloys Company (Edfo-Komombo), Aswan, Egypt. Hydrated lime in powder form 

was used for the lime material. It is noteworthy that SF has a high degree of water absorption. 

When SF reacted with lime, it will form a bonded gel [Ca (SiO3)]. The composition of SF 

minerals is presented before in Table 2. 
Abd El-Aziz, Abo-Hashema, and El-Shourbagy 5

Test Soils 

The clayey soils involved in this research were dug from an area in Fayoum, Egypt. The soil 

sample was disturbed. The physical characterization of clay sample is presented in 
Abd El-Aziz, Abo-Hashema, and El-Shourbagy 6

Table 3. The soil is classified as Silty Clay (Gs = 2.625 with 90.25% fines) with expansive 

behavior. The chemical element of tested materials is presented in Table 4. 

Specimen Preparation 

Test samples were mixed from pulverized, air-dry soil and de-ionized water. Treated specimens 

were prepared following the nine-step protocol outlined here. Untreated control specimens were 

prepared in the same manner, but without the addition of the stabilizer product (LSF). 

1. Using the modified Proctor compaction test [12], the Optimum Moisture Content (OMC) 

for compaction was determined for the untreated soil. These values are listed in (
Abd El-Aziz, Abo-Hashema, and El-Shourbagy 7

Table 3). 

2. Based on the product literature, the recommended percentages of the stabilizer product 

were as follow: 1%, 3%, 5%, 7%, 9% and 11% for lime and 5%, 10% and 15% for SF. 

3. The test soil was pre-moistened to a natural moisture content = 70.65 (
Abd El-Aziz, Abo-Hashema, and El-Shourbagy 8

Table 3). The soil was mixed dry of optimum at this point to allow for the water that 

would be added with the stabilizer in Step 6. 

4. The pre-moistened soil was allowed to mellow for at least 16 hours in a sealed container. 

5. The mass of stabilizer needed to achieve the recommended OMC in the treated sample 

was measured out. 

6. The stabilizer was thoroughly mixed with the soil sample, which was then allowed to 

stand for 1 hour in a covered container. If there were no evaporation losses, the soil water 

content would now be equal to the OMC. 

7. The treated soil was compacted using a modified Proctor effort [12], extruded from the 

compaction mold, and sealed in a plastic bag. 

8. The compacted soil was cured in a sealed plastic bag at room temperature for 7 days. 

9. The cured sample was trimmed to an appropriate size for testing. If the specimen water 

content was more than 3% above or below the OMC, new specimens were prepared using 

adjusted initial water content. Almost all test specimens were within ±2% of the target 

OMC. 

A seven-day curing period was selected as a reasonable delay to allow reactions between the 

stabilizer and the soil prior to conducting the evaluation tests. Laboratory assessments of soil 

stabilizers often include a 28-day cure following treatment; the additional three weeks may, 

depending on the stabilizer, yield additional changes in the soil properties. However, it is 

expected that significant changes due to an effective soil treatment should be measurable at 

seven days. 

It is noteworthy that all specimens, whether untreated or treated, were compacted at the same 

optimum water content. In this study, however, the same water content was used to prepare all 

specimens of a given soil, so that the effect of the stabilizer on the measured soil properties could 

be distinguished from the effects of varying the water content. For the same reason, the samples 

were maintained at constant water content during the curing period. 

Laboratory Experiments 

A series of laboratory experiments have been conducted for varieties of samples. These 

experiments are to measure the engineering properties of the soil as follow: 

• Physical Properties 

o Specific Gravities 

o Consistency Limits 

o Swelling 

• Grain Size Distribution 

• Compaction Characterization 

• California Bearing Ratio 

• Triaxial Test 
Abd El-Aziz, Abo-Hashema, and El-Shourbagy 9

• Consolidation Test 
Abd El-Aziz, Abo-Hashema, and El-Shourbagy 10

ANALYSIS OF THE RESULTS 

Physical Properties 

Based on the laboratory experiments, the soil is classified as Silty Clay (Gs = 2.625 with 90.25% 

fines) with expansive behavior. Soil with PI > 35% is classified to have very high swell potential 

[1], where LL and PI of the sample is respectively 72.45% and 40.25%. The effect of blended 

LSF on the physical properties of soil can be shown as in Figure 2, Figure 3, and Figure 4. 

Specific Gravities 

Specific Gravities (Gs) for the untreated and treated soils were determined and the results were 

plotted in Figure 2. As shown in Figure 2, by adding LSF the specific gravity of the soil 

decreases. This indicates that the soil is lighter than that of its natural conditions. 

Consistency Limits 

The Atterberg limits for the untreated and treated soils were determined following ASTM D 

4318 [13]. The treated soil samples were allowed to cure for seven days before testing but were 

not compacted. The results are plotted in Figure 3 (a), (b), and (c). Figure 3 shows the influence 

LSF has on consistency limits. Figure 3(c) shows that the PI of the soil decreases when lime 

content is increased. 

Swelling Potential 

To measure the potential expansiveness of the untreated and treated soils, free swell tests were 

conducted in accordance with ASTM D 4546 [14]. To get better measurement precision, onedimensional swell tests were selected over unconfined three-dimensional swell tests. The 

compacted and cured soil specimens were trimmed into 63-mm diameter oedometer rings to a 

thickness of 19 mm; the trimmed montmorillonite specimens were 10 mm thick to allow for their 

much greater expansion. After applying a vertical seating pressure of about 2.4 kPa, the soil was 

inundated with water, which could seep into the sample through top and bottom porous stones. 

The swell results are presented in Figure 4, which indicates that swell potential decreases as well. 

The lowest value was attained by an 11-15% LSF blend. 
Abd El-Aziz, Abo-Hashema, and El-Shourbagy 11

Grain Size Distribution 

The effect of LSF on the Grain Sieve of clayey soil is presented in Figure 5. Figure 5 (a) and (b) 

show that there is a decrease of finer particles. 

Compaction Characterization 

Moisture-unit weight curves for all the untreated test soils were determined using a modified 

proctor compaction effort [12]. This established OMC for preparing all of the compacted soil 

specimens for subsequent swell and triaxial testing. 

In Figure 6, influence of LSF on Maximum Dry Density (MDD) and OMC of clayey soil is 

presented. Figure 6 represents that by increasing LSF content in soil, MDD tends to decrease, 

whereas OMC increases. Decreasing MDD indicates that compaction energy is less than the 

natural state. Increasing OMC tends to be prevalent when lime was added. 

Compaction characterization of clayey soil with Blended by LSF is plotted in Figure 7. Note that 

the water contents of many test specimens were a little dry of the target optimum, due to 

evaporation losses during mixing. However, considering the normal variability obtained in 

preparing compacted soil samples, there appears to be no significant effect of the stabilizer 

treatments on the compacted soil unit weight or void ratio. Figure 7 shows that soil, which has 

been blended with lime, is best to be compacted in the wet optimum state. Therefore, blended 

LSF has a place in construction work where a soil's moisture content is very high. 

California Bearing Ratio and Consolidation Parameter 

Results of California Bearing Ration (CBR Laboratory) and Consolidation Parameter of soil with 

blended by LSF are presented in Figure 8. Figure 8 (a) reveals a trend to enhance and attain the 

optimum CBR value at 5% lime content and a 5-15% maximum of SF. Figure 8 (b) shows the 

compressibility index (Cc) tends to be non-linear. This condition exhibits that when the rate of 

consolidation is rapid, the settlement of the soil will reduce. 

Shear Strength 

To measure soil strength, unconsolidated-undrained triaxial compression tests were conducted 

following ASTM D 2850 [15]. The shear strength of highway materials is often characterized 

using unconfined compression tests, but testing in a triaxial cell yields a more reliable measure of 

strength. This is especially true for fissured, compacted soils where the confining pressure keeps 

the specimen intact under load. The compacted and cured soil samples were trimmed into test 
Abd El-Aziz, Abo-Hashema, and El-Shourbagy 12

specimens measuring 38 mm in diameter by 95 mm high. During shearing, volumetric strains 

were measured from changes in the volume of cell fluid. The cross-sectional area of each 

specimen was corrected using the axial and volume strains and assuming a right-circular cylinder 

shape. Typical results, from UU triaxial tests, are plotted in Figure 9. Stress-Strain behavior of 

clayey soil under Triaxial Test is presented in Figure 10. 

Figure 9 shows that the addition of lime increases the shear strength parameter, cohesion, and the 

internal angle of friction. Lime dominated the cohesion properties of the soil, whereas SF 

interferes with the internal angle of friction. Furthermore, the soil strength is enhanced. Figure 9 

(c) shows that the maximum ultimate strength is attained at a 9% SF content. Figure 10 shows 

brittle behavior of the soil when mixed with LSF. 

Therefore, it can be concluded that lime and Silica Fume can improve the engineering properties 

of clayey soils. Practically, the effective lime content and Silica Fume should be blended in the 

range of 5-9% and 10% respectively. 

CONCLUSIONS 

Lime can be used as soil stabilizer to improve the engineering properties of clayey subgrade. In 

addition, waste materials such as Silica Fume (SF) can also be used as nontraditional stabilizer 

for clayey subgrade. SF is a byproduct of the reduction of high-purity quartz with coal in electric 

furnaces in the production of silicon and ferrosilicon alloys. This paper examines the effect of 

adding Lime and Silica Fume (LSF) together on the engineering properties of clayey soils. A 

series of laboratory experiments have been conducted for varieties of samples: 1%, 3%, 5%, 7%, 

9% and 11% for lime and 5%, 10% and 15% for Silica Fume. It was found that the engineering 

properties of soil have been improved by adding Lime in the range of 5-9% combined with a 

10% Silica Fume. Furthermore, the physical properties such as consistency limits and swell 

potential show improvements when mixed with the LSF blend. Economically, utilization of LSF 

for geotechnical applications is cheaper. 

REFERENCES 

1. Chen, F.H., 1981. Foundation on Expansive Soil, Development in Geotechnical 

Engineering 12. Elsevier Scientific Publishing Company, New York, USA. 

2. Cokça, E., 1999. Effect of Fly Ash on Swell Pressure of an Expansive Soil, Electronic 

Journal of Geotechnical Engineering, Paper 9904. Oklahoma State University, USA. 

3. Abo-Hashema, M.A., Darrag, A.A. and El-Mitiny, M.R., 1994. Instability of Rural Roads 

on Canal Embankments, Diagnosis and Solutions, The Arab Road Association, 2nd 

Edition, pp 18-34. 
Abd El-Aziz, Abo-Hashema, and El-Shourbagy 13

4. Muntohar, A.S., 1999a, Effect of Lime and Rice Husk Ash on the Behavior of Soft Clay, 

Regional Seminar at Islamic University of Indonesia Sept. 4th 1999. Yogyakarta, 

Indonesia. 

5. Yoder, E.J. and Witczak, M.W., 1975. Principles of Pavement Design, 2nd Edition, John 

Wiley & Sons, Inc., USA 

6. Ingles, O.G., Metcalf, J.B., 1972. Soil Stabilization, Principles and Practice, John Wiley 

& Son’s, Sydney, Australia. 

7. ACI Committee 226. 1987b. Silica fume in concrete: Preliminary report. ACI Materials 

Journal March-April: 158-66. 

8. Luther, M. D. 1990. High-performance silica fume (microsilica)—Modified cementitious 

repair materials. 69th Annual Meeting of the Transportation Research Board, paper no. 

890448 (January). 

9. Admixtures and ground slag for concrete. 1990. Transportation research circular no. 365 

(December). Washington: Transportation Research Board, National Research Council. 

10. Holland, T. C. 1988. Practical Considerations for Using Silica Fume in Field Concrete. 

67th Annual Meeting of the Transportation Research Board, paper no. 87-0067 (January). 

11. Abd El Aziz, M, 2003. The Effect of Silica Fume Substitution on the Characteristics of 

Ordinery Portland Cement Pastes and Mortars, Civil Engineering Magazine, Vol. 24 No. 

2, April 2002, p. 715-725, Egypt. 

12. American Society for Testing and Materials. Standard Test Method for Laboratory 

Compaction Characteristics of Soil Using Modified Effort (56,000 ft-lb/ft3, 2,700 kNm/m3). ASTM D 1557-91, 1998 Annual Book of ASTM Standards, West Conshohocken, 

Pa. 

13. American Society for Testing and Materials. Standard Test Method for Liquid Limit, 

Plastic Limit, and Plasticity Index of Soils. ASTM D 4318-95a, 1998 Annual Book of 

ASTM Standards, West Conshohocken, Pa. 

14. American Society for Testing and Materials. Standard Test Methods for OneDimensional Swell or Settlement of Cohesive Soils. ASTM D 4546-96, 1998 Annual 

Book of ASTM Standards, West Conshohocken, Pa. 

15. American Society for Testing and Materials. Standard Test Method for UnconsolidatedUndrained Triaxial Compression Tests on Cohesive Soil. ASTM D 2850-95, 1998 

Annual Book of ASTM Standards, West Conshohocken, Pa. 
Abd El-Aziz, Abo-Hashema, and El-Shourbagy 14

Table 1: Suggested Lime Content 

Soil Type Content For Modification Content For Stabilization 

Fine crushed rock 2 – 4 percent Not recommended

Well graded clay gravels 1 – 3 percent ~ 3 percent

Sands Not recommended Not recommended

Sandy clay Not recommended ~ 5 percent

Silty clay 1 – 3 percent 2 – 4 percent

Heavy clay 1 – 3 percent 3 – 8 percent

Very heavy clay 1 – 3 percent 3 – 8 percent

Organic soils Not recommended Not recommended

Table 2: Chemical Composition of Silica Fume Minerals 

Mineral Composition (%) 

SiO2 95 

Al2O3 0.6 

Fe2O3 0.8 

CaO 0.2 

MgO 0.5 

SO3 0.1 

Na2O 0.2 

K2O 0.3 

F.L. 0.45 

I.L. 1.2 
Abd El-Aziz, Abo-Hashema, and El-Shourbagy 15

Table 3: Physical Characterization of Clay Sample 

Physical properties Test result 

Natural moisture content, wN 

Moisture content (disturbed) 

Specific Gravity, Gs 

Atterberg Limits1: 

Liquid Limit, LL 

Plastic Limit, PL 

Shrinkage Limit, SL 

Plasticity Index, PI 

Maximum Dry Density, γd

Optimum Moisture Content 

Grain size distribution: 

 - Coarse particles 

 - Fine particles 

 - Clay 

 - Silt 

Activity 

70.65 

18.35 

2.625 

72.45 

31.87 

13.55 

40.250 

1.38 gr/cm3

33 

9.45 

90.25 

11.00 

81.43 

3.470 

1

 Liquid Limit, Plastic Limit, Shrinkage Limit, and Plasticity Index, ASTM D 4318 [13] 

2

 Optimum water content for compaction with a modified Proctor effort, ASTM D 1557 [12] 

Table 4: Chemical Element of Tested Materials 

Chemical 

Elements Clay (%) SF (%) Hydrated Lime (%) 

SiO2 50.78 95 0.00 

Al2O3 17.58 0.6 0.15 

Fe2O3 8.87 0.8 0.07 

CaO 3.75 0.2 58.78 

MgO 1.09 0.5 0.27 

Na2O 1.84 0.2 0.06 

K2O 0.41 0.3 0.03 

MnO 0.27 0.0 0.005 

TiO2 0.94 0.00 0.00 

P2O5 0.16 0.0 0.00 

H2O 4.19 1.33 0.04 

HD 9.35 0.95 40.48 
Abd El-Aziz, Abo-Hashema, and El-Shourbagy 16

Figure 1: Reaction Mechanism of stabilization on Clay Soils [6] 

2.44

2.48

2.52

2.56

2.60

2.64

2.68

0 1 2 3 4 5 6 7 8 9 10 11

Lime Content (%)

Specific Gravity (Gs)

SF 0%

SF 5%

SF 10%

SF 15%

Figure 2: Effect of Blended LSF on the Specific Gravity of Soil 
Abd El-Aziz, Abo-Hashema, and El-Shourbagy 17

20%

30%

40%

50%

60%

70%

80%

0 1 2 3 4 5 6 7 8 9 10 11

Lime Content (%)

Liquid Limits (LL)

SF 0%

SF 5%

SF 10%

SF 15%

0%

10%

20%

30%

40%

50%

60%

70%

0 1 2 3 4 5 6 7 8 9 10 11

Lime Content (%)

Plastic Limits (PL)

SF 0%

SF 5%

SF 10%

SF 15%

0%

5%

10%

15%

20%

25%

30%

35%

40%

45%

50%

0 1 2 3 4 5 6 7 8 9 10 11

Lime Content (%)

Plasticity Index (PI)

SF 0%

SF 5%

SF 10%

SF 15%

Figure 3: Influence of LSF on the Consistency Limits 

(a) Liquid Limits (LL), (b) Plastic Limits (PL), 

and (c) Plasticity Index (PI) 
Abd El-Aziz, Abo-Hashema, and El-Shourbagy 18

0%

5%

10%

15%

20%

25%

0 1 2 3 4 5 6 7 8 9 10 11

Lime Content (%)

Swell (%)

SF 0%

SF 5%

SF 10%

SF 15%

Figure 4 Influence of LSF on the Swelling Potential 

0%

20%

40%

60%

80%

100%

0 1 2 3 4 5 6 7 8 9 10 11

Lime Content (%)

Finer (%)

SF 0%

SF 5%

SF 10%

SF 15%

0%

20%

40%

60%

80%

100%

0 1 2 3 4 5 6 7 8 9 10 11

Lime Content (%)

Coarse (%)

SF 0%

SF 5%

SF 10%

SF 15%

Figure 5: Effect of LSF on the Grain Sieve of Clayey soil 

(a) Finer Particle of Soil and (b) Coarse Particle of Soil 
Abd El-Aziz, Abo-Hashema, and El-Shourbagy 19

1.00

1.05

1.10

1.15

1.20

1.25

1.30

1.35

0 1 2 3 4 5 6 7 8 9 10 11

Lime Content (%)

MDD (gm/cm3)

SF 0%

SF 5%

SF 10%

SF 15%

20%

25%

30%

35%

40%

45%

50%

0 1 2 3 4 5 6 7 8 9 10 11

Lime Content (%)

OMC

SF 0%

SF 5%

SF 10%

SF 15%

Figure 6: Influence of LSF on MDD and OMC of Clayey Soil 

(a) Maximum Dry Density (MDD) and (b) Optimum Moisture Content (OMC) 

0.70

0.80

0.90

1.00

1.10

1.20

1.30

1.40

1.50

1.60

0% 10% 20% 30% 40% 50% 60% 70% 80%

Water Content (%)

γ d (gr/cm3

)

LSF 0- 5%

LSF 0-10%

LSF 0-15%

Expon. (Zero

Void Line) 0.70

0.80

0.90

1.00

1.10

1.20

1.30

1.40

1.50

1.60

0% 10% 20% 30% 40% 50% 60% 70% 80%

Water Content (%)

γ d (gr/cm3

)

LSF 1-0%

LSF 3-0%

LSF 5-0%

LSF 7-0%

LSF 9-0%

LSF 11-0%

Expon. (Zero

Void Line)

Figure 7: Compaction Characterization of Clayey Soil with Blended by LSF 
Abd El-Aziz, Abo-Hashema, and El-Shourbagy 20

0%

2%

4%

6%

8%

10%

12%

14%

16%

18%

0 1 2 3 4 5 6 7 8 9 10 11

Lime Content (%)

CBR

SF 0%

SF 5%

SF 10%

SF 15%

0.0E+00

5.0E-03

1.0E-02

1.5E-02

2.0E-02

2.5E-02

3.0E-02

3.5E-02

0 1 2 3 4 5 6 7 8 9 10 11

Lime Content (%)

Cc

SF 0%

SF 5%

SF 10%

SF 15%

Figure 8: California Bearing Ration (CBR Laboratory) and Consolidation Parameter of Soil with Blended by 

LSF 

(a) CBR Laboratory and (b) Compressibility Index (Cc) 

0

500

1000

1500

2000

2500

3000

3500

4000

4500

0 1 2 3 4 5 6 7 8 9 10 11

Lime Content (%)

qu (kPa)

SF 0%

SF 5%

SF 10%

SF 15%

0

5

10

15

20

25

30

0 1 2 3 4 5 6 7 8 9 10 11

Lime Content (%)

φ (o

)

SF 0%

SF 5%

SF 10%

SF 15%

0

20

40

60

80

100

120

140

160

180

0 1 2 3 4 5 6 7 8 9 10 11

Lime Content (%)

C (kPa)

SF 0%

SF 5%

SF 10%

SF 15%

Figure 9: Effect of LSF on the Shear Strength of Clayey Soil 

(a) Shear Strength of Soil (qultimate), (b) Internal Friction Angle (ω), and (c) Cohesion 
Abd El-Aziz, Abo-Hashema, and El-Shourbagy 21

0

100

200

300

400

500

600

700

0 5 10 15

Strain (%)

Ds (kPa)

LSF 0-5%

LSF 0-10

LSF 0-15%

0

100

200

300

400

500

600

700

0 5 10 15

Strain (%)

Ds (kPa)

LSF 7-0%

LSF 9-0%

LSF 11-0%

LSF 9-10%

Figure 10: Stress-Strain Behavior of Clayey Soil under Triaxial Test