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International Journal of Civil Engineering and Technology (IJCIET) Volume 8, Issue 9, September 2017, pp. 353–360, Article ID: IJCIET_08_09_041

Available online at http://http://www.iaeme.com/ijciet/issues.asp?JType=IJCIET&VType=8&IType=9

ISSN Print: 0976-6308 and ISSN Online: 0976-6316

© IAEME Publication Scopus Indexed

INFLUENCE OF NANOSIZED SILICA AND

LIME PARTICLES ON THE BEHAVIOUR OF

SOIL

Dr. P. Eswaramoorthi

Professor, Department of Civil Engineering,

Kumaraguru college of Technology, Coimbatore, India

V. Senthil Kumar and P. Sachin Prabhu

Assistant Professor, Department of Civil Engineering,


T. Prabu

Assistant Professor, Department of Civil Engineering,

Builders Engineering College, Tirupur, India

S. Lavanya

UG Student, Department of Civil Engineering,


ABSTRACT:

Nanotechnology is the science that deals with the particles which are less than 100

mm. The size of the Nano particles plays a crucial role in behaviour of soil exhibiting

different properties. Use of these Nano particles in stabilization influences shear

strength, dry density of the soil and makes more reactive to soil because of its high

specific surface area. In this investigation, an attempt is made to investigate the

influence of ball milled Nano silica and lime particles in the improvement of soil.

Results indicated that compare to non-nano particles in soil, the nano admixed soil

yielded UCC strength of 589 kN/m2 which is 1.2 times higher than non-nano particles.

Cite this Article: Dr. P. Eswaramoorthi, V. Senthil Kumar, P. Sachin Prabhu, T.

Prabu and S. Lavanya, Influence of Nanosized Silica and Lime Particles on the

Behaviour of Soil, International Journal of Civil Engineering and Technology, 8(9),

2017, pp. 353–360.

http://www.iaeme.com/IJCIET/issues.asp?JType=IJCIET&VType=8&IType=9

Dr. P. Eswaramoorthi, V. Senthil Kumar, P. Sachin Prabhu, T. Prabu and S. Lavanya


1. INTRODUCTION

Presence of weak soil in the construction sites is a major issue for any type of construction.

To enhance the properties of the weak soil, many methods like soil stabilization, soil

reinforcement, grouting, addition of admixtures etc. are adopted. Addition of admixtures like

Lime, fly ash, Cement, bitumen based on type of soil improves the properties of soil to some

extent. Use of industrial waste as additives is recently under study, but it arises a question of

toxicity. So there is a need for finding a new innovative material.

One of the new innovative fields recently introduced to soil is Nanotechnology.

Nanotechnology is recently been introduced to Geotechnical Engineering. Nanotechnology is

the science that deals with the particles which are less than 100 nm. The size of the Nano

particles plays a crucial role in behaviour of soil exhibiting different properties.

Laboratory experiments conducted by Taha [1] to study the fundamental geotechnical

properties of mixtures of natural soils and its product after ball milling mixture. Lab results

showed that the value of Atterberg limits were higher after Nano-soil addition. However, its

plasticity index reduces which is advantageous in many geotechnical constructions.

Compressive strength of original soil Cement and 1% Nano soil mixture showed double its

value without Nano soil. Thus Nano particles are potentially suitable for improving the

properties of soil/clay for various applications.

The addition of different Nano materials, including Nano Cu, Nano MgO and Nano clay

on the geotechnical properties of soft soil sample from Peneng state was described by Zaid

Hameed Majeed and Taha [2]. The unconfined compressive strength increased as the Nano

material content increased up to a certain percentage in the soil and then decreased afterwards.

Noll, Bartlett and Dochat [3] investigated the use of nano silica particles in enhancing soil

strength against consolidation and permeability. The hydraulic conductivity of soil was

reduced by 3- 4 folds with addition of Nano silica.

2. MATERIALS

2.1. Soil

The soil was collected from Perumbakkam, Chennai at shallow depth after removing the top

0.5 depth soil.

Table 1 Index Properties of Soil

Properties Values

Specific gravity 2.60

Clay % 82

Silt % 14

Sand % 6

Liquid Limit % 80

Plastic Limit % 32

Plasticity Index % 48

Free swell Index % 60

Soil Classification CH

Table 1 shows the index properties of soil. The soil is classified as CH type and based on

FSI value the soil gets high swell classification. The Maximum dry density of the soil is

1.52g/cc and OMC is 25.74%. From Unconfined compression test, it was found that the shear

strength of the soil alone is 254 kN/m2

at OMC.

Influence of Nanosized Silica and Lime Particles on the Behaviour Of Soil


2.2. Additives and their characterization

The two different additives silica and lime were collected and stored. Lime powder collected

from local market. Silica powder collected from Chettinad Moorrum Private Limited, OMR

road, Chennai, Tamilnadu. From HRTEM analysis the particle sizes of raw Silica in the range

of 2µ - 14µ and Lime in the range of 30µ - 150µ were calculated. Chemical composition of

the additives was obtained by EDAX test. Results shows that Silica consists nearly 50% of

silica and lime consisted 31% calcium and 17% magnesium as its major contributed

chemicals.

3. METHODOLOGY

Silica and lime are taken as additives to mix with soil. Silica is mixed with soil upto 15%

(5%, 10% &15%) with the addition of lime from 2% to 10% (2%, 6% & 10%). For the

optimum mix, Nano materials of those additives mixed with soil and tested. Nano materials

were prepared by using ball milling. Characterization test carried out on unmilled additive and

milled additive to compare particle size and chemical composition. The index properties,

compaction test, UCC test were carried out in soil and Nano materials. These identical

samples were prepared for their maximum dry density at optimum water content based on

compaction curves obtained. The samples are tested for 7 days curing.

3.1. Preparation of Nano Particles

Nano particles are commonly prepared by bottom up method and top down method. Top

down method begin with bulk materials (top) that are subsequently reduced into

Nanostructures (down) by the way of physical, chemical and mechanical processes for

examples mechanical ball-milling, grinding etc. Preparation of Nano particles has done by

planetary ball milling. A specific quantity of (about 100gms) silica and lime milled for 6 hrs

and for 12 hrs respectively.

Figure 1 HRTEM images of ball milled SILICA particles

Figure 2 HRTEM images of ball milled LIME particles



From HRTEM analysis, the particle sizes of milled Silica in the range of 24nm - 72 nm

and milled Lime in the range of 31nm – 62nm were calculated (figure 1 and figure 2). After

ball milling process, particle size got reduced compare to raw additives.

4. RESULTS AND DISCUSSIONS

Influence of Non - Nano Sized Additives on the Index, Compaction and UCC

Strength Properties of Soil

4.1.1. Effect of Silica + Lime Mix on Index Properties of Soil

The effect of silica and lime mix with soil on liquid limit is presented in fig 3 and 4. Fig 3

shows the liquid limit of soil is decreased linearly for 5%, 10% and 15% of silica admixed

soil with addition of lime and beyond that, the liquid limit value is nearly constant for further

increment of lime.

Figure 3 Effect of lime content on liquid limit of soil + silica mix

Figure 4 Effect of silica content on liquid limit of soil + lime mix

Figure 5 Effect of lime content on plasticity index of soil+silica mix



From fig 5, it is observed that the plasticity index of soil is decreased for 5%, 10% and

15% silica admixed soil with increase in lime content.

Figure 6 Effect of silica content on plasticity index of soil +lime mix

The plasticity index of silica admixed soil is decreased for increase in lime content upto

4% as inferred from figure 6. Beyond 4% lime content, the variation in plasticity index of

silica admixed soil is almost marginal.

4.1.2. Effect of Silica + Lime Mix on Compaction Characteristics of Soil

As per IS 2720 part VII, compaction test is carried out for the soil alone and soil mixed with

additives. The value of maximum dry density and corresponding optimum moisture content

are inferred from compaction curves. The results are tabulated below in table 2.

Table 2 Effect of Silica-Lime mix on the compaction characteristics of soil

Description γ dmax (g/cc) OMC (%)

Soil alone 1.52 25.74

Soil+5%Silica

2% Lime 1.50 26.31

6% Lime 1.49 26.80

10% Lime 1.48 27.01

Soil+10%Silica

2% Lime 1.47 27.86

6% Lime 1.46 28.03

10% Lime 1.46 28.75

Soil+15%Silica

2% Lime 1.45 28.98

6% Lime 1.44 29.21

10% Lime 1.43 29.81

From proctor compaction test, the γ dmax values are 1.50g/cc, 1.47 g/cc and 1.45 g/cc

respectively for 5%, 10%, 15% silica with 2% lime. The OMC values are in the range of

26.31% to 28.98%.

For 6% lime, the γ dmax values are 1.49g/cc, 1.46 g/cc and 1.44g/cc respectively for 5%,

10%, 15% silica. The OMC values are in the range of 26.80% to 29.21%. The γ dmax values

Pla

stic

ity I

nd

ex, %

% of Lime

5%

Si…



are 1.48g/cc, 1.46 g/cc and 1.43g/cc respectively for 5%, 10%, 15% silica admixed with 10%

lime. The OMC values are in the range of 27.01% to 29.81%.

The optimum moisture content did not vary much for varying % silica unlike γ dmax. The

reduction in γ dmax is expected because of the low specific gravity silica replaces soil and

thereby the γ dmax decreases, Sridharan and Prakash [4] and James K. Mitchel [5].

The γ dmax is always lower in soil for any % of silica and lime. Compare to the effect of

lime, the role of silica is significant in reducing γ dmax values. The OMC value increases

steeply with % of lime. This is due to enhanced water holding capacity of soil-silica-lime mix

due to the formation of flocculated structure.

4.1.3. Effect of Silica + Lime Mix on UCC Strength of Soil

From the stress-strain curves for soil with increasing % of silica with 2% to 10% lime, the

UCC peak strength is determined and presented in this section with reference to silica

independently for varying lime. All the UCC strength values are corresponding to 7 days

cured UCC specimens.

Figure 7 Effect of lime on the UCC strength of soil+ silica mix

As seen from figure 9 and 10, the UCC strength is always higher in soil + 10% silica for

2% and 6% of lime compared to soil + 5% silica and soil + 15% silica with varying % lime.

The optimum % for effective utilization of soil + silica + lime mix seems to be 5% silica +

10% lime.

Figure 8 Effect of silica on the UCC strength of soil+ lime mix

UC

C S

tren

gth

, k

N/m

2

% of Lime

5%

Sil…

UC

C

Str

ength

, k

N/m

2

% Silica

2 % lime

6% lime

10% lime



4.2. Influence of Nano Sized Additives on the Index, Compaction and UCC

Strength Properties of Soil

Table 3 compares the influence of nano particles and non-nano particles on the index

properties of soil. The liquid limit, plastic limit and plasticity index non-nano particles of 5%

silica+10% lime in soil are 49%, 36% and 13% respectively. In the case of 5% nano

silica+10% nano lime in soil, the values are 58%, 37% and 21% respectively. The nano

particles produced higher plasticity characteristics compared to non-nano particles. This

mainly because of enhanced surface area of nano particles which eventually give raise to

more water holding capacity resulting in high plasticity characteristics.

The γ dmax and OMC of soil+5% nano silica+10% nano lime are 1.42g/cc and 32.03%

and whereas for the same combination, non-nano particles admixed soil produce the γ dmax

value of 1.45g/cc and OMC of 27%. The lesser value of γ dmax and higher value of OMC of

nano particles admixed soil are mainly because of enhanced specific surface area because of

particle fineness.

The UCC strength of soil alone is 254kN/m2, and that of soil+non nano particles of 5%

silica+10% lime is 493 kN/m2. In the case of soil+5% nanosilica + 10% nano lime, the peak

strength 589 kN/m2.

Compare to non-nano particles in soil, the nano admixed soil yielded UCC strength of 589

kN/m2 which is 1.2 times higher than non-nano particles. The higher strength of nano

particles admixed soil is mainly due to higher reactivity of silica and lime with the soil

because of the enhanced specific surface area.

Table 3 Effect of Nano sized silica and lime on the Index, Compaction and UCC strength properties

Description LL% PL % PI % ϒd max g/cc OMC % UCC Strength

kN/m2

Soil alone 80 32 48 1.52 25.74 254

5% Silica + 10%

Lime 49 36 13 1.45 27.01 493

5% Nano Silica +

10% Nano Lime 58 37 21 1.42 32.03 589

5. HYDRAULIC CONDUCTIVITY OF NANO PARTICLES ADMIXED

SOIL

The co-efficient of permeability (k) of soil was determined using falling head permeability

test with a mould diameter of 7.5cm and effective height 6cm. The permeability test was

conducted on compacted soil+ additive mix corresponding to the ϒdmax and OMC of the mix

constituents.

Table 4 Co-efficient of permeability of nano particles admixed soil

Description Permeability ‘k’

cm/sec

Soil Alone 4.95 X 10-6

5% Silica + 10% Lime 2.92 X 10-6

5% Nano Silica + 10% Nano Lime 1.97 X 10-7

The co-efficient of permeability of soil alone is 4.95 X 10-6

cm/sec. This value has

reduced to 2.92 X 10-6

for soil+5% silica+ 10% lime. The ‘k’ value reduced to almost a fold.

The ‘k’ value of for soil + 5%silica + 10% lime is 1.97 X 10-7

cm/sec.



This result clearly indicates that of the soil particles could effectively fill the void of the

soil particles and thereby soil-additives matrix becomes less permeable nature. In this case,

compared to non-nano particles, nano particles could effectively fills the pores of soil

particles owing to its fineness and hence results in lower permeability values.

6. CONCLUSIONS

Based on the analysis of results, the following conclusions may be drawn.

1. Addition of Nano sized silica and lime additives on soil decreases the liquid limit and

plasticity Index values and increases the plastic limit values. Decrease in liquid limit

and plasticity index was more than non-Nano sized additive mixtures with soil.

2. The maximum dry density of soil with addition of 5% Nano Silica + 10% Nano Lime

decreases the dry density to 1.42 gm/cm3 with increase in OMC of 32%.

3. For addition of 5% Silica and 10% lime the UCC strength increased to 493 kN/m2

with 7 days curing. Upon adding Nano sized particles of Silica and Lime the same

value increased up to 589kN/m2 with 7days curing.

4. The Nano particles admixed soil yielded the co-efficient of permeability; 10 times

lower than that of non-nano sized additives silica and lime.

REFERENCES

[1] Taha.,(2009), A review of stabilization of Soils by using Nano materials Australian

Journal of Basic and Applied Sciences, 7(2) ISSN 1991-8178, pp.576-581

[2] Zaid Hameed Majeed and Mohd Raihan Taha, (2010), Effect of Nano material treatment

on geotechnical properties of a penang soft Soil, Journal of Asian Scientific Research,

pp.587-592

[3] Noll M.R., Bartlett C, and Dochat T.M. (1992), In situ Permeability Reduction and

Chemical Fixing Using Colloidal Silica, Proceedings of the 6th National Outdoor Action

Conference, National Ground Water Association, Las Vegas, NV, pp 443-457.

[4] Sridharan. A and K.Prakash, (2007), Geotechnical engineering characterisation of coal

ashes, 3rd

Ed, CBS publishers, New Delhi, India.

[5] James K. Mitchel and Kenichi Soga, (2005), Fundamentals of Soil Behaviour, 3rd

Ed, John

Wiley & Sons, New York, USA.

[6] E Balaji, Dr. S Senthil Selvan and Vishnu Prasad P R, An Experimental Study on the

Effect of Nano Silica on Strength and Durability of Concrete. International Journal of

Civil Engineering and Technology, 8(4), 2017, pp. 1182–1188.

[7] S. Prasath, Dr. S. Senthil Selvan and E. Balaji, Experimental Study of Nano Silica and

Silica Fume Concrete Column Subjected To Corrosion. International Journal of Civil

Engineering and Technology, 8(3), 2017, pp. 708–719

[8] V. Nagendra, C. Sashidhar, S. M. Prasanna Kumar and N. Venkata Ramana GGBS and

Nano Silica (NS) Effect on Concrete. International Journal of Civil Engineering and

Technology, 7(5), 2016, pp.477 – 484.

influence of nanosized silica and lime particles on … · builders engineering college, tirupur,...

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