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International Journal of Applied Engineering Research ISSN 0973-4562 Volume 13, Number 10 (2018) pp. 8684-8694
© Research India Publications. http://www.ripublication.com
8684
Strength and Hydraulic Conductivity of Cement and By - Product
Cementitious Materials Improved Soil
*Samuel Jonah Abbey1, Samson Ngambi2, Adegoke Omotayo Olubanwo3, and Francis Kofi Tetteh4
1Lecturer in Structural/Geotechnical Engineering, University of South Wales, United Kingdom.
2Senior Lecturer in Soil Mechanics and Geotechnics, Coventry University, United Kingdom.
3Lecturer in Structural Engineering and Finite Element, Coventry University, United Kingdom.
4PhD Candidate Birmingham University, and Senior Geotechnical Engineer, Aspin Group, United Kingdom.
(* Corresponding author)
Abstract
This paper presents an experimental investigation on strength
and hydraulic conductivity of a fine grained soil mixed with
cement, Pulverised Fly Ash and Ground Granulated Blast Slag.
Strength and permeability are important properties that defines
the engineering behaviour of deep mixing improved soils.
Cement contents of 4%, 8%, 12% and 16% by weight of dry
soil were added using wet soil mixing technique. The
percentages of cement were reduced and replaced with PFA,
GGBS and Bentonite at 33.3% and 50% reductions
respectively. Unconfined compressive strength (UCS) and
permeability tests were conducted on cement, PFA/GGBS and
Cement/Bentonite mixtures prepared at their respective
optimum moisture content (OMC) and maximum dry density
(MDD) and cured for different periods. The results show that
an increase in % of additives causes decrease in porosity and
increase in density of cement and cement/PFA stabilised soil
and hence, increase in UCS. Except at some optimum values of
12% and 16% of additives in C+PFA combinations where the
density of the improved soil decreases at fairly constant
porosity resulting to an increase in UCS. This implies that % of
additive and the type of additive controls the UCS of improved
soils more than the influence of porosity and density on UCS.
Decrease in porosity of samples improved using
C+PFA+GGBS and C+B with increase in % of additives,
resulted to increase in UCS but however, the reduction in
density and increase in UCS also shows dominance of % and
type of additive on strength over porosity and density. Cement-
Bentonite and combination of PFA /GGBS with reduced
amount of cement were observed to better improved
permeability of the soil. This study has also defined the
functional relationships between hydraulic conductivity and
additive type based on the investigated % of additives and
combinations.
Keywords: Strength, Permeability, Hydraulic conductivity,
Deep Soil Mixing, Improved Soil, Cement, PFA, GGBS,
Bentonite, fine grained soil
INTRODUCTION
Weak soils are generally regarded as problematic in terms of
their resistance to shear deformation, hydraulic conductivity,
excessive settlement and limited bearing capacity. Deep soil
mixing is one technique that has been used to improve these
properties and enhanced performance, (Abbey et al. 2015; Eyo,
et al., 2017; Terashi, 2009; Abbey et al. 2017, Mousavi and
Wong 2016). The inclusion of different binder type and cement
during soil mixing process can generate similar hydration
products, (Abdulhussein Saeed, Anuar Kassim, and Nur 2014).
The unconfined compressive strength of Portland cement (PC)
improved soils are usually high making PC the most commonly
used binder in soil improvement, (Holm, Terashi, 2003;
Makusa 2012; Consoli et al. 2015; Oana, 2016, Abbey et al.
2016). Chen, Liu and Lee (2016) examined the variation in
unconfined compressive strength of marine clay, improved
with cement during wet deep mixing work at the Marina Bay
Financial Centre in Singapore. In their study, the UCS of the
improved clay was found to vary from about 700 kPa to about
5 MPa. The 28 day UCS of samples improved with cement and
prepared using wet mixing method is always higher than those
prepared by dry method, Pakbaz and Farzi (2015). According
to Chen, Liu and Lee (2016), strength distribution in deep
mixing improved soils is affected by in-situ soil properties and
the chemical reactions between soil and Cementitious
constituent. UCS increases with increase in cement content
especially for non-plastic soils (Asturias and Lorenzo 2015,
Abbey et al., 2016, 2017). For applications of soil mixing in
ground water barrier walls, the permeability of the improved
soil, defines the hydraulic conductivity of the barrier walls and
of great importance. Enhancement of permeability of soil
formations is also important in construction of other hydraulic
structures such as dams, power houses, tunnels and in a wide
variety of special cases. Cement - bentonite mixture has been
used in the UK for impermeable cut-off slurry walls (Talfirouz
2013) and it has also been used severally in the US to form
permeable reactive barriers(PRB) in contaminated soil
(Bullock 2007). Åhnberg (2003) and Higgins, (2005) observed
that cement-based binders significantly reduces the
International Journal of Applied Engineering Research ISSN 0973-4562 Volume 13, Number 10 (2018) pp. 8684-8694
© Research India Publications. http://www.ripublication.com
8685
permeability of tested Swedish soil while lime-based binders
produced more rapid result in terms of increase in permeability.
Yi, Liska and Al-Tabbaa (2013) reported the initial increase in
permeability upon addition of lime and cement as being due to
hydration reaction that takes place when quick lime and the
lime content in cement comes in contact with soil pore water.
This reaction causes flocculation of the clay, forming a coarser
structure than that of the natural soil owing to the formation of
Ca(OH)2 and ion exchange with soil particles (Åhnberg 2003,
2006). Mousavi and Wong (2016) reported that permeability of
cement stabilised clay reduces as cement content increase from
8% to 18% and according to EuroSoilStab (2002), the
permeability of a soil can increase up to 100 to 1000 times when
stabilized with binders. Mixture of cement and bentonite has
also been used to consistently reduce permeability with
increasing cement content and this combination is commonly
used in construction of hydraulic impermeable barriers (Takai,
2014) but establishing the percentage of cement and bentonite
required to enhance hydraulic conductivity of a fine grained
soil would be considered in this paper. According to (Wang et
al., (2015), Puppala (2003), Axelsson et al. (2002),
Keramatikerman et al., (2016) and Ali et al. (2013)) use of
cement, lime, PFA and GGBS in soil stabilisation can improve
the strength property of a weak soil. Undoubtedly, cement deep
soil mixing has been widely employed in the construction field
and has effectively reduced soil permeability. But lately,
problems particularly associated with cost and the
environments have emerged due to CO2 emission. Therefore, it
becomes necessary to investigate into the possible use of by-
product materials such as PFA and GGBS with reduced amount
of cement in deep mixing of weak soils to possibly reduce the
environmental impact of cement soil mixing operations.
Therefore, this study will also focused on the effect of inclusion
of cementitious by-product materials with reduced amount of
cement on unconfined compressive strength and hydraulic
conductivity of a fine-grained soil and establish the functional
relationship between percentage of additive and hydraulic
conductivity.
MATERIALS
Model soil and additives
The model soil consisted of a silty soil of 24% moisture
content, liquid and plastic limits of 47.8% and 24.3%
respectively. The untreated model soil has hydraulic
conductivity of 4.4 x 10-10 under effective stresses of 200kPa
and unconfined compressive strength (UCS) of 145kPa as
presented in Table 1.0 The binders considered are cement,
GGBS, PFA and cement-bentonite. The hydration of cement in
the presence of water involves different reactions often
occurring at the same time and the product of this reaction (C-
S-H) gradually bond particles of the improved soil together and
consequently enhances strength. The investigated soil has been
treated with cement and inclusion of by-product cementitious
materials such as GGBS and PFA based on the environmental
concern on the use of cement. Ground improvement projects,
especially in remediation of contaminated sites, soil bentonite
mixtures have been used to form slurry wall hydraulic barriers
based on the hydrophilic property of bentonite and ability to
absorb organic contents. Cement-bentonite mixtures have been
employed in the UK as impermeable cut-off slurry walls
(Talfirouz 2013) and in the US as permeable reactive barriers
in contaminated soil (Bullock 2007). The chemical
compositions and physical properties of the materials used are
shown in Table 2.0 and Table 3.0 respectively.
Table 1.0: Physical properties of untreated soil
Properties Characteristic values
Water content, w (%) 27
Liquid limit, wl (%) 47.8
Plastic Limit, wp (%) 24.3
Plasticity index, IP (%) 23.5
Hydraulic conductivity, k (m/s) 4.4 x 10-10
UCS (kPa) 145
Table 2.0 Chemical compositions of Cement, PFA and GGBS
Binder
Oxides (%)
SiO2 TiO2 Al2O3 Fe2O3 MnO MgO CaO Na2O K2O P2O5 SO3 LOI
CEM I
19.63
0.26
4.71
3.25
0.09
1.17
64.09
0.27
0.73
0.20
2.94
3.22
PFA
52.15
0.87
19.61
7.10
0.07
2.00
4.40
1.06
1.93
0.45
0.54
9.48
GGBS
33.28
0.57
13.12
0.32
0.316
7.74
37.16
0.33
0.474
0.009
2.21
4.42
International Journal of Applied Engineering Research ISSN 0973-4562 Volume 13, Number 10 (2018) pp. 8684-8694
© Research India Publications. http://www.ripublication.com
8686
Table 3.0 Compositions and other properties of bentonite
Typical Chemical Analysis
Typical Mineralogy
Other Typical Properties
SiO2 57.1% Na2O 3.27% Montmorillonite 92%
Bulk Density 800–900 kg/m3
Al2O3 17.79% K2O 0.9% Calcite 4%
Swelling Volume 29 ml/2g
Fe2O3 4.64% TiO2 0.77% Feldspars 2% Moisture Maximum 14% by weight
CaO 3.98% Mn2O3 0.06% Quartz 1%
Cation Exchange Capacity 78 meq/100g
MgO 3.68% LOI 7.85% Dolomite 1%
- -
METHODOLOGY
Sample preparation and test procedure
The investigated soil was treated in four phases using Cement,
blend of Cement and PFA, Cement/PFA/GGBS and
Cement/Bentonite. In the first phase of mixing, cement
contents of 4%, 8%, 12% and 16% by weight of dry soil were
added using wet soil mixing technique, (Abbey et al., 2017).
The second phase of mixing consisted of Cement/PFA
improved soils with a 50% reduction in Cement content and
inclusion of equal amount of PFA. In the third phase, Cement
content was further reduced to 33.33% and replaced with equal
amounts of PFA and GGBS to produce Cement/PFA/GGBS
improved soil, (Abbey, et al., 2017). Finally, the 50% Cement
reduction as were in the second phase was replaced with equal
amount of Bentonite. In all, the total percentage of binder was
kept constant, summing up to 4%, 8%, 12% and 16%. During
mixing, the percentage of water added to each mix
corresponded to the optimum moisture content of the individual
mix. All improved samples were then sealed, wrapped with a
thick plastic and cured under water for 7 and 28days
respectively. The coefficient of permeability was evaluated for
90% degree of consolidation (U = 90%) using Taylor’s
settlement-root time method of curve fitting. The laboratory
testing program was designed to determine the strength and
hydraulic conductivity of the improved and unimproved
samples. The Atterberg limit and oedometer test were
conducted following the procedures outlined in BS 1377-
2:1990 and 1377-5:1990 respectively. The permeability
properties of the samples were determined through one-
dimensional consolidation test in a standard oedometer using
incremental loading up to a maximum effective stress of
200kPa.
RESULTS AND DISCUSSION
In this study, the joint activation of fly ash/ground granulated
blast furnace slag (GGBS) mixtures has been evaluated to find
its suitability in geotechnical and geo-environmental
applications in terms of strength and hydraulic conductivity.
Permeability is an important soil property that defines the
hydraulic conductivity of the soil. This soil property is
influenced by a wide range of factors, ranging from soil
sedimentation and particle size distribution, to the stress history
of the soil. The chemical reactions between binder or mixture
of binders and soil pore water and particles can contributes
significantly to changes in properties of the stabilized soil
material. These binder-soil reactions can also vary with binder
types; however, formation of similar hydration products at the
end of the reaction stages is obtainable. The major hydration
products formed, which includes calcium silicate hydrate gel
(CSH) and calcium aluminate hydrate gel (CASH) may vary in
quantity depending on the chemical composition of the binders.
This paper has investigated the performance of a fine-grained
soil in terms of strength and hydraulic conductivity at varying
percentages of binders and binder combinations. The author has
used the terms unstabilized and unimproved soil
interchangeably, to refer to the untreated states of the
investigated soil sample in terms of its index and mechanical
properties. The term hydraulic conductivity has also been used
interchangeably with the term coefficient of permeability to
refer to the ease by which water flows through soils. The results
plotted in Figure 1.0(a-d) and Figure 1.0(e-h) show the
variation of void ratio of the stabilized soil with effective stress
for different binder types and combinations.
International Journal of Applied Engineering Research ISSN 0973-4562 Volume 13, Number 10 (2018) pp. 8684-8694
© Research India Publications. http://www.ripublication.com
8687
Figure 1.0(a-d): Variation of void ratio of stabilised soils with effective stress
0.500
0.600
0.700
0.800
0.900
1.000
1.100
1 10 100 1000
Vo
id r
atio
, e
log p (kPa)
Cement - 7days
Unstabilized 6C 8C 12C 16C
0.500
0.600
0.700
0.800
0.900
1.000
1.100
1 10 100 1000
Vo
id r
atio
, e
log p(kPa)
Cement+ Bentonite - 7days
Unstabilized 3C+3B 4C+4B
6C+6B 8C+8B
(b)
0.500
0.600
0.700
0.800
0.900
1.000
1.100
1 10 100 1000
Vo
id r
atio
,e
log p (kPa)
Cement +PFA - 7days
Unstabilized 3C+3PFA 4C+4PFA
6C+69FA 8C+8PFA
(c)
0.500
0.600
0.700
0.800
0.900
1.000
1.100
1 10 100 1000
Vo
id r
atio
, e
log p (kPa)
Cement+PFA+GGBS - 7days
Unstabilized2C+2PFA+2GGBS2.667C+2.67PFA+2.67GGBS4C+4PFA+4GGBS5.33C+5.33PFA+5.33GGBS
(d)
(a)
International Journal of Applied Engineering Research ISSN 0973-4562 Volume 13, Number 10 (2018) pp. 8684-8694
© Research India Publications. http://www.ripublication.com
8688
Figure 2.0(e-h): Variation of void ratio of stabilised soils with effective stress after 28-days
The results show reduction in void ratio with increase in
effective stress as expected, due to increase in overburden.
Irrespective of binder types, void ratio decreases with an
increase in % of binder due to bonding effect of additives with
solid soil particles. The inclusion of by-product cementitious
materials increases the volume of solid particles and bonding
area. The void ratio of the improved soils decrease as the % of
binder combinations increases. However, 8% cement-bentonite
mix shows almost linear and lower variation in void ratio with
increasing overburden after 7 and 28days as shown in Figure
1.0(b) and Figure 1.0 (h). This is due to the expansive behaviour
of bentonite when in contact with water.
Effect of porosity and density on UCS
In a study on use of fly ash and GGBS as partial replacement
of cement and lime by (Chao, Songyu and Yongfeng 2015), it
was observed from a microstructural analysis that fly ash
mainly alters the distribution of pore volume of the soil, and
produces more hydration compounds as a result of secondary
hydration and pozzolanic reactions. The present study has
investigated other properties of soil improved using
combination of this additives with reduced amount of cement.
The effect of porosity and density on unconfined compressive
strength (UCS) has been investigated. The results show that an
increase in % of additives causes decrease in porosity and
increase in density of cement and cement/PFA stabilised soil
0.500
0.550
0.600
0.650
0.700
0.750
0.800
0.850
0.900
0.950
1.000
1 10 100 1000
Vo
id r
atio
, e
log p(kPa)
Cement - 28days
Unstabilized 6C8C 12C16C
(e)
0.500
0.600
0.700
0.800
0.900
1.000
1.100
1 10 100 1000
Vo
id r
atio
, e
log p (kPa)
Cement+PFA - 28days
Unstabilized 3C+3PFA4C+4PFA 6C+6PFA8C+8PFA
(f)
0.500
0.600
0.700
0.800
0.900
1.000
1.100
1 10 100 1000
Vo
id r
atio
, e
log p(kPa)
Cement+PFA+GGBS - 28days
Unstabilized
2C+2PFA+2GGBS
2.67C+2.67PFA+2.67GGBS
4C+4PFA+4GGBS
5.33C+5.33PFA+5.33GGBS
(g)
0.500
0.600
0.700
0.800
0.900
1.000
1.100
1 10 100 1000
Vo
id r
atio
, e
log p (kPa)
Cement+Bentonite - 28days
Unstabilized 3C+3B
4C+4B 6C+6B
8C+8B
(h)
International Journal of Applied Engineering Research ISSN 0973-4562 Volume 13, Number 10 (2018) pp. 8684-8694
© Research India Publications. http://www.ripublication.com
8689
and hence, increase in UCS. Except at higher % of additive
(12% and 16% of additives) in C+PFA combinations as shown
in Figure 4.0, where the density of the improved soil decreases
at fairly constant porosity resulting to increase in UCS. This
implies that the % of additive and type of additive controls the
UCS of improved soils more than the influence of porosity and
density on UCS. This means that UCS depends more on the %
of additive and the type of additive than on porosity and density
of the improved soil. The porosity of samples improved using
C+PFA+GGBS and C+B also decreases with increase in % of
additives, resulting to increase in UCS as shown in Figure 3.0,
however, the reduction in density and increase in UCS shown
in Figure 4.0 again, is due to predominance of % and type of
additive on strength over porosity and density.
Figure 3.0: Variation of unconfined compressive strength and porosity with % of binder
Figure 4.0: Variation of unconfined compressive strength and density with % of binder
International Journal of Applied Engineering Research ISSN 0973-4562 Volume 13, Number 10 (2018) pp. 8684-8694
© Research India Publications. http://www.ripublication.com
8690
Hydraulic conductivity changes with binder inclusion
The coefficient of permeability 𝑘 values obtained from one-
dimensional consolidation test showed a bit of scatter as
expected however, some important trends were observed. The
results plotted in Figure 5.0 and 6.0 show the variation
hydraulic conductivity with degree of saturation of the
improved soil materials at different binder percentages after 7
and 28 days. Figure 5.0 shows that the addition of 6% - 16%
drops the degree of saturation of the improved samples below
degree of saturation line of the unimproved soil due to
hydration reaction of cement and water, resulting to reduction
in hydraulic conductivity. A reduction in % of cement to 3%,
2% and 5.33% and inclusion of equal amount of PFA and
PFA+GGBS also reduces the degree of saturation and
hydraulic conductivity of the improved soil at the early stage of
hydration process.
Figure 5.0: Variation of hydraulic conductivity and degree of saturation with % of binder
Figure 6.0: Variation of hydraulic conductivity and degree of saturation with % of binder
International Journal of Applied Engineering Research ISSN 0973-4562 Volume 13, Number 10 (2018) pp. 8684-8694
© Research India Publications. http://www.ripublication.com
8691
The permeability and compressibility of stabilized soil is also
expected to vary with curing time due to the continuous binder-
soil reaction that occurs because of cement hydration (Åhnberg
2003). Figure 7.0 also shows that hydraulic conductivity
decreases with reduction in cement content and inclusion of
PFA and GGBS contents in the different combinations of
additives after 28days due to reduction in porosity of the
improved soils as % of additive increases as shown in Figure
7.0. Soil matrix consists of pores of numerous different sizes,
and the pores-fill performance of these additives differs and this
causes the variation in porosity of the improved soil across the
different additives and combinations as shown in Figure 7.0.
Figure 7.0: Variation of hydraulic conductivity and porosity with % of binder after 7 and 28 days.
The ease by which water flows through soil is highly dependent
on porosity and it is evident that reduction in porosity
accompanied by reduction in hydraulic conductivity of the
improved soil is because of decrease in distances between
individual soils particles due to bonding. The dependency of
coefficient of hydraulic conductivity of soils on porosity has
been explained using existing empirical relations as shown in
Equations 1.0, (Slichter, (1899), Kozeny (1927)). Equations 1.0
empirically shows the direct proportionality of coefficient of
permeability (hydraulic conductivity) on porosity (n) and pore
radius (r).
𝑘 = 𝑛𝑟2
8 =
n3
aAV2 Eq. 1.0
From Figure 7.0, it is evident that the inclusion of GGBS and
Bentonite causes a smooth reduction in porosity, hence,
decrease in permeability due to consistent fineness and particle
shape of the GGBS powder, and hence, increase in surface area.
Equation 1.0 shows that permeability coefficient is directly
dependent on porosity and inversely dependent on surface area
of the particles per unit volume of porous matrix (Av), where
the parameter (a) is an empirical term and depends on porosity.
This study has shown that hydraulic conductivity of the
improved soil depends on porosity, % of additives, type and
combination of additives as shown in Figure 8.0 and Figure 9.0.
International Journal of Applied Engineering Research ISSN 0973-4562 Volume 13, Number 10 (2018) pp. 8684-8694
© Research India Publications. http://www.ripublication.com
8692
Figure 8.0: Variation of hydraulic conductivity with porosity
Figure 9.0: Variation of hydraulic conductivity with % of binder
The porosity in turn depends on the type and % of additive.
Therefore, this study has defined the functional relationships
between hydraulic conductivity and additive type based on the
% of additives and combinations considered in this study as
presented in Table 4.0. The values of the coefficients of
determination defines how the functions explain the variability
of the response data around its mean.
0
5E-11
1E-10
1.5E-10
2E-10
2.5E-10
3E-10
3.5E-10
4E-10
4.5E-10
5E-10
30 35 40 45 50
Hyd
rau
lic C
on
du
ctiv
ity(
m/s
)
Porosity (%)
Soil-Cem Soil-Cem/PFA Soil-Cem/PFA/GGBS Soil-Cem/Bentonite
0
5E-11
1E-10
1.5E-10
2E-10
2.5E-10
3E-10
3.5E-10
4E-10
4.5E-10
5E-10
0 5 10 15 20
Hyd
rau
lic C
on
du
ctiv
ity
(m/s
)
% of additive
Soil-Cem Soil-Cem/PFA Soil-Cem/PFA/GGBS Soil-Cem/Bentonite
International Journal of Applied Engineering Research ISSN 0973-4562 Volume 13, Number 10 (2018) pp. 8684-8694
© Research India Publications. http://www.ripublication.com
8693
Table 4.0 Functional relationship between hydraulic conductivity and percentage of additive
Function
Mixed soil type
Soil-Cem Soil-Cem/PFA Soil-Cem/PFA/GGBS Soil-Cem/Bentonite
Coefficient of Determination, R2
Linear 0.8285 0.8417 0.9470 0.9297
Exponential 0.8792 0.8942 0.8577 0.9398
Polynomial 0.9487 0.982 0.9476 0.9454
CONCLUSION
This study has considered the effect of Cement and
combinations of cement with materials such as PFA, GGBS
and Bentonite on the strength and hydraulic conductivity of a
fine-grained soil, and the following conclusions have been
drawn.
The strength increase and reduction in hydraulic
conductivity (permeability) of an improved fine-
grained soil depend on the type and amount of additives
and not solely on changes in the physical properties of
the investigated soil.
The combination of Bentonite and Cement, mixed with
fine-grained soil produces an improved soil with
enhanced permeability compared to other additive
combinations due to the hydrophilic property of
bentonite.
Small percentages of the investigated additives and
combinations (<6%) have no significant effect on the
permeability of the improved soil at early age (𝑘 after
7 days of curing).
The least permeability was achieved with 8C+8B
combination but additive content and combinations of
16%C and 5.33C+5.33PFA+5.33GGBS also reduced
the permeability of the fine-grained soil.
List of abbreviations symbols
BS - British Standard
B - Bentonite
C - Cement
CASH - Calcium Aluminate Silicate Hydrate
CSH - Calcium Silicate Hydrate
GGBS - Ground Granulated Blast Slag
PFA - Pulverised Fly Ash
UCS - Unconfined Compressive Strength
k - Hydraulic conductivity
REFERENCES
[1] Abbey, S.J, Ngambi, S., and Ganjian, E. (2017)
‘Development of Strength Models for Prediction of
Unconfined Compressive Strength of Cement/By-
product Material Improved Soils.’ Geotechnical Testing
Journal, Vol. 40, No. 6, pp. 928-935.
doi.org/10.1520/GTJ20160138. ISSN 0149-6115
[2] Abbey, S.J., Ngambi, S., Coakley, E. (2016) ‘Effect of
Cement and by-product material inclusion on plasticity
of deep mixing improved soils’. International Journal of
Civil Engineering and Technology, 7 (5), pp. 265-274.
[3] Abbey, S.J., Ngambi, S., Olubanwo, A.O. (2017) ‘Effect
of overlap distance and chord angle on performance of
overlapping soil-cement columns’. International Journal
of Civil Engineering and Technology, 8 (5), pp. 627-
637.
[4] Abbey, S.J., Ngambi, S., Ngekpe, B.E. (2015)
‘Understanding the performance of deep mixing
improved soils - A Review’ International Journal of
Civil Engineering and Technology, 6 (3), pp. 97-117.
[5] Ali, D.B, Kamarudin, A. and Nazri, A. (2012) ‘Initial
Settlement of Mat Foundation on Group of Cement
Columns in Peat –Numerical Analysis’. Journal of
Geotechnical and Geo-environmental Engineering 17
2243-2253.
[6] Axelsson, K., Johansson, S. E., and Andersson, R.
(2002). ‘Stabilization of Organic Soils by Cement and
Pozzolanic Reactions: Feasibility Study’. Report 3,
Swedish Deep Stabilization Research Center,
Linkoping, Sweden, 51 pages.
[7] Eyo, E.U., NgAmbi, S., Abbey, S.J. (2017)
‘Investigative modelling of behaviour of expansive soils
improved using soil mixing technique’. International
Journal of Applied Engineering Research, 12 (13), pp.
3828-3836.
[8] Abdulhussein Saeed, K., Anuar Kassim, K., and Nur, H.
(2014) 'Physicochemical Characterization of Cement
Treated Kaolin Clay'. Građevinar 66 (06.), 513-521.
[9] Åhnberg, H. (2006) Strength of Stabilised Soil-A
Laboratory Study on Clays and Organic Soils Stabilised
with Different Types of Binder. [online] Doctorate
thesis or dissertation: Lund University.
International Journal of Applied Engineering Research ISSN 0973-4562 Volume 13, Number 10 (2018) pp. 8684-8694
© Research India Publications. http://www.ripublication.com
8694
[10] Åhnberg, H. (ed.) (2003) Grouting and Ground
Treatment. 'Measured Permeabilities in Stabilized
Swedish Soils': ASCE.
[11] Barnard, L., Bone, B., and Hills, C. (2003) Guidance on
the use of Stabilisation/Solidification for the Treatment
of Contaminated Soil. Bristol, UK: R&D Technical
Report P5-064/TR, Environment Agency.
[12] Bruce, D. (2001) 'Practitioner's Guide to the Deep
Mixing Method'. Ground Improvement 5 (3), 95-100.
[13] Bullock, A. (ed.) (2007). 'Innovative Uses of Organo-
Philic Clays for Remediation of Soils, Sediments and
Groundwater': WM Symposia, 1628 E. Southern
Avenue, Suite 9-332, Tempe, AZ 85282 (United States).
[14] Chao, Y., Songyu, L., and Yongfeng, D. (2015)
'Experimental Research for the Application of Mining
Waste in the Trench Cutting Remixing Deep Wall
Method'. Advances in Materials Science and
Engineering 2015.
[15] Consoli, N.C., Winter, D., Rilho, A.S, Festugato, L. and
Teixeira, B.S. (2015) “A testing procedure for predicting
strength in artificially cemented soft soils”, Journal of
Engineering Geology, 195 pp. 327- 334.
[16] Eurosoilstab (2002) Development of Design and
Construction Methods to Stabilize Soft Organic Soils:
Design Guide for Soft Soil Stabilization. Project No.
BE-96-3177 edn: European Commission, Industrial and
Materials Technologies Programme (Rite-EuRam III).
[17] Higgins, D. (2005) 'Soil Stabilisation with Ground
Granulated Blastfurnace Slag'. UK Cementitious Slag
Makers Association (CSMA).
[18] Holm, G., (2003) “State of practice in dry deep mixing
methods,” in Proceedings of the 3rd International
Conference on Grouting and Ground Treatment, pp.
145–163, ASCE, New Orleans, La, USA, February.
[19] Jawad, I. T., Taha, M. R., Majeed, Z. H., and Khan, T.
A. (2014) 'Soil Stabilization using Lime: Advantages,
Disadvantages and Proposing a Potential Alternative'.
Research Journal of Applied Sciences, Engineering and
Technology 8 (4), 510-520.
[20] Keramatikerman, M., Chegenizadeh, A., and Nikraz, H.
(2016) ‘Effect of GGBFS and Lime Binders on the
Engineering Properties of Clay’. Applied Clay Science
[online] 132–133, 722–730. available from
<http://dx.doi.org/10.1016/j.clay.2016.08.029
[21] Kozeny, J. (1927), Uber kapillare Leitung der Wasser
in Boden, Sitzungsber. Akad. Wiss. Wien, 136, 271–306.
[22] Makusa, G. P. (2012) Soil Stabilization Methods and
Materials. [online] PhD thesis or dissertation. Luleå,
Sweden: Luleå University of Technology.
[23] Mousavi, S. E. and Wong, L. S. (2016) 'Permeability
Characteristics of Compacted and Stabilized Clay with
Cement, Peat Ash and Silica Sand'. Civil Engineering
Infrastructures Journal 49 (1), 149-164.
[24] Oana, C., (2016) “Soil Improvement by Mixing
Techniques and Performances” Energy Procedia 85, pp.
85-92.
[25] Slichter, C.S. 1899. Theoretical investigations of the
motion of ground waters. U.S. Geological Survey 19th
Annual Report, Part 2.
[26] Talfirouz, D. (2013) The use of Granulated Blast-
Furnace Slag, Steel Slag and Fly Ash in Cement-
Bentonite Slurry Wall Construction. [online] thesis or
dissertation: MIDDLE EAST TECHNICAL
UNIVERSITY.
[27] Terashi, M. (2009) ‘Current Practice and Future
Perspective of Quality Assurance and Quality Control
for Deep-Mixed Ground’. Okinawa Deep Mixing
Symposium.
[28] Wang, F., Wang, H. and Al-Tabbaa, A. (2015), ‘Time-
dependent Performance of Soil Mix Technology
Stabilised/Solidified Contaminated Site Soils’ Journal of
Hazardous Materials, 285, 503–508.
[29] Yi, Y., Liska, M., and Al-Tabbaa, A. (2013) 'Properties
of Two Model Soils Stabilized with Different Blends
and Contents of GGBS, MgO, Lime, and PC'. Journal of
Materials in Civil Engineering 26 (2), 267-274.