ῐ
J. Jpn. Soc. Soil Phys.
῏῍ῌῐῑ῎
No. +*-, p. -+ῌ-2 ῍,**0῎

E#ect of Ordinary Portland-Cement on Properties ofClayey Soil in Mie Prefecture
Md. Zakaria HOSSAIN*, Hajime NARIOKA* and Toshinori SAKAI** Graduate School of Bioresources, Mie University, +/11 Kurima Machiya-cho,Tsu-shi, Mie /+.ῌ2/*1, Japan
Abstract
The clayey soils of Kameyama Mountain in Mie prefecture were studied experimentally in thelaboratory with the idea of improving some of its engineering properties by using a very small
amount of ordinary Portland cement. Laboratory tests on shear strength, compressive strength,
consistency limits, compaction and speciﬁc gravity of soil were carried out with cement content
of *ῌ, *.,ῌ, *..ῌ and *.0ῌ by weight. It was observed that the cohesion which is a major
component regarding the strength of soil was increased with the increase in the amount of cement
and angle of internal friction at higher cement content was decreased. Compressive tests under
two di#erent room temperatures showed the compressive strength to be increased with theincrease in the quantity of cement depending upon the temperature providing on it. Plasticity
index, a measure of soil plasticity was found to decrease with the increase in the percentage of
cement mixed with it. A close observation of results plotted in the plasticity chart also noticed
that the addition of cement reduced the compressibility, dry strength and toughness of soil whilst
increasing the volume change ratio and speciﬁc gravity of soil.
Key words : soil-cement, shear strength, compressive strength, plasticity chart, compaction curve+.

Introduction

It is evident that the natural soils possessvery complex properties and vary widely intheir behavior depending on the in-situ conditions. Therefore, soil of a particular location
may not be fully useful as per the expectationof the users owing to its variable characteristics. To overcome these problems, the users
may have the following three options such as+) using the in-situ soil in its existing state
accepting all its limitations, ,) using a better
material by replacing the in-situ non-ideal soil
and -) using some techniques that modify thein-situ soil to make it more suitable for proper
applications. There are a lot of methods suchas mechanical, chemical, thermal, electrical andphysical, etc used to improve the properties ofsoils (ACI, +33* ; Wilhelmsson, +331). However,none of the methods is ever unique in morethan a limited number of soils due to its wider
variability and complexity (Awal and Mamun,+332).
The improvement of soil properties using
cement began nearly a half century ago withthe concept of the process of deductive reasoning (Mitchell, +310). It is found from the previous studies that the uses of cement to improve
the soil properties is somewhat unique because
the cement, major component of which is calcium oxide, produce a conditioned material withsoil by interacting with the water content ofsoil particles. Therefore, the soil-cement produced by mixing cement with soil is not a simple mixture of soil and cement but a uniquecomposite material (Ahuja and Swartzendruber,+31, ; Boswell, ,***). Because of its chemical
make-up, cement is able to provide beneﬁts for

῏



32

both granular and ﬁne graded soils. By addition of water to cement, cementitious reaction
immediately begins and thereby, as the products, it forms quickly CaOῌSiO,ῌH,O andCaOῌAl,O-ῌH,O. These products act as a glue
to bind material together, reduce moisture ﬂow
channels, and improve gradation and stabilityof soils (Prusinski and Bhattachaja, +332). Literature review indicates that to date, percentage of cement used to improve the properties
of soil is 0 to +.῍ or more. The idea of using avery small amount of cement proposed in thispaper is a newer one and important for thesake of cost saving in soil-cement construction
works.
In this paper, an investigation was carriedout in the laboratory to improve some engineering properties of clayey soils of Kameyama
city in Mie Prefecture based on known properties of soil, cement and their combination.
The e#ect of variable percentage of cement on
the shear stress-shear displacement relationships, shear stress-normal stress relationships,
cohesion, angle of internal friction, consistency
limits, plasticity charts, compaction curves, optimum water content, dry unit weight, specificgravity and compressive strengths of soil were
investigated with di#erent room temperatures.
,.

Materials and methods

The soil samples were collected from theKameyama Mountain in Mie prefecture, andtested at the laboratory. The particle size distribution curve is shown in Fig. +. The particle
size distribution curve of the soil indicates that,nearly, --῍ of the soil is clay, --῍ is silt, +.῍
is ﬁne sand, +.῍ is medium sand, and 0῍ iscoarse sand, which means that more than 00῍
percent of the soil is in the clay and silt fraction. The other properties of the soil used inthese tests are depicted in Table +. According
to the uniﬁed classiﬁcation system, the soil usedin this research is classiﬁed as CH.
Any type of cement can be used for improving the engineering properties of soil. Ordinary Portland cement (Type I), which is the+*-,**0

Fig. +

Particle size distribution curve of soil.

Table +

Properties of soilParameters

Properties

Dry bulk density (rd)Optimum water content (Wopt)
Speciﬁc gravity (rs)Cohesion (c)Angle of internal friction (f)+4/- g.cm,*4/῍,41*++/14. kPa-,42Sand, 1/ mm
Silt, /ῌ1/ mm
Clay, / mm

-.῍
--῍
--῍

Liquid limit
Plastic limit
Plasticity index

0+4*῍
,142῍
--4,

most common for construction works and alsoavailable widely in the local market, is used inthis investigation. The detailed properties ofthis cement can be found elsewhere (JSCE, ,**-).
The soil sample was air-dried in room temperature of nearly ,/ and humidity of about .*῍for +* days, and, then, grinded it to ease thesieving process. For removing unnecessary elements from the soil and for reducing variability of the particle sizes of the soil, it was sieved
by Japanese Industrial Standard (JIS) Sieve
No. . (. mm opening), and, then, the required
amount of soil was taken, and the desired quantity of cement was mixed properly. The calculated amount of water to be necessary to obtain a water-cement ratio of *./, and optimum
water content of soil was taken and added gen-῏῎ : E#ect of Ordinary Portland-Cement on Properties of Clayey Soil in Mie Prefecture

tly to the dry mix, and, ﬁnally, the components
were mixed thoroughly. The mixing process
was done manually in a bowl with a scoop. In
each batch, nearly - kg soil was required forwhich manual mixing was considered to beenough. Dry mixing was carried out in such a
way of both pulverization and mixing at thesame time with physical observation by naked
eye. The procedure involved several passes ofscoop through dry mix to ensure an even distribution of cement in the mixture. Nearly +* to+/ minutes were required to obtain a homogeneous soil-cement mixer. Water content up to
the optimum one was added, gradually, to themix while continuously stirred. As mentioned
above, additional water calculated as water tocement ration of *./ beyond the optimum watercontent was added to allow for the hydration of
cement. A careful inspection revealed that thecolor of the soil-cement mixer, ﬁnally, changed
to slightly light ash whereas the initial color of
the soil was light brown. However, this changeof color was not well profound because theamount of added cement was very small.
The index property testing included ten water content, four liquid and plastic limit tests,
four particle size analyses using sieve and hydrometer tests, as well as three speciﬁc gravity
tests. These tests were performed according to
ASTM test procedures (ASTM, +333), and compaction tests were performed according to themodiﬁed standard proctor method, ASTM D+//1ῌ3+.
For the unconﬁned compressive strength(UCS) test, specimens were manually compacted in a +,./ cm height by 0.* cm diameter
mould. The specimens were compacted inthree layers using a /.3 mm diameter handrammer with rammer weight of + kg and falling height of -** mm. Each layer was compacted by ,* blows. All the samples were moist
cured for 1 days, and, then, the samples were
tested for unconﬁned compressive strength ata loading rate of *.+ mm per minute. It is notedthat the temperature of Mie Prefecture varies
from nearly ,ῌ+0῍ during winter season (from33

November to March) and +1ῌ-.῍ during summer season (from April to October). The variation of temperature that occurs naturally due
to the change of seasons, is necessary to be investigated its e#ect on behavior of soil. In
order to assess the e#ect of temperature in Mie
Prefecture, Japan, curing was done in 3῍ (considering average temperature of winter season)
and ,/῍ (considering average temperature ofsummer season) for separate set of samples with
di#erent cement contents (*ῌ, *.,ῌ, *..ῌ and*.0ῌ). Average strength values were calculated for each set of the four samples. These tests
were carried out in accordance of ASTM standards.
For shear tests, specimens of 0* mm diameterand ,* mm height were prepared in cutter-ringplacing into the mould of standard proctor test.
Compaction was done in accordance of ASTM
D +//1ῌ3+. After one week moist curing, thespecimens were tested by direct shear test apparatus with shear speed of *.+ mm/min. All
the shear tests were carried out under constantnormal stress of +** kN/m,, ,** kN/m,, -** kN/m, and .** kN/m, for each soil-cement sample.
Vertical displacement, shear stress and shear
displacement were measured at intervals of -*seconds for each normal stress condition. These
tests were also carried out in accordance of
ASTM standards.
It is noted here that the shear and compressive strengths of the specimens depend on thewater content, dry density after compaction as
well as degree of compaction. In order to avoid
these discrepancies, all the specimens were prepared with optimum water content and compaction was done in accordance with standard
modiﬁed proctor test.
-.

Results and discussion

E#ect on consistency limits and plasticity index
The liquid limit, plastic limit and plasticity
index of soil with di#erent cement content areplotted in Fig. , showing that the liquid limit
decreases upon addition of cement with soil.
-. +ΐῐ῎῔῕ῑ ῒ +*- ῏ ῌ,**0῍

34Plastic limits, on the other hand, does not decrease with the addition of cement. Therefore,
the plasticity index is to decrease with theincrease in the percentage of cement content.
The decrease in the plasticity index might bedue to the reduction of clay particles with addition of cement. This is expected because of theliming e#ect of cement, which increases the silt
and ﬁne sand content by cementing the ﬁner
particles into bigger ones. From the plasticity
chart (Fig. -), it is shown that the addition ofpercentage of cement with soil tends to reducethe compressibility, dry strength and toughness of soil as well as tends to increase thevolume change ratio of soil.
From Fig. ., it is clear that, upon addition of
cement, the pore spaces between the soil particles are ﬁlled up by the cement particle, and thespeciﬁc gravity does increase with the increaseof cement content. At *.0*ῌ cement content,

Fig. ,

Variation of consistency limits of soilcement with di#erent cement content.

Fig. -

the speciﬁc gravity is about ,.1+1.
-. , E#ect on dry unit weight and optimum
water content
From Figs. / and 0, it is found that, for thesame energy supplied, the maximum dry bulk
density does decrease with the increase of cement content, and, at *.0*ῌ cement content, thedry bulk density becomes about +./3 g/cm-. On
the other hand, the optimum water content
increases with the increase of cement content,
and, at *.0*ῌ cement content, the optimum
water content becomes about ,+.3ῌ.
-. - E#ect on shear stress-displacement relationships
The shear behavior, a principal engineering
property of soil-cement, is demonstrated using
the shear stress-displacement curves. The shear
stress and shear displacement relationships ofcontrolled specimens (*ῌ cement) with variable normal stress are depicted in Fig. 1. It

Fig. .

Variation of speciﬁc gravity of soil-cementwith di#erent cement content.

Plasticity chart of soil-cement with di#erent cement content.
(A-line is based on Ipῌ*.1- (wL-,*) and B-line is based on wLῌ/*)῍ῌ : E#ect of Ordinary Portland-Cement on Properties of Clayey Soil in Mie Prefecture

should be pointed out here that all the specimens used in shear tests were prepared withthe optimum water content obtained throughthe standard modiﬁed proctor test as reported
in section -.,. The optimum water contents
were obtained as ,*./, ,+.*, ,+./ and ,,.,ῌ for
specimens containing cement of *.*ῌ, *.,ῌ,*..ῌ and *.0ῌ, respectively. It is observed thatthe shear stress increases with the increase of

Fig. /

Fig. 0Fig. 135

displacement, naturally, but, due to the di#erent normal stress, the increment rate varies
depending on the amount of cement mixing.
Figs. 2 to +* show the variation of shear stresswith displacement under di#erent normal stressand cement content. For all cement contents,
the shear stresses are increased as compared tothe *.*ῌ soil-cement. The variation between
shear stress and displacement gets smoother

Compaction curves of soil-cement with di#erent cement content.
(Z.A.V.C. means zero air void curve)

Variation of Wopt and unit weight of soil-cement with di#erent cement content.

Shear stress vs. shear displacement (*ῌsoilcement).

Fig. 2

Shear stress vs. shear displacement (*.,ῌ
soil-cement).



36

with more cement content under all types ofnormal stress. For every curve, there is a peakor ultimate stress which is greater than the
failure stress.
-. . E#ect on shear strength
The shear strength of a soil is its maximum
resistance to shear stresses before the failure.
It is a most important factor to investigate because it controls the stability of a soil mass under loads. Fig. ++ shows the variation of shear
strength due to the variation of normal stressof soil-cement with di#erent cement content. It
shows that owing to the increase in normal

Fig. 3

Shear stress vs. shear displacement (*..ῌ
soil-cement).

Fig. +*

Shear stress vs. shear displacement (*.0ῌ
soil-cement).

Fig. +++*-,**0stress the shear strength also increases. Under+** kN/m, normal stress, the shear strength for*.0ῌ cement content is highest (about -/* kN/m,) than those for other cement contents (*ῌ,*.,*ῌ, *..*ῌ), and for ,** kN/m, normal stress,
the shear strength for all cement content except *ῌ are more or less same (about -2* kN/m,), but, for *ῌ cement content the shear
strength is about +3* kN/m,. For -** kN/m,,some di#erent trends are shown that shear
strength for *.,*ῌ is the highest value (about/** kN/m,) than those for other cement contents and this same trend is also shown for .**kN/m, normal stress where the highest shear
strength is about 0** kN/m, at *.,*ῌ cement
content. From the straight lines drawn in Fig.
++, the following equations can be obtained.
t*.*ῌ*.0s*.*ῌ+/1..

ῌ

t*.,ῌ+.+s*.,ῌ+01.0

῍t*..ῌ*.2s*..ῌ,.2.-῎

t*.0ῌ*.-s*.0ῌ-+0./

῏

where, t is the shear strength of soil-cement
under direct shear test in kN/m, and s is theapplied normal stress (overburden pressure) in
kN/m,. Therefore, the angles of internal friction of the soil-cement are calculated as -,.2*,.2.+*, -3..* and ++.-* ; and cohesion are obtained
as +/1.., +01.0, ,.2.- and -+0./ kN/m, for *ῌ,*.,ῌ, *..ῌ and *.0ῌ soil-cement, respectively.
The e#ect of di#erent amount of cement contents on cohesion and angle of internal friction
is shown in Fig. +,. It is found that there is nota signiﬁcant improvement of cohesion up to

Shear stress vs. normal stress of soil-cement with di#erent cement content.

῏῎ : E#ect of Ordinary Portland-Cement on Properties of Clayey Soil in Mie Prefecture*.,ῌ cement content, but, when cement content
is higher than *.,ῌ, the cohesion starts to increase to a great deal even up to -/* kN/m, at*.0*ῌ cement content. The angle of internal
friction also slowly increases with the increaseof cement content up to *.,ῌ, but, when cement content is higher than *.,ῌ, then it starts
to decrease, and the rate of decreasing getshigher with the higher cement content, and at*.0*ῌ cement content, the angle of internal friction is about ++.- degree. This might be due tothe anti-synergetic action between cohesion andinternal friction. However, our understandingon this phenomenon is also rudimentary.
-. / E#ect on unconﬁned compressive strengthwith two curing temperatures
Test results on the unconﬁned compressive
strength of the soil-cement with three di#erent
mix proportions are depicted in Fig. +-. In order to obtain the e#ect of curing temperatureon the test samples, two types of specimens
were cured in room temperature of 3῍ and,/῍ and tested for unconﬁned compressive
strength. For both samples, it is observed thatthe compressive strength increases with theFig. +,

Fig. +-

Variation of c and f of soil-cement with
di#erent cement content.

Variation of compressive strength of soilcement with di#erent cement content.

37

increase of cement content, but, the increasingrate is higher for specimens cured at ,/῍ thanfor specimens cured at 3῍. This is obvious,
because, when the curing temperature is high,quick formation of the calcium silicate and aluminum silicate is occurred, that results in rapid
setting time and harden time. It is also notedthat the increasing rate gets slow for cement
contents above *..*ῌ. This might be the causeof reduction of internal friction with the increase of cement content as can be seen in Fig.
+,. At *.0*ῌ cement content, the compressive
strength is about /** kN/m, for specimens
cured at ,/῍ and -** kN/m, for specimens
cured at 3῍. Here, the plotted compressive
strengths are average values of four samples.
The most important results of this study
depicted in Figs. ++ and +- shows that boththe shear and compressive strengths were improved compared to the controlled specimens.
As expected, there is a fairly consistent trend
in the increase of strengths with the addition ofsmall amount of cement. This might be due tothe cause of ionic action comes from cement,water and soil. Cement releases Caῌῌ ions in
the mixture of soil-cement when added certain
amount of water in it. These ions are attracted
to negative ions comes from clay minerals resulting in clay particles together. The main
source of observed strengths in this case is dueto the formation of C-S and C,S compoundswith the presence of clay minerals that ﬁnallyresult to form C-S,H- in water.
..

Conclusions

A very nominal dosage rate of ordinary Portland cement such as *.,ῌ, *..ῌ and *.0ῌ wasused for improving the engineering propertiesof clayey soils. The test results revealed thatthe addition of small amount of cement not only
increased the cohesion of soil signiﬁcantly but
also improved the compressive strength of soil.
There was a slight decreasing trend in the frictional resistance with the cement content above*..ῌ ; however, overall shear strength was increased with the increase in the amount of ce-6¯3®5 ° +*- ± ²,**0³38

ment. In the present study, it was also revealed
that the maximum shear strength occurred at
the shear displacement of nearly ,ῌ. mm formost of the cases. It was also found that theincrease in the percentage of cement not only
reduced the plasticity index, a measure of soil
plasticity, but also reduced the compressibility,
toughness and dry unit weight of soil. The
small amount of ordinary Portland cement canalso be e#ectively used for improving the volume change ratio and speciﬁc gravity of clayeysoils. It should be pointed out here that theamount of cement was very small and, therefore, the improvement in the shear and compressive strengths were not highly signiﬁcant.
Also, there were some scatters in the strengths
properties owing to the little experimental data.
Further investigations are suggested to study
the strength characteristics and other basic
properties for a wider range of cement mixing.
Nonetheless, the result depicted in this paper isfairly encouraging, especially for improving
the engineering properties of clayey soil.
References
ACI Committee (+33*) : State-of-the-Art Report on

Soil Cement, American Concrete Institute, + :+ῌ,-.
ASTM, D.,*-.3+. (+333) : Annual Book of StandardsSoil and Rock, American Society for Testingand Materials . : 2ῌ,*.
Ahuja, L.R. and Swartzendruber, D. (+31,) : E#ect
of Portland cement on aggregation and hydraulic properties. Proceedings of the Soil Science Society of America, ++. : -/3ῌ-00.
Awal, A.S.M.A. and Mamun, A.A. (+332) : Improvement of Bangkok Clay by Using Ordinary Portland Cement, Proceedings of the International
Symposium on Problematic Soils, Balkema,
Rotterdam, + : 0*-ῌ0*0.
Boswell, W.F. (,***) : Soil Stabilization/Soil Cement
Mark-Lang, Inc.’s Approach, Soil-Cement andOther Construction Practices in GeotechnicalEngineering, ASCE, 3/ : ,0ῌ-/.
JSCE committee, (,**-) : Guideline for Experiment
on Materials of Civil Works, Japan Society of
Civil Engineers, + : +ῌ,..
Mitchell, J.K. (+310) : Fundamentals of Soil Behavior, John Wiley and Sons, Inc. New York.
Prusinski, J.R. and Bhattacharya, S. (+333) : E#ectiveness of Portland Cement and Lime in Stabilizing Clay Soils, Transportation Research
Board, Record No. +0/,, , : +32ῌ,*0.
Wilhelmsson, B. (+331) : Strength properties of cement mortars with lime and dolomite, MIMERrapport : +ῌ+,.

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