Soil-cement is frequently used as a construction material for pipe bedding, slope protection, and road construction as a sub-base layer reinforcing and protecting the subgrade. It has good compressive and shear strength, but is brittle and has low tensile strength, so it is prone to forming cracks. Lime can be used to treat soils to varying degrees, depending upon the objective. The least amount of treatment is used to dry and temporarily modify soils. Such treatment produces a working platform for construction or temporary roads. A greater degree of treatment supported by testing, design, and proper construction techniques--produces permanent structural stabilization of soils.

1. Presented By
Aniket Pateriya
SEMINAR ON
Overview of Soil Stabilization
:Cement / Lime
Guided By
Dr. Suneet Kaur

2. CONTENTS
 INTRODUCTION
SOIL-CEMENT STABILIZATION
 SOIL-LIME STABILIZATION
CASE STUDY
REFERENCES

3.  Soil-Cement
 Soil-Lime
 Least amount of treatment
 Greater degree of treatment
INTRODUCTION

4.  Soil-Cement stabilization:
• Laboratory tests
• Construction method :
 Pulverising the soil
 Shaping the sub grade and scarifying the soil
 Adding and mixing cement
 Adding the mixing water
 Compacting
 Finishing
 Curing
 Adding wearing surfacing

5. • Cement stabilizes soil in two ways,
 Reduces soil plasticity (In Soil having high amount of clay in general).
 Cementation
• The strength of soil-cement increases with age

6.  Importance factor affecting strength of soil-cement matrix are
as follow:
 Nature of soil: Effective when clay soil LL is less than 45% and PI is less than about 25%.
 Cement content range: Granular soil (3 to 10%) and clay soil (7 to 16%).
 Moisture content of new matrix: Same as OMC for achieve maximum dry density.
Maximum strength is achieved at moisture content slightly less than this.
 Admixtures: Either to reduce cement content or in order to make soil suitable for stability,
Etc.

7. Advantages:
• Stiffness: Distribute loads over a wider area and rutting is relatively simple and less
expensive to correct.
• Great Strength: Reserve strength also resists cyclic cold, rain and spring-thaw damage.
• Superior Performance: Good service at low maintenance costs
• Reduces the occurrence of fatigue cracking.
• It is designed material whose properties and production can be very carefully tested and
controlled.
• It is durable material
• Due to fractural strength it offend classified as semi-rigid material.

8. Disadvantages:
 Cement is costly material.
 As cement hydrated volumetric change may take place give shrinkage crack.

9.  Soil-Lime stabilization:
• Fine-grained clay soils (with a minimum of 25 percent passing the #200 sieve (75μm)
and a Plasticity Index greater than 10) are considered to be good candidates for
stabilization.
• Subgrade stabilization requires adding 3 to 6 % lime by weight of the dry soil.

10.  The Chemistry of Lime Treatment:
 Drying:
• Chemical reaction
• Subsequent reactions reduce the soil’s moisture holding capacity.
 Modification:
• Flocculation and agglomeration“,
• Lime content of 3 to 18% by volume are used to reduce plasticity of clay.
 Pozzolanic or cementation reaction: Stable calcium silicate and aluminates
form
 Carbonation:
• Lime react with carbon dioxide and form calcium carbonate it increases
the
• Excessive lime does not produce beneficial results.

11.  Importance Factor Affecting Strength of Soil-lime Matrix :
• Compaction Characteristic:
 The maximum density decreases with curing time and lime content.
 The optimum moisture content, Increase with curing time and lime content.
• Plasticity and workability:
 Plasticity index decreases and shrinkage limit increases.
 Soil with high plastic index initially required high lime content.
• Volume change: significant reduction in swell potential and swell pressure occur.
• Strength:
 Lime increase the
 Minor changes in angle of internal friction.

12. Advantages:
 Lime stabilization improved the strength, stiffness and durability of fine-grained soil,
Effective in heavy clay soils.
 When use in clay, lower the LL and PI of soil.
 It produces maximum density under higher optimum moisture content then in untreated soil.
 Lime stabilization also use for highly unstable plastic and swelling clay.
Disadvantages:
This mainly suitable for clayey coil, Soil contain more than 2% organic content may not
suitable.

13.  Case Study :
In-Situ Stabilization of Road Base Using Cement
trial section along the North-South Expressway in Malaysia
Design parameters adopted in the cement stabilized base (CTB) design is as follows:
 Design water content within 4.5+0.5% of the dry mass of aggregate and cement.
 Design cement content was 3.5% (by mass of the dry aggregate). The cement content was
decided based on the targeted compressive strength (4 MPa to 8 MPa).
 A minimum effective stiffness modulus of 1000MPa to be achieved after 28 days of curing.
 The average 7-days compressive strength determined from a group of 5 cubes of the CTB
road-base shall be between 4 and 8MPa.
 The average in-situ wet density shall not be less than 94% of the average wet density of the
corresponding group of 5 cubes.

14. Age
at
test (days)
In-situ compressive strength (MPa)
from core samples
In-situ compressive
strength (MPa) from
cube specimens
1 - 3
3 - 5.5
4 4.5 -
7 - 6.0
8 6.0 -
29 7.5 -
Table : Compressive strength of the CTB layer
[Source: G. W. K. Chai et al (2005)]

15. Falling Weight Deflectometer (FWD) was adopted to determine the in-situ stiffness of the
cement stabilized road base material.
Figure : Falling weight deflectometer (FWD)
[Source: researchgate.net]

16. • Normalized deflection readings were measured by geophones at distances (0, 300mm,
600mm, 900mm, 1200mm, 1500mm and 2100mm) from the center of the loading
plate
• FWD test:
 Center deflection reading of 900 microns at 85 percentile value.
 For tests performed on the CTB, center deflection value at 85 percentiles for the 3
and 7 days are 500 micron and 400 microns, respectively.
 Center deflection at 85 percentile gives a value of 300 micron for 28 days cure.
Figure : FWD center deflection profiles before and after cement stabilization
A: (3 and 7 days); B: (28 days)
[Source: G. W. K. Chai et al (2005)]

17. Test stages Effective stiffness modulus (MPa)
at 85 percentile values
Pavement Layers CTB Road base
Granular Road base
Before Recycling
- 280
CTB after 3 days 700 -
CTB after 7 days 1150 -
Asphalt Surface after
28 days
1350 -
Table : Effective stiffness modulus of the CTB layer
[Source: G. W. K. Chai et al (2005)]

18. Figure : Compressive strength and deflection D1 relationship from FWD.
[Source: G. W. K. Chai et al (2005)]

19. Figure : Stiffness modulus and compressive strength relationship from field test
[Source: G. W. K. Chai et al (2005)]

20. Statistical regression analyses have been performed to establish the empirical relationship
• The relationship for compressive strength and FWD deflection is illustrated in following
Equation:
Su = 7.4543 ln(D1) + 51.002
Where, Su is compressive strength of CTB (MPa), and D1 is the reading from FWD
deflection sensor (micron).
• The Relation stiffness modulus and compressive strength of CTB is illustrated in following
Equation:
E = 381 Su 0.6047
Where, E is the back-calculated stiffness modulus (MPa)

21. Conclusions of case study
• A pavement section of 100m in length on the Southbound Carriageway of the North-
South Expressway (West Malaysia) has been rehabilitated by strengthening the
existing granular road base using cement stabilization.
• The deflections were observed to decrease between 3 and 7 days due to curing of the
CTB base. The use of cement stabilized base leads to a significant improvement in the
structural capacity of the pavement.
• An empirical relationship between the in situ compressive strength and the deflection
of the CTB layer has been proposed.
• An empirical relationship between the stiffness modulus and the in-situ compressive
strength of the CTB.
• FWD test also used to demonstrate that the required compressive strength and stiffness
modulus of the CTB had been achieved on site
• These two engineering relationships and actual FED results can be useful for the
monitoring the performance of the CTB layer when stabilization is in progress for
actual work.
• The expected design life, based on the actual in-situ properties of the pavement, could
be determined in greater confidence.

22. REFERENCES
 Bikash Chandra Chattopadhyay, Joyanta Maity. “Foundation Engineering” ;(Text
Book), PHI, New Delhi.
 Dastidar, A.G. (1985). “Treatment of weak soil- An Indian perspective” -
Geotechnical Engineering, Vol. 1.
 G. W. K. Chai, E. Y. N. Oh and A. S. Balasubramaniam. (2014). “In-Situ Stabilization
of Road Base Using Cement - A Case Study in Malaysia”, School of Engineering,
Griffith University, Australia.
 Lamb, T.W. (1962). “Soil Stabilization in foundation engineering”. - G. A. Leonard
(Ed.) McGraw-Hill, New York.
 NLA (National Lime Association). (1985). “Lime Stabilization Construction
Manual”; Bulletin 326, Arlington, VA.
 Shashi Gulhati, Manoj Datta. “Geotechnical Engineering” ;(Text Book), McGraw-
Hill, New Delhi.

23. Thank
You