daniel siyingwa 12032174 compaction with stabilizer

8/18/2019 Daniel Siyingwa 12032174 Compaction With Stabilizer

1/8

Lab report on Compaction Test with stabilizer

1

THE UNIVERSITY OF ZAMBIA

SCHOOL OF ENGINEERING

DEPARTMENT OF CIVIL AND ENVIRONMENTAL

ENGINEERING

CEE 4511

LAB REPORTON

COMPACTION WITH CEMENT AS STABILIZER

Submitted By: Submitted To:

Siyingwa Daniel J Mr Andrew Phiri

12032174 Department of Civil and

Environmental Engineering

Date Conducted: 3

rd

December 2015

Date due: 10

th

December 2015


2/8


2

Table of Contents

1. TITLE

2. OBJECTIVES

3. APPARATUS REQUIRED

4. THEORY

5. PROCEDURE

6. OBSERVATION AND CALCULATION

7.

RESULT8. DISCUSSION

9. CONCLUSION

10. RECOMMENDATIONS

11. REFERENCES


3/8


3

TITLE: SOIL COMPACTION WITH PORTLAND CEMENT AS THE STABILIZER

OBJECTIVES

To determine the optimum moisture content and maximum dry density for a soil samples

compacted with 5% and 7.5% Portland cement as stabilizer.

To determine the effect of a stabilizer on the Optimum moisture content and Maximum dry

density of a soil sample

To compare the results obtained in compaction without stabilizer with those obtained in

compaction with stabilizer

APPARATUS REQUIRED

1. Cement to act as stabilizer

2.

20 mm B.S. sieve3. Wide metallic surface for kneading of soils

4. Electronic balance with a least accuracy of 0.1g

5. Cylindrical metal mould with an internal diameter =105mm, an effective internal depth of

115mm and a volume of 1000cm2, fitted on a removable baseplate and with a removable

collar of an effective height of about 50mm

6. A metal rammer with a 50mm diameter ramming face and weight of 2.5kg. the rammer has

a drop height of 300mm

7. Palette knife and a straight edge

8. Cylindrical CBR mould having a nominal internal diameter of 152 mmm and height

127mm. the mould is fitted with a detachable baseplate and removable extension9. A metal rammer of 4.5 kg

10. A steel rod

THEORY

Portland cement stabilization is ideally suited for well graded aggregates with a sufficient

amount of fines to effectively fill the available voids space and float the coarse aggregate

particles. Portland cement is defined as a hydraulic cement which is manufactured as

homogeneous product by grinding together Portland cement clinker and calcium sulphate, and

which, at the discretion of the manufacturer, may contain up to 7.5% of mineral addition. The

cements hydrates in the presence of water to form hydrated calcium sulphates.

PROCEDURE

Test procedure for bul k density and moisture content

I. An air dried soil sample was taken and sieved through a 20mm B.S sieve, then of the passed

material, 5kg was measured.

II. 5 % of the mass of Portland cement was then measured and added to the aggregate


4/8


4

III. 300cm3 of water was added to it and mixed thoroughly.

IV. The mold and baseplate were assembled and then weighed to the nearest 1 gram. The mold,

baseplate and collar were all assembled and the moist soil was placed in the mold and

compacted. The soil was put into the mold in three layers, one of an 855g weight at a time,

compacted with 27 free-falling blows of the 2.5kg rammer, making sure the blows were

evenly distributed over the soilV. After compaction, the collar was removed and the excess soil was carefully struck off with

a straight rod

VI. The weight of the mold- baseplate assembly with the soil then measure out and recorded

VII. The soil was then removed from the mold and a small representative sample was collected

and put in the oven to dry for 24hours at 1100 Celsius for moisture content determination

VIII. A 6 % water increment was made to the rest of the soil through the addition of 100cm3 of

water

IX. The procedure was repeated for 4 more times and the values obtained were recorded

X. The whole procedure was repeated with a unused soil sample with a mass of the cement

being 7.5%

OBSERVATIONS AND CALCULATIONS

Table 1: Water Content Determination for 5% cement

Name of test: Compaction Test with Stabilizer

Location of Test: Soil Mechanics Lab

Tested by: Group 1

Mass of soil Sample taken for analysis : 5000gm Date of testing: 9-

Dec-2015

Sample Number 1 2 3 4 5

Can No. 89 28A 57 78 90

Weight of can(g) 7.00 6.00 6.00 7.00 7.00

Weight of can+Wetsoil(g)

19.00 30.30 22.00 42.70 64.10

Weight of can+Dry

soil(g)

18.00 27.70 20.00 37.50 53.59

Weight of dry soil(g) 11.00 21.70 14.00 30.50 46.59

Weight of water(g) 1.00 2.60 2.00 5.20 10.51

Water content (%) 9.09 11.98 14.29 17.05 22.56


5/8


5

Table 2: Dry density determination for 5% cement

Assumed Watercontent (%)

6.00 10.00 14.00 18.00 22.00

Water Content

(%)

9.09 11.98 14.29 17.05 22.56

Weight of

Mould(g)

4627.00 4627.00 4627.00 4627.00 4627.00

Weight of

soil+mould

6493.00 6622.00 6745.00 6710.00 6700.00

Weight of soil in

mould(g)

1866.00 1995.00 2118.00 2083.00 2073.00

Wetdensity,(g/cm3)

1.87 2.00 2.12 2.08 2.07

Dry density

(g/cm3)

1.71 1.78 1.85 1.78 1.69

Table 3: Water content determination for 7.5% cement

Sample Number 1 2 3 4 5

Can No. 95 79 99 19N B4

Weight of can(g) 6.60 6.80 6.90 6.80 6.50

Weight of can+Wet

soil(g)

48.40 45.10 64.10 75.60 82.20

Weight of can+Drysoil(g)

45.50 41.30 56.90 65.70 70.10

Weight of dry soil(g) 38.90 34.50 50.00 58.90 63.60

Weight of water(g) 2.90 3.80 7.20 9.90 12.10

Water content (%) 7.46 11.01 14.40 16.81 19.03


6/8


6

Table 2: Dry density determination for 5% cement

6.00 6.00 10.00 14.00 18.00 22.00

Water Content

(%)

7.46 11.01 14.40 16.81 19.03

Weight ofMould(g) 3114.00 3114.00 3114.00 3114.00 3114.00

Weight ofsoil+mould

4874.00 4953.00 5069.00 5020.00 4997.00

Weight of soil in

mould(g)

1760.00 1839.00 1955.00 1906.00 1883.00

Wet

density,(g/cm3)

1.76 1.84 1.96 1.91 1.88

Dry density(g/cm3)

1.64 1.66 1.71 1.63 1.58

RESULTS

Optimum moisture content =13%

Maximum dry density = 1.88g/cm3


7/8


7

Optimum Moisture content = 14% Maximum dry density = 1.72g/cm3

DISCUSSION

In this investigation, results were obtained for samples with 5% and 7.5% cement content by mass.

For the sample with 5% cement, the maximum dry density found (1.88g/cm3) was higher than that

found for 7.5%. (1.72g/cm3). However, there was a higher Optimum moisture content by the

sample with 7.5% cement (14%) than that with 5% cement. (13%). When compared with the

parameters obtained without a stabilizer, the maximum dry density obtained without stabilizer

(1.92g/cm3), was higher than both values obtained with the stabilizer.

To improve the results obtained with stabilization using cement, it would have been necessary to

first reduce the plasticity of the soil using lime. According to SATCC standards, as a guide,

materials suitable for cement treatment will normally have a low Plasticity Index of less than 10.

When a material has a higher plasticity, it must first be treated with lime before stabilizing with

cement. Stabilizing with cement directly is usually unsatisfactory. The use of high cement content

in pavement construction such as 5% or more is discouraged in SATCC standards, both for

economic and for performance considerations. Higher cement content can lead to greater cracking

potential which may influence the overall performance of the pavement. Trial mixes in thelaboratory should be made for a range of cement contents typically 2%, 4% and 6% by weight as

mix moisture contents appropriate to field mixing.

Addition of lime has been found very effective on many materials with high plasticity, normally

greater than 10, which will not respond so well to cement treatment. It may be used in order to

lower the Plasticity of materials otherwise within specified limits, as a pre-treatment of materials

that might then be treated with cement to produce suitable building material.


8/8


8

There were other factors which could have led to a lower maximum dry density in the stabilized

soil sample. Other causes of differences could have been due to delays between the times when

cement was added and compaction started. In cement stabilized soils, hydration process takes

immediately after the cement comes into contact with water. This process involves hardening of

the soil mix which means that it is necessary to compact the soil mix as soon as possible. Any

delays in compaction may result in hardening of stabilized soil mass and therefore extracompaction effort may be required to bring the same effect as that for a sample without stabilizer.

The other reason why the first value was higher is because in compacting with the stabilizer, the

same sample was used over and over while the cement in the sample was slowly curing. This may

lead to serious bond breakage and hence loss of strength. Another reason for such results could be

attributed to the fact that the two compaction tests were done under different time intervals and

there were slight variations in the samples used. The Optimum moisture content obtained without

the stabilizer was lower (12%) than that obtained with a stabilizer. This is because in stabilized

soils, enough moisture content is essential not only for hydration process to proceed but also for

efficient compaction.

CONCLUSION

With reference to the objectives of the experiment, it was found that the Optimum Moisture

Content for the soil sample was 13% and the maximum dry density was 1.88g/cm3 for 5% cement

content. For the 7.5% cement sample Optimum Moisture Content was 14% and the maximum dry

density was 1.72g/cm3. Stabilization with cement decreased the MDD while there was an increase

in the OMC as cement was increasingly added. Finally, stabilized mixture had a lower maximum

dry density than that of unstabilized soil for a given degree of compaction and a higher Optimum

moisture content.

RECOMMENDATIONS

It is recommended that in the future, the practical involving the stabilizer and that without the

stabilizer be carried out on the same day to allow for a higher degree of consistency when

comparing the results and to ensure that the samples used are very similar. Also that the CBR test

be carried on the stabilized soil sample as well since in this case, it was not done.

REFERENCES

1. Ministry of Works(CML), Tanzania (2000), Laboratory Testing Manual 2000,

novumGrafisk AS,Skjetten

2. SATCC (1998) Standard Specifications for Road and Bridge Works, Division of Roads

and Transport Technology CSIR3. Venkatramaiah C., Geotechnical Engineering 3rd edition, New Age Internationa l

Publisher, India.

daniel siyingwa 12032174 compaction with stabilizer

Documents