FACULTY OF CIVIL ANG ENVIRONMENTAL ENGINEERING

DEPARTMENT OF INFRASTRUCTURE AND GEOMETIC

LAB GEOTECHNIC

FULL REPORT

Subject Code BFC 31703

Code & Experiment Title OPEN ENDED - DETERMINATION OF SPECIFIC GRAVITY

BY PYCNOMETER TEST

Course Code 2 BFF

Date 10TH

MAY 2012

Section / Group SECTION 9 / GROUP 7

Name MUHAMMAD IKHWAN BIN ZAINUDDIN (DF100018)

Members of Group 1. NUR EZRYNNA BINTI MOHD ZAINAL (DF100118)

2. MUHAMMAD HUZAIR BIN ZULKIFLI (DF100040)

3. NUR EEZRA ATHIRLIA BINTI GHAZALI (DF100147)

4. MUHAMMAD NUH BIN AHMAD ZAIRI (DF100093)

5. ZIRWATUL FAUZANA BINTI CHE JEMANI (DF100027)

Lecturer/Instructor/Tutor EN. AHMAD HAKIMI BIN MAT NOR

Received Date 17TH

MAY 2012

Comment by examiner

Received

STUDENT CODE OF ETHIC

(SCE)

DEPARTMENT OF INFRASTRUCTURE AND GEOMETIC FACULTY OF CIVIL & ENVIRONMENTAL ENGINEERING

UTHM

We, hereby confess that we have prepared this report on our effort. We also admit not to receive

or give any help during the preparation of this report and pledge that everything mentioned in

the report is true.

___________________________

Student Signature

Name : MUHAMMAD IKHWAN BIN ZAINUDDIN

Matric No. : DF100018

Date : 17/05/2012

_______________________

Student Signature

Name : MUHAMMAD NUH BIN AHMAD ZAIRI

Matric No. : DF100093

Date : 17/05/2012

___________________________

Student Signature

Name : NUR EEZRA ATHIRLIA BINTI GHAZALI

Matric No. : DF100147

Date : 17/05/2012

___________________________

Student Signature

Name : MUHAMMAD HUZAIR BIN ZULKIFLI

Matric No. : DF100040

Date : 17/05/2011

___________________________

Student Signature

Name : NUR EZRYNNA BINTI MOHD ZAINAL

Matric No. : DF100118

Date : 17/05/2012

_______________________

Student Signature

Name : ZIRWATUL FAUZANA BINTI CHE JEMANI

Matric No. : DF100027

Date : 17/05/2012

OPEN ENDED LAB DETERMINATION OF SPECIFIC GRAVITY BY

PYCNOMETER TEST

1.0 OBJECTIVE

The specific gravity (Gs) of a soil is defined as the ratio between the unit massesof soil

particles and water. Gs is useful for determining weight-volume relationships.

2.0 INTRODUCTION

The pycnometer (from the Greek puknos, meaning "density", also called pyknometer or

specific gravity bottle), is a flask with a close-fitting ground glass stopper with a fine hole

through it, so that a given volume can be accurately obtained. This enables the density of a fluid

to be measured accurately, by reference to an appropriate working fluid such as water or mercury,

using an analytical balance.

If the flask is weighed empty, full of water, and full of a liquid whose specific gravity is

desired, the specific gravity of the liquid can easily be calculated. The particle density of a

powder, to which the usual method of weighing cannot be applied, can also be determined with a

pycnometer. The powder is added to the pycnometer, which is then weighed, giving the weight of

the powder sample. The pycnometer is then filled with a liquid of known density, in which the

powder is completely insoluble. The weight of the displaced liquid can then be determined, and

thence the specific gravity of the powder.

Base on American Standard Test Method (ASTM D854), these test methods cover the

determination of the specific gravity of soil solids that pass the 4.75-mm (No. 4) sieve, by means

of a water pycnometer. When the soil contains particles larger than the 4.75-mm sieve, Test

Method C127 shall be used for the soil solids retained on the 4.75-mm sieve and these test

methods shall be used for the soil solids passing the 4.75-mm sieve.

The specific gravity of solid Gs is a dimensionless parameter that relates the density of

the soil particles ρsto the density of water ρw, or Gs = ρs/ρw. The density of the soil particles ρs is

defined as the mass in air of dry solids Ms at a stated temperature divided by the volume of the

solid Vs at the same stated temperature, or ρs= Ms/Vs.

3.0 NEED AND SCOPE OF EXPERIMENT

The knowledge of a specific gravity is needed in calculation of soil properties like void

ratio, dgree of saturation etc.

4.0 THEORY

The specific gravity (Gs) of a material is defined as the ratio of the weight (or mass) of a

given volume of the material to the weight (or mass) of an equal volume of water. In the case of a

density bottle method:

A sample of pre-dried soil is placed in a standard density bottle, of which the mass

including the stopper is m1. The combined mass of soil, bottle and stopper is m2. De-aired,

distilled water is a added and the whole vacuumed to remove air prior to topping up and

insertion of the stopper. After drying the outside of the bottle, stopper, soil and water, m3 is

determined. The bottle is then emptied, refilled with de-aired water only, the exterior again dried

and the mass of bottle, stopper and water, m4 is recorded.

Then,

Gs = mass of soil particles

mass of an equal volume of water

and is found from the expression :

Gs = m2 – m1

(m4 – m1) - (m3 – m2)

Where :

m2 – m1 is the mass of soil sample;

m4 – m1 is the mass of water contained by the density bottle;

m3 – m2 is the mass of water occupying a volume equal to that of the soil particles.

Hence the specific gravity Gs of a soil is calculated as follows;

Gs = Ws

Ws + WFW – WFS

Where Ws is the weight of the dry soil, WFS is the weight of the flask filled with soil and

water and WFW is the weight of the flask filled with deaired water only.

5.0 APPARATUS

Figure 1 – Volumetric Flacks

(250 or 500 ml)

with stoppers,

numbered and

calibrated

Figure 2 – Distilled deaired

water

Figure 3 – Weighing Scale

accurate to 0.01g

Figure 4 – Vacuum Pump Figure 5 – Two types of soils,

clay and sand.

Figure 7 – Drying Oven Figure 6 – Thermometer, ranging

from 0 to 500,

accurate 0.50 C.

6.0 PROCEDURE

i. Soil samples taken from the sample is dried in an oven with a temperature of 105-110oC,

then cooled in a dryer.

ii. Density bottle and stopper were properly cleaned and dried.

iii. The weight of dried bottle with stopper were weighted and recorded (m1).

iv. The oven-dried soil sample cooled in dessicator about 10 grams was took and poured

carefully into the density water. The mass was recorded (m2).

v. The bottle was half-full with poured some distilled water into it. The bottle without the

stopper was keep into the vacuum desiccator for about 1 hour until there is no further loss

of air.

vi. The bottle was full with distilled water without any entrapped bubble. The stopped was

put.

vii. The full bottle with water, soil samples and stopper were weighted. The mass was

recorded (m3).

viii. The bottle was empty and cleaned properly. The entire bottle was full with distilled water

without any trapped air bubbles.

ix. The stopper was put on as in step (iv) and dried from outside. The mass was recorded

(m4). Then the bottle was empty and dried.

7.0 DATA SHEET

Table 1 :

Location:Geotechnic laboratory Loc. No:

Soil description : Sample No.

Sample Type : Clay & Silt Depth of Sample :

Operator : Group 7 Date Started : 10 / 5 /2012

Test no. 1 2 3 4

Type of soil Clay Silt

Bottle no 2 4 3 13

Mass of density bottle and stopper, g

(m1) 30.26 29.83 28.10 28.36

Mass of density bottle plus stopper plus

oven dry soil, g (m2) 40.26 39.83 38.10 38.36

Mass of density bottle plus stopper plus

soil plus distilled water, g (m3) 79.53 79.43 78.22 78.24

Mass of density bottle plus stopper plus

distilled water ,g (m4) 73.05 73.05 72.03 72.03

Mass of soil sample, g (m2 - m1) 10.00 10.00 10.00 10.00

Mass of water contained by the density

bottle, g (m4 – m1) 42.79 43.22 43.93 43.67

Mass of water occupying the volume not

occupied by the soil and thus, g (m3 – m2) 39.27 39.60 40.12 39.88

Mass of water occupying a volume equal

to that of the soil particles, g (m4 – m1) -

(m3 – m2)

3.52 3.62 3.81 3.79

Gs = Mass of soil particles

Mass of an equal volume of water

Gs = (m2 - m1)

(m4 – m1) - (m3 – m2)

2.8 2.76 2.6 2.6

AVERAGE SPECIFIC GRAVITY, Gs 2.78

8.0 CALCULATION

a) Mass of density bottle and stopper, g (m1) = 30.26

b) Mass of density bottle plus stopper plus oven dried soil, g (m2) = 40.26

c) Mass of density bottle plus stopper plus soil plus distilled water, g (m3)=79.53

d) Mass of density bottle plus stopper plus distilled water, g (m4) = 73.05

1. Mass of soil sample, g (m2-m1) = 40.26 - 30.26

= 10

2. Mass of water contained by the density bottle, g (m4-m1) = 73.05 – 30.26

= 42.79

3. Mass of water occupying the volume not occupied by the soil and thus, g (m3-m2)

= 79.53 – 40.26

= 39.27

4. Mass of water occupying a volume equal to that of the soil particles, g

(m4-m1) - (m3-m2) = 42.79 – 39.27

= 3.52

5. Gs = Mass of soil particles (m2 – m1)

Mass of an equal volume of water (m4-m1) - (m3-m2)

= 10/3.52

= 2.8

Average Specific Gravity = ∑Gs / ∑sample

= (2.8+2.76) / 2

= 2.78

Data during experiment:

Calculation after experiment:

Clay bottle no 2

a) Mass of density bottle and stopper, g (m1) = 28.10

b) Mass of density bottle plus stopper plus oven dried soil, g (m2) = 38.10

c) Mass of density bottle plus stopper plus soil plus distilled water, g (m3)=78.22

d) Mass of density bottle plus stopper plus distilled water, g (m4) = 72.03

1. Mass of soil sample, g (m2-m1) = 38.10 - 28.10

= 10

2. Mass of water contained by the density bottle, g (m4-m1) = 72.03 – 28.10

= 43.93

3. Mass of water occupying the volume not occupied by the soil and thus, g (m3-m2)

= 78.22– 38.10

= 40.12

4. Mass of water occupying a volume equal to that of the soil particles, g

(m4-m1) - (m3-m2) = 43.93– 40.12

= 3.81

5. Gs = Mass of soil particles (m2 – m1)

Mass of an equal volume of water (m4-m1) - (m3-m2)

= 10/3.81

= 2.6

Average Specific Gravity = ∑Gs / ∑sample

= (2.6+2.6) / 2

= 2.6

Data during experiment:

Calculation after experiment:

Silt bottle no 3

9.0 DISCUSSION

Specific Gravity (Gs) is the second most important parameter in soil mechanics. It is the

ratio of the unit weight (or density) of soil solids to the unit weight (or density) of water. Vacuum

was use in this while determining the specific gravity of soils to remove the entrapped air. Water

temperature may have a significant effect on performance of the gas pycnometer. Therefore,

testing should be conducted within the specified operating temperature range of the apparatus.

The specific gravity is required in calculation of various soil properties such as:

i. Void ratio

ii. Degree of saturation

iii. Weight-volume relationships

The specific gravity of most common minerals found in soils fall within a

range of 2.6 to 2.9. The specific gravity of sandy soil, which is mostly made of quartz, may be

estimated to be about 2.65, whereas for clayey and silty soils, it may vary from 2.6 to 2.9. Soils

containing organic matter and porous particles may have specific gravity values below 2.0, while

soils having heavy substances may have values above 3.0. All four groups ended up with specific

gravity values very close to 2.65. These values fall into the average specific value range for most

soils.

10.0 CONCLUSION

The specific gravity of a substance, designated as Gs, is defined as the ratio of the density

of that substance to the density of distilled water at a specified temperature. Since it is a ratio, the

value of Gs does not depend on the system of units used and is a numerical value having no units.

In soil mechanics, the specific gravity of soil solids is an important parameter and is a

factor in many equations involving weight-volume relationships. Specific gravity of soil solids

refers only to the solid phase of the three phase soil system, it does not include the water and air

phases present in the void space. For soil solids, Gs may be written as:

Gs = density of the soil solids = mass of soil solids

density of water mass of an equal volume of water

11.0 APPENDIXES

PROCEDURES OF BOILING METHOD

i) Measure the specific gravity of your cleared wine sample and record the measurement

along side the temperature the measurement was taken at.

ii) Correct for the temperature difference between the recorded temperature and the

temperature the hydrometer was calibrated at, using the chart values for hydrometers

calibrated at 20oC, and record the true specific gravity of the wine sample as SG1.

iii) Measure out exactly 250ml of the wine sample in a 250 ml volumetric flask - (see

method).

iv) Empty the wine out of the volumetric flask into the distillation flask and employ a couple

of distilled water rinses to remove wine residues from the volumetric flask into the

distillation flask.

v) Add some boiling chips to the distillation flask to prevent bumping when boiling the

contents.Caution: do not add the boiling chips once heating has commenced.

vi) Set up apparatus as per diagram using only the boiling flask. A vertical splash head may

be fitted if desired.

vii) Apply heat to the bottom of the boiling flask and boil the wine down to approximately

125ml.If the heat from the burner is to local or intense, position a tripod and heat diffuser

(gauze), to disperse the applied heat, between the heat source and boiling flask.

viii) Allow the wine to cool down and using a funnel, carefully pour the remaining wine into

the same 250ml volumetric flask used to measure the wine volume at the start.

ix) Rinse out the remaining wine residues with a few rinses of distilled water, into the same

volumetric flask.

x) Top up the contents of the volumetric flask with distilled water close to 250 ml, bring to

20oC in a hot water bath, then top up to the 250ml graduation mark. Stopper and mix (see

method).

xi) Use a small amount the collected, diluted distillate to rinse a clean 250ml measuring

cylinder. Then fill a 250ml measuring cylinder with the distillate.

xii) Using an specific gravity hydrometer, measure the specific gravity of the alcohol depleted

wine solution and record your reading.

xiii) Using a thermometer measure the temperature of the solution and record your reading.

xiv) Correct for the temperature difference between the recorded temperature and the

temperature the hydrometer was calibrated at, using the chart values for hydrometers

calibrated at 20oC, and record the true specific gravity of the alcohol depleted wine

solution as SG2.

xv) Using the equation below to calculate the alcohol concentration of you wine sample and

record the result.

Alcohol (% v/v EtOH) = (SG2-SG1) / 2.11 * 1000

11.0 REFERENCES

BrajaM.Das, Principles of Geotechnical Engineering. Seventh Edition. SI Edition.

Cengage Learning.

ASTM D854 , Standard Test Methods for Specific Gravity of Soil Solids by Water

Pycnometer1

http://mizisystem.blogspot.com/2012/01/lab-report-specific-gravity.html

K.H.Head, MA (Cantab), C.Eng, FICE, FGS, Manual of Soil Laboratory Testing

(volume 1), Second Edition, Pentech Press.

http://infohost.nmt.edu/~Mehrdad/ME420/assets/pdf/SpecificGravity.pdf

http://www.uic.edu/classes/cemm/cemmlab/Experiment%204-

Specific%20Gravity.pdf

http://www.uta.edu/ce/geotech/lab/Main/SmpLbRprt.pdf