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
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
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
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
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:
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:
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
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
