SPECIFIC GRAVITY TEST ON BITUMINOUS MATERIALS.

This test is done to determine the specific gravity of semi-solid bitumen road tars, creosote and anthracene oil.

1. Transportation Engineering Laboratory. Engr. Sayed Shajedul Hasan
Experiment no: 01


SPECIFIC GRAVITY TEST ON
BITUMINOUS MATERIALS.

2. Transportation Engineering Laboratory. Engr. Sayed Shajedul Hasan
SPECIFIC GRAVITY
The specific gravity of semi-solid bituminous material, asphalt cements, and soft tar pitches shall
be expressed as the ratio of the mass of a given volume of the material at 25 °C to that of an equal
volume of water at the same temperature.

OBJECTIVE
This test is done to determine the specific gravity of semi-solid bitumen road tars, creosote
and anthracene oil.

SCOPE & SIGNIFICANCE
 Specific gravity of a bitumen binder is a fundamental property frequently required as an
aid in classing binders for use in paving jobs.
 Bitumen weights sometimes have to be converted into volumes for asphalt concrete mix
design calculations for which a knowledge of specific gravity is essential.
 Specific gravity is also used in identifying the source of bitumen binder.
 Bitumen binder has specific gravity in the range of 0.97 to 1.02.
 In case bitumen contains mineral impurities the specific gravity will be higher. Thus it is
possible for a quantitative extraction of mineral impurity in bitumen.

3. Transportation Engineering Laboratory. Engr. Sayed Shajedul Hasan
Apparatus


BALANCE




THERMOMETER






WATER BATH







DISTILLED WATER

PYCNOMETER
glass, consisting of a cylindrical or conical vessel carefully ground to
receive an accurately fitting glass stopper 22 to 26 mm in diameter. The
stopper shall be provided with a hole 1.0 to 2.0 mm in diameter, the
stopper Pycnometer shall have a capacity of 24 to 30 ml, and shall
weigh not more than 40 grams.

4. Transportation Engineering Laboratory. Engr. Sayed Shajedul Hasan
Procedure




• The specific gravity bottle is cleaned, dried and weighed along with the stopper.
• It is filled with fresh distilled water, stopper placed and the same is kept in water
container for at least half an hour at temperature 27°C.
• The bottle is then removed and cleaned from outside. The specific gravity bottle
containing distilled water is now weighed.
• The bituminous material is heated to a pouring temperature and is poured in the above
empty bottle taking all the precautions that it is clean and dry before filling sample
materials. The material is filled up to the half taking care to prevent entry of air
bubbles.
• To permit an escape of air bubbles, the sample bottle is allowed to stand for half an
hour at suitable temperature cooled to 27°C and then weighed.
• The remaining space in the specific gravity bottle is filled with distilled water at 27°C,
stopper placed and is placed in water container at 27°C.
• The bottle containing bituminous material and containing water is removed, cleaned
from outside and is again weighed.

5. Transportation Engineering Laboratory. Engr. Sayed Shajedul Hasan
CALCULATIONS
Calculate the specific gravity to the nearest third decimal as follows:

Specific gravity =
(�−�)
[(�−�)−(�−�)]


Where,
A = mass of Pycnometer (+ stopper)
B = mass of Pycnometer filled with water
C = mass of Pycnometer partially filled with asphalt
D = mass of Pycnometer + asphalt + water


OBSERVATIONS & RESULTS

Group
Weight (gm)
Specific gravity

A
(gm)

B
(gm)

C
(gm)

D
(gm)

1
21.245

73.338

55.456

73.721

1.011


Comments

The experiment has been performed successfully and the specific gravity determined is 1.011gm
which is in the range of 0.97 to 1.02. So it is acceptable. There were no bubbles in the
pycnometer, so chance of error was eliminated and thus the value is correct.




Date of experiment: 30-JUNE-2019 Engr. Sayed Shajedul Hasan.

6. Transportation Engineering Laboratory. Engr. Sayed Shajedul Hasan



OBSERVATIONS & RESULTS





Group
Weight (gm)
Specific gravity

A
(gm)

B
(gm)

C
(gm)

D
(gm)

1
21.245

73.338

55.456

73.721

1.011




Comments

The experiment has been performed successfully and the specific gravity determined is which
is in the range of 0.97 to 1.02. So it is acceptable. There were no bubbles in the pycnometer, so
chance of error was eliminated and thus the value is correct.













Date of experiment: