Penetration Test for Bitumen

PENETRATION
TEST
Shweta Sagar & Juhita
M.Tech. CTM
1st sem
PENETRATION TEST OF BITUMEN

AIM
(i) To determine the consistency of the bituminous
material.
(ii)To assess the suitability of bitumen for use under
different climatic conditions and various types of
construction.

APPARATUS
(i) Container: A flat bottomed cylindrical metallic
dish 55mm in diameter and 35 mm in depth is
required. If the penetration is of the order of 225
or more, dish of 70mm diameter and 45mm depth
is required.
(ii)Transfer dish or tray: Should provide support to
the container & should not rock it. It should be of
such capacity as to completely immerse container
during test.

(iii) Water bath: Water bath maintained at 25 ± 0.1 °C,
containing not less than 10 litres of water, the
sample being immersed to a depth not less than
100 mm from top and supported on perforated
shelf not less than 50 mm from bottom of the bath.
(iv) Needle: A straight, highly polished, cylindrical
hard steel rod.
(v) Thermometer: Range 0°C - 44°C and in readable
up to 0.20°C.

(vi) Penetration apparatus: Should be such that it
allows needle to penetrate without much
friction & is accurately calibrated to give
results in one tenth of a millimeter.
(vii) Time measuring device: With an accuracy of
a second.

THEORY
Penetration value is a measure of hardness or
consistency of bituminous material. It is the vertical
distance traversed or penetrated by the point of a
standard needle in to the bituminous material under
specific conditions of load, time and temperature. This
distance is measured in one tenths of a millimeter.
This test is used for evaluating consistency of
bitumen. It is not regarded as suitable for use in
connection with the testing of road tar because of the
high surface tension exhibited by these materials.

PROCEDURE
(i) Preparation of test sample: Soften the material to a
pouring consistency at a temperature not more than
60°C for tars and 90°C for bitumen above the
approximate softening point and stir it thoroughly until
it is homogeneous and is free from air bubbles and
water. Pour the melt into the container to a depth at
least 10mm in excess of the expected penetration.
Protect the sample from dust and allow it to cool in an
atmosphere at a temperature between 15°C to 30°C for
one hour. Then place it along with the transfer dish in
the water bath at 25°C ± 0.1°C, unless otherwise
stated.

(ii) Fill the transfer dish with water from the water bath to
depth sufficient to cover the container completely,
place the sample in it and put it upon the stand of the
penetration apparatus.
(iii) Clean the needle with benzene, dry it and load with
the weight. The total moving load required is 100 ±
0.25 grams, including the weight of the needle, carrier
and super-imposed weights.
(iv) Adjust the needle to make contact with the surface of
the sample. This may be done by placing the
needlepoint in contact with its image reflected by the
surface of the bituminous material.

(v) Make the pointer of the dial to read zero or note the
initial dial reading.
(vi) Release the needle for exactly five seconds.
(vii) Adjust the penetration machine to measure the
distance penetrated.

(viii) Make at least 3 readings at points on the
surface of the sample not less than 10 mm apart
and not less than l0mm from the side of the dish.
After each test return the sample and transfer
dish to the water bath and wash the needle clean
with benzene and dry it. In case of material of
penetration greater than 225, three
determinations on each of the two identical test
specimens using a separate needle for each
determination should be made, leaving the
needle in the sample on completion of each
determination to avoid disturbance of the
specimen.

RECORD OF OBSERVATION
PENETROMETER DIAL READING TEST 1 TEST 2 TEST 3
(A) Initial 200 264 333
(B) Final 264 333 407
PENETRATION VALUE 64 69 74
Actual Test Temperature(°C) = 25°C
Mean Penetration Value = 69

RECOMMENDED VALUE AS
PER IS CODE 73:2006
BITUMEN GRADE PENETRATION VALUE
A-35 30-40
A-45 40-50
A-55 50-60
A-65 60-70
A-90 80-100
A-200 175-225

Download@notescvil.blogspot.in

PRECAUTION
(i) There should be no movement of the container
while needle penetrates into sample.
(ii) The sample should be free from any extraneous
matter.
(iii) The needle should be cleaned with benzene and
dried before penetration.

Thank You

Penetration Test for Bitumen

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Penetration Test for Bitumen