This document describes a penetration test performed on bituminous materials to determine consistency. The test involves vertically penetrating samples of the material with a standard needle under controlled conditions and measuring the penetration distance. Bitumen is characterized based on penetration grades like 30/40 and 40/50, with higher values indicating softer consistency. The document outlines the test apparatus, sample preparation process, testing procedure, and results, noting a mean penetration value of 37.37mm for the tested sample.
2. Transportation Engineering Laboratory. Engr. Sayed Shajedul Hasan
PENETRATION
Consistency of a bituminous material expressed as the distance in tenths of a millimeter that a
standard needle vertically penetrates a sample of the material under known conditions of loading,
time, and temperature.
GRADES OF BITUMEN:
Bitumen is usually characterized in the following three types of grades;
Viscosity grades
Penetration grades
Density grades
ASTM D946-09 Penetration Grades:
Bitumen 30/40
Hardest of all the grade and can withstand very heavy traffic loads.
Used in airport runways and also in very heavy traffic volume load in coastal cities.
Bitumen 40/50
Due to its high air blowing and penetration, it is used in tropical areas with the Warm weather. It
is not softened at high temperature and does not fail its qualities.
Bitumen 60/70
Due to its medium air blowing and penetration, it is used in road in mild areas.
Bitumen 80/100
Softest of all grades and suitable for low volume roads.
Bitumen 80/100
Due to its relatively low air blowing and penetration, It is used in areas with cold weather for asphalting
and insulation. It is not cracked in low temperature.
Bitumen 120/150:
Bitumen 200/300:
3. Transportation Engineering Laboratory. Engr. Sayed Shajedul Hasan
SCOPE & SIGNIFICANCE
• The penetration test is used as a measure of consistency. Higher values of penetration
indicate softer consistency.
• The test is widely used all over the world for classifying bituminous materials into
different grades.
Precautions during Penetration Test
• There should be no movement of the container while needle penetrates into sample.
• The sample should be free from any extraneous matter.
• The needle should be cleaned with benzene and dried before penetration.
4. Transportation Engineering Laboratory. Engr. Sayed Shajedul Hasan
Apparatus
Standard penetrometers
Sample cups needles
Penetration Needle: Approximately 60mm length, dia 1.0
to1.02mm.
Sample cup: dia 55 mm and depth 35 mm.
Glass transfer dish
Simple water bath
Timing Device
Thermometers
5. Transportation Engineering Laboratory. Engr. Sayed Shajedul Hasan
Preparation of test specimen:
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° to 30° C for one hour. Then place it along with the transfer dish
in the water bath at 25° ± 0.1 °C, unless otherwise stated.
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.
Clean the needle with benzene, dry it and load with the weight. The total moving load
required is 100 ± 0.25 gms, including the weight of the needle, carrier and super-imposed
weights.
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.
Procedure
Make the pointer of the dial to read zero or note the initial dial reading.
Release the needle for exactly five seconds.
Adjust the penetration machine to measure the distance penetrated.
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.
6. Transportation Engineering Laboratory. Engr. Sayed Shajedul Hasan
REPORT
OBSERVATIONS & RESULTS
Actual test temperature = 27°C
PENETRATION DIAL READING Test 1 Test 2 Test 3
INITIAL 0 0 0
FINAL 37.40 37.55 37.16
PENETRATION VALUE 37.40 37.55 37.16
Mean Penetration Value =37.37mm.
COMMENTS
The experiment has been performed successfully and the mean penetration value came out to be
37.37mm.
According to the tables the values ranging from 0 to 49 should have difference of maximum 2.
In our case the difference is =37.55 – 37.16 = 0.39 which is lesser then 2 so our performed
experiment and the penetration value is correct.
We performed the experiment at room temperature.
Date of experiment: 01-July-2019 Engr. Sayed Shajedul Hasan.
7. Transportation Engineering Laboratory. Engr. Sayed Shajedul Hasan
OBSERVATIONS & RESULTS
Actual test temperature = °C
PENETRATION DIAL READING Test 1 Test 2 Test 3
INITIAL
FINAL
PENETRATION VALUE
Mean Penetration Value = mm.
Comments
The experiment has been performed successfully and the mean penetration value came out to be
mm.
According to the tables the values ranging from to should have difference of maximum .
In our case the difference is = – = which is lesser then so our performed experiment
and the penetration value is correct.
We performed the experiment at room temperature.
Date of experiment: Engr. Sayed Shajedul Hasan.