Penetration Test
(As per IS: 1203)
Apparatus:
1. Standard Penetration apparatus
2. A metal or glass cylindrical flat-bottomed container essentially with the following dimensions:
For penetration below 225
Diameter 55mm
Internal depth 35mm
For penetration between 225 and 350
Diameter 70mm
Internal depth 45mm
3. Needle shall be made up of straight, highly polished, cylindrical, hard steel rod.
4. Water bath 10 liters capacity thermostatically controlled and maintained within the temperature of 25±0.1 0C.
5. Thermometer capable of reading temperature up to 250 0C.
Procedure:
● Soften the material to a pouring consistency at a temperature not more than 60 0C for tars and pitches and not more
than 90 0C for bitumen above the approximate respective softening points.
● Stir it thoroughly until it is homogeneous and free from air bubbles and water.
● Pour the melt in to the container to a depth of at least 10mm in excess of the expected penetration.
● Protect the sample from dust and allow it to cool in atmosphere at a temperature between 15 to 30 0C for 11/2 to
2hours for 45mm deep container and 1 to 11/2 hours for 35mm deep container.
● Unless otherwise specified carry out testing at a temperature of 25 + 0.1oC.
6. Place it along with the transfer dish in the water bath at 25 + 0.10C and allow it remain for 11/2 to 2hours for 45mm
deep container and 1 to 11/2 hours for 35mm deep container.
7. Fill the transfer dish with water from the water bath to a depth sufficient to cover the mould completely.
8. Remove the transfer dish along with the mould from water bath after specified period of time and put it upon the
stand of penetration apparatus.
9. Adjust the needle (previously washed, cleaned well with benzene and dried) just to make contact with the surface of
the sample.
● The sum of the weights of the needle, carrier and super imposed weights i.e. the total moving weight shall be 100
0.25grams.
● Bring the pointer to zero.
● Release the needle for five seconds and measure the distance penetrated.
● Make at least three determinations at points on the surface of the sample not less than 10mm apart and not less than
10mm from the side of the dish.
● After each test, return the sample and transfer dish to the water bath and wash the needle with benzene and dry.
● In case of material of penetration greater than 225 make three determinations on each of two identical test
specimens using a separate needle for each determination, leaving the needle in the sample on completion of each
determination to avoid disturbance of the specimen.
