TESTS ON BITUMEN
Penetration for Tar and bituminous Materials
This test is done as per IS: 1203 – 1978.Penetration of a bituminous material is the distance in tenths of millimeter that standard needle will penetrate vertically, into a sample under standard conditions of temperature, load and time.
Procedure:
- i) Heat the sample until it becomes fluid.
- ii) Pour it in a container to a depth such that when cooled, the depth of sample is at least 10mm greater than the expected penetration.
- iii) Allow it to cool in an atmospheric temperature.
- iv) Clean the needle and place a weight above the needle.
- v) Use the water bath to maintain the temperature of specimen.
- vi) Mount the needle on bitumen, such that it should just touch the surface of bitumen.
- vii) Then start the stop watch and allow the penetration needle to penetrate freely at same time for 5 seconds. After 5 seconds stop the penetration.
- viii) Result will be the grade of bitumen.Take at least three reading.
Uses:
- i) It measures the hardness or softness of bitumen by measuring the depth in tenths of a millimeter to which a standard loaded needle will penetrate vertically in 5 seconds
- ii) In hot climates, a lower penetration grade is preferred.