Objective

To determinate the penetration of bitumen.

Reference Standard

IS : 1203-1978-Indian standard methods for testing tar and bituminious materials (Determination of penetration) 

Equipment & Apparatus

• Container
• Needle
• Stop watch
• Water bath
• Penetration apparatus
• Thermometer                              

Procedure 

1. The bitumen is softened to a paving consistency between 75⁰ C and 100⁰C above the approximate temp at which bitumen softens.
2. The sample material is thoroughly stirred to make it homogeneous and free from air bubbles and water.
3. The sample containers are cooled in atmosphere of temperature not lower than 13°C for one hour. Then they are placed in temperature controlled water bath at a temperature of 25°C for a Period of one hour.
4. The weight of needle, shaft and additional weight are checked. The total weight of this assembly should be 100 g.
5. Using the adjusting screw, the needle assembly is lowered and the tip of the needle is made to just touch the top surface of the sample.
6. The needle assembly is clamped in this position. The contact of the tip of the needle is checked using the mirror placed on the rear of the needle.
7. The initial reading of the penetrometer dial is either adjusted to zero or the initial reading is noted.
8. Then the needle is released by pressing a button and a stop watch is started. The needle is released exactly for a period of 5.0 secs.
9. At least 3 measurements are made on this sample by testing at distance of not less than 100 mm apart. 

Calculation

The difference between the initial and final penetration readings are taken as the penetration value.

Report

The average penetration value of 3 tests of a given bitumen sample is reported. 

 Safety & Precautions

• Use hand gloves, apron while removing containers from hot plate after switching off the hot plate.
•  No disturbance occurs at time of penetration.
• Use safety shoes & Apron at the time of test.
• Equipment should be cleaned thoroughly before testing & after testing.