SOFTENING POINT of Bitumen

Updated: Jul 16, 2020

AIM

To determine the softening point of asphaltic bitumen and fluxed

native asphalt, road tar, coal tar pitch and blown type bitumen as

per IS: 1205 - 1978.

PRINCIPLE

It is the temperature at which the substance attains a particular

degree of softening under specified condition of the test.

APPARATUS



RING AND BALL APPARATUS

i) Ring and ball apparatus

ii) Thermometer - Low Range : -2 to 80 °C, Graduation 0.2 °C

- High Range : 30 to 200 °C, Graduation 0.5 °C

PREPARATION OF SAMPLE

i) The sample should be just sufficient to fill the ring. The

excess sample should be cut off by a knife.

ii) Heat the material between 75 and 100 °C. Stir it to remove

air bubbles and water, and filter it through IS Sieve 30, if

necessary.

iii) Heat the rings and apply glycerine. Fill the material in it and

cool it for 30 minutes.

iv) Remove excess material with the help of a warmed, sharp

knife.

PROCEDURE

A) Materials of softening point below 80 °C:

i) Assemble the apparatus with the rings, thermometer and

ball guides in position.

ii) Fill the beaker with boiled distilled water at a temperature

5.0 ± 0.5 °C per minute.

iii) With the help of a stirrer, stir the liquid and apply heat to

the beaker at a temperature of 5.0 ± 0.5 °C per minute.

iv) Apply heat until the material softens and allow the ball to

pass through the ring.

v) Record the temperature at which the ball touches the

bottom, which is nothing but the softening point of that

material.

B) Materials of softening point above 80 °C:

The procedure is the same as described above. The only

difference is that instead of water, glycerine is used and the

starting temperature of the test is 35 °C.

REPORTING OF RESULTS

Record the temperature at which the ball touches the bottom.

3 views0 comments

Recent Posts

See All