Page 44 - HIGHWAY ENGINEERING LABORATORY_FLIP BUILDER

Page :
WORK INSTRUCTION
Edition :
Checking No.
SOFTENING POINT OF
BITUMEN Effective Date:
CIVIL ENGINEERING
(Reference Standard:
JKA/ DCC30112/ 2021 AASHTO T 53-84) Amendment Date:

1.0 OBJECTIVE OF EXPERIMENT :

To determine the softening point of bitumen with range 30oC to 157oC by means of the
Ring and Ball apparatus..

2.0 SUMMARY OF THEORY :
Unlike some substances (e.g. water which changes from solid to liquid at 0 °C) bituminous

materials do not have a definite melting point. Instead, as the temperature rises, these
materials slowly change from brittle or very thick and slow-flowing materials to softer and less
viscous liquids. Being very simple in concept and equipment, the Ring-and-Ball Test has
remained a valuable consistency test for control in refining operations, particularly in the

production of air-blown bitumen. It is also an indirect measure of viscosity or, rather, the
temperature at which a given viscosity is evident. Softening Point (SP) together with
Penetration Value(P) are used to determine the Penetration Index (IP). IP can indicate the
properties of bitumen tested and its suitability. IP can be determined using nomograph or the

following equation (BS 4987):

IP = 1951.4 – 500 log P – 20 SP x 100
50 log P – SP – 120.14

Higway Engineering Laboratory page 31