IS 1209 provides the specific gravity test for bitumen — part of the IS 1201-1220 bitumen test series. Specific gravity is used for volume-weight conversions in mix design and to detect adulteration.
Method for determining the specific gravity of bitumen, cutback bitumen, and other semi-solid bituminous materials using pycnometer.
Key Values
Test temperature27°C ± 0.1°C
VG-30 specific gravity0.97-1.02 typical
VG-10 specific gravity0.99-1.03 typical
Practical Notes
! Specific gravity is needed for calculating bitumen content by volume in Marshall mix design.
! Unusually low specific gravity may indicate adulteration with lighter petroleum fractions.
! Test must be done at exactly 27°C — even 1°C difference affects the fourth decimal place.