What is the standard pulling speed for the ductility test?

The clips must be pulled apart at a uniform speed of 50 ± 2.5 mm per minute.

At what temperature is the ductility test conducted in India?

The standard test temperature specified in IS 1208 is 27 ± 0.5 °C.

How is ductility measured and reported?

It is measured and reported as the distance in centimeters (cm) that the standard briquette stretches before the thread breaks.

What does the ductility value indicate about bitumen?

It indicates the material's ability to undergo deformation without rupture, highlighting its adhesive and tensile properties which are crucial for pavement durability.

IS 1208

: 1978

Methods for testing tar and bitumen: Determination of ductility

CurrentFrequently UsedTesting MethodTransportation · Waterproofing and Damp Proofing

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This standard outlines the test method for determining the ductility of bituminous materials by measuring the distance in centimeters to which a standard briquette elongates before breaking under specific conditions of temperature and speed.

Describes the method for determining the ductility of bituminous materials, indicating their ability to deform without breaking, relevant for waterproofing flexibility.

Quick Reference Values

standard test temperature27 ± 0.5 °C

rate of pull50 ± 2.5 mm/min

briquette cross section10 mm x 10 mm

water bath capacityAt least 10 litres

sample cooling time in air30 to 40 minutes

sample cooling time in water bath85 to 95 minutes

Practical Notes

Temperature control is highly critical; a deviation of even 0.5°C can significantly alter ductility results.

If the thread of bitumen sags and touches the bottom of the water bath, or floats to the surface, the specific gravity of the water must be adjusted (e.g., by adding methyl alcohol or sodium chloride) and the test repeated.

Carefully cut the excess bitumen from the briquette using a hot, straight-edged putty knife from the center towards the ends to prevent pulling the material out of the mould.