Hardness Tester For Bitumen Mastic Asphalt

Hardness Tester For Bitumen Mastic Asphalt

Purpose:
Hardness tester for Mastic Asphalt has been fabricated to meet the essential requirements of IS 1195 - 1968 in finding out the Hardness Number of mastic asphalt.

Definition of Hardness Number:
Hardness Number is defined as the figure denoting the depth in hundreds of a centimeter, to which a flat ended indentation pin in the form of a steel rod 6.35 mm in diameter will penetrate the mastic under a load of 31.7 kg applied for 60 seconds, the temperature being maintained at 35' +/- 0.5' C or 45' +/- 0.5' C. The unit is complete with load release mechanism.

Construction Details:
The apparatus consist of a frame supported by means of four leveling screws. On the bottom of the top plate, a lever with a counter balance weight and a load hanger is fixed. The ratio of the lever is such that when the weight is kept on the hanger, the ultimate load acting on the penetration pin is 31.7 kg.
A thermometer is fixed by clip, which records the temperature of the water in the container.

The load transfer bar passes through the support bracket and rest on the specimen.
The penetration rod can be adjusted and locked before the test is conducted. An adjustable ring is Provided on the load transfer bar and rest point for the dial gauge of 0.01mm accuracy to record the depth of penetration.
The ring can be adjusted and locked in position for the initial setting of the dial gauge.
A cam which is operated by the handle is provided to lock or free the load transfer bar.
A load support rod and a bracket are provided to support the load while the adjustments are being made before the test is standard.