SPECIFIC GRAVITY TEST.


SPECIFIC GRAVITY TEST.
( IS : 1202 – 1978 )

Object:

To determine the specific gravity of the bitumen by specific gravity bottle.

Apparatus:

a) Pycnometer / specific gravity bottle – 50 ml capacity.

b) Balance – sensitivity 0.1mg.

Procedure:

The specific gravity bottle is cleaned, dried and weighed along with the stopper. It is filled with fresh distilled water, stopper placed and the same is kept in water container for at least half an hour at temperature 270C +/- 10C. The bottle is then removed and cleaned from outside. The specific gravity bottle containing distilled water is now weighed.

The bituminous material is heated to a pouring temperature and is poured in the above empty bottle taking all the precautions that it is clean and dry before filling sample materials. The material is filled up to the half taking care to prevent entry of air bubbles. To permit an escape of air bubbles, the sample bottle is allowed to stand for half an hour at suitable temperature cooled to 270C and then weighed. The remaining space in the specific gravity bottle is filled with distilled water at 270C, stopper placed and is placed in water container at 270C. The bottle containing bituminous material and remaining water is removed, cleaned from outside and is again weighed.

Calculations:
The specific gravity of the bituminous material is calculated as follows:

                           Weight of bituminous material                          ( c – a )
Specific gravity =                                                                       =
                               Weight of equal volume of water at 270C         (b – a) – (d – c)   

Where        a        =  weight of the specific gravity bottle 
                   b       =  weight of the sp.gravity bottle filled with distilled water.
                   c        =  weight of the sp.gravity bottle about half filled with bitumen.
                   d       =  weight of the sp.gravity bottle about half filled with bitumen and      
                                         the distilled water.

Limits: Specific gravity of Bitumen at 270C is Minimum 0.99.
























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