STANDARD
IS: 6241-1971.
DEFINITION
The stripping value of aggregates is determined as the ratio of the uncovered area observed visually to the total area of aggregates, expressed as a percentage.
APPARATUS
Heat resistant glass beaker of 500 ml capacity.
20mm and 12.5mm IS sieves.
Mixer.
Balance of capacity 10Kg and sensitivity 1gram.
Water bath preferably with a thermostat.
PROCEDURE
Take 200 grams of dry and clean aggregates passing 20mm and retained on 12.5mm sieves and heat up to 1500 C.
Take five percent by weight of bitumen binder and heat up to 1600 C.
Mix the aggregates and the binder till they are completely coated and transfer the mixture in to a 500ml beaker and allow to cool at room temperature for about 2 hours.
Add distilled water to immerse the coated aggregates.
Cover the beaker and keep in a water bath maintained at 400 C taking care that the level of water in the water bath is at least half the height of the beaker. Bitumen coated aggregates Aggregates kept out side for kept in distilled water observation of stripping of bitumen coating .
After 24hours take the beaker out, cool at room temperature and estimate the extent of stripping visually while the specimen is still under the water.
REPORT
Express the stripping value as the ratio of the uncovered area observed visually to the total area of aggregates in each test.
Report the mean of three results as stripping value of the tested aggregates to the nearest whole number.
PRECAUTION
Care shall be taken while mixing aggregates with bitumen.
IS: 6241-1971.
DEFINITION
The stripping value of aggregates is determined as the ratio of the uncovered area observed visually to the total area of aggregates, expressed as a percentage.
APPARATUS
Heat resistant glass beaker of 500 ml capacity.
20mm and 12.5mm IS sieves.
Mixer.
Balance of capacity 10Kg and sensitivity 1gram.
Water bath preferably with a thermostat.
PROCEDURE
Take 200 grams of dry and clean aggregates passing 20mm and retained on 12.5mm sieves and heat up to 1500 C.
Take five percent by weight of bitumen binder and heat up to 1600 C.
Mix the aggregates and the binder till they are completely coated and transfer the mixture in to a 500ml beaker and allow to cool at room temperature for about 2 hours.
Add distilled water to immerse the coated aggregates.
Cover the beaker and keep in a water bath maintained at 400 C taking care that the level of water in the water bath is at least half the height of the beaker. Bitumen coated aggregates Aggregates kept out side for kept in distilled water observation of stripping of bitumen coating .
After 24hours take the beaker out, cool at room temperature and estimate the extent of stripping visually while the specimen is still under the water.
REPORT
Express the stripping value as the ratio of the uncovered area observed visually to the total area of aggregates in each test.
Report the mean of three results as stripping value of the tested aggregates to the nearest whole number.
PRECAUTION
Care shall be taken while mixing aggregates with bitumen.
