- The stripping value of aggregates is determined as the ratio of the in covered area observed visually to the total area of aggregates, expressed as a percentage.
- Heat resistant glass beaker of 500 ml capacity.
- 20mm and 12.5 mm IS sieves.
- Balance of capacity 10Kg and sensitivity 1 gram.
- Water bath preferably with a thermostat.
- Take 200 grams of dry and clean aggregates passing 20mm and retained on 12.5mm sieves and heat up to 150°C.
- Take five percent by weight of bitumen binder and heat up to 160°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 40°C taking care that the level of water in the water bath is at least half the height of the beaker.
- After 24 hours take the beaker out, cool at room temperature and estimate the extent of stripping visually while the specimen is still under the water.
- Express the stripping value as the ratio of the covered 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.
- Care shall be taken while mixing aggregates with bitumen.
DETERMINATION OF STRIPPING VALUE OF AGGREGATES
|Description||Units||Test I||Test 2||Average|
|Wt. of dry aggregates||gms|
|Temperature of aggregates||°C|
|Wt. of bitumen||gms.|
|Retained coating observed||%|
|Specified Limit: Minimum retained coating observed should be 95% (Minimum)|