Correct Answer - Option 1 : 5%
Explanation:
Bitumen adheres well to all normal types of road aggregates provided they are dry and free from dust. In the absence of water, there is practically no adhesion problem of bituminous construction. Adhesion problem occurs when the aggregate is wet and cold. This problem can be dealt with by removing moisture from the aggregate by drying and increasing the mixing temperature. Further, the presence of water causes stripping of binder from the coated aggregates. These problems occur when the bitumen mixture is permeable to water.
IRC has specified the maximum value of stripping value of aggregate not to exceed 5%.