Procedure

1. Collect about a minimum number of 200 pieces of aggregate of any fraction.
2. Sieve the sample through the IS specified sieves, stacked in proper sequence.
3. For the separation of elongated material, each fraction of aggregate shall be gauged on the length gauge.
4. Weigh the total amount of elongated material that has passed the length gauge to an accuracy of 0.1 % of the weight of the sample.
5. Elongation index is calculated by expressing the total weight of the material that is passing the length gauge as a percentage of the total weight of the sample gauged.