Determination of flakiness & elongation index (FI & EI) of coarse aggregate using thickness & length gauge. Shape and size aggregate is one of the major contributing factors to the quality of concrete. The test methods are given below for flakiness & elongation index of coarse aggregate.
Test standard : IS 2386-Part I: 1963
Test Appratus flakiness & elongation index
- Weighing Balance
- IS sieves 63mm, 50mm, 40mm, 31.5mm, 25mm, 20mm, 16mm, 12.5mm, 10nm, 6.3mm
- Thickness gauge for flakiness and length gauge for elongation.
Dimension of Thickness and Length gauge
Test procedure for FI & EI
Prepared the sample of Each fraction as:
- Passing 63mm IS Sieve & Retained on 50mm IS Sieve
- Passing 50mm IS Sieve & Retained on 40mm IS Sieve
- Passing 40mm IS Sieve & Retained on 31.5mm IS Sieve
- Passing 31.5mm IS Sieve & Retained on 25mm IS Sieve
- Passing 25mm IS Sieve & Retained on 20mm IS Sieve
- Passing 20mm IS Sieve & Retained on 16mm IS Sieve
- Passing 16mm IS Sieve & Retained on 12.5mm IS Sieve
- Passing 12.5mm IS Sieve & Retained on 10mm IS Sieve
- Passing 10mm IS Sieve & Retained on 6.3mm IS Sieve
- Take test sample (Minimum number of 200 pieces ) on any fraction to be tested.
- Weigh the sample on each sieve fraction
- Pass the sample of each fraction (Each piece) through respective sizes on thickness gauge.
- Weigh the sample passed in each size of the thickness gauge and Note it.
Flakiness Index (%) = 100x (Total weight of sample passed in each size of thickness gauge / Total weight of sample )
- Collect all material retained on thickness gauge
- Note the weight of each size fraction.
- Pass the pieces on each fraction through respective sizes in the length gauge manually.
- Weigh the sample passed in each size of the length gauge and note it.
Elongation Index (%) = 100x Total weight of sample retained in each size of length gauge / Total weight of sample gauged (i.e retained on thickness gauge)
Combined Flakiness & Elongation Index (%) = Flakiness index (%) + Elongation index (%)
Read more :
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- Method of Impact value test of aggregate
- Method of ten Percent fine value of Coarse Aggregate
- Method of crushing value test of aggregate
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