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Procedure for Flakiness Test:
1) The sample of aggregate to be tested is first sieved through a set of sieves and separated into specified size ranges. Now to separate the flaky material, the aggregates which pass through the appropriate elongated slot of the thickness gauge are found.
2) The width of the appropriate slot would be 0.6 of the average of the size range. If the selected size range of aggregate in a group is 20 – 16 mm (i.e., passing 20 mm and retained on 16 mm sieve), the width of the slot to be selected in thickness gauge would be 18 x 0.6 = 10.8 mm.
3) The flaky material passing the appropriate slot from each size range of aggregate are added up and let this total weight of flaky particles be W1 gm.
4) If the total weight of sample taken from the different size ranges is W gm., the flakiness index is given by (W1/W) x 100 percent; in other words Flakiness Index(FI) is the percentage of flaky materials, the widths of which are less than 0.6 of the mean dimensions.
Procedure for Elongation Test:
1) The sample of aggregate to be tested is first sieved through a set of sieves and separated into specified size ranges.
2) The longest side of aggregate particles from each of the size range is then individually passed through the appropriate gauge of the length gauge; the gauge length would be 1.8 times the mean size of the aggregate.
3) The portion of the elongated aggregate having length greater than the specified gauge from each size range is weighed.
4) The total weight of the elongated stones is expressed as percentage of the total of the sample taken to obtain the elongation index.