For determination of flakiness index of coarse aggregate, where the size of the coarse aggregate are larger than 6.3mm .
IS : 2386 (Part I) – 1963 – Method of test for aggregates for concrete (Part I) Particle size and shape.
Equipment & Apparatus
- Thickness gauge
- Sieves [63, 50, 40, 31.5, 25, 20, 16, 12.5, 10 & 6.3mm]
- Balance [0-10 kg]
Surface dry samples is used for the test. A minimum number of 200 pieces of any specified fraction is required to do the test.
- The sample is sieved through IS sieve specified in Table shown below.
- A minimum of 200 pieces of each fraction is taken and weighed.
- In order to separate flaky materials, each fraction is then gauged individually for thickness on a thickness gauge.
- The total amount of flaky material retained by the thickness gauge is weighed to an accuracy of 0.1% of the weight of sample.
In order to calculate the flakiness index of the entire sample of aggregates, first the weight of each fraction of aggregate passing and retained on the specified set of sieves is noted (Y1, Y2, Y3, Y4…..etc). Each piece of these are tried to be passed through the slot of the specified thickness of the thickness gauge are found and weighed (y1, y2, y3, y4…etc). Then the flakiness index is the total weight of the material retained on the various thickness gauges, expressed as a percentage of the total weight of the sample gauged.
Flakiness index is reported in percentage to the nearest whole number
Safety & Precautions
- Use hand gloves while removing containers from oven after switching off the oven.
- Use safety shoes, mask & aprons at the time of test.
- Thoroughly clean & dry the container before testing.
- Special care should be taken that no outer air enters when using the balance.
- All parts of the equipment should always be kept clean.
- After the end of the test sieve should be clean by smooth brush.