Flakiness & Elongation of Aggregate

Determinations for the flakiness index and flakiness and elongation of aggregate use a British Standard classification system consisting of a Thickness Gauge for determining flakiness index and a metal Length Gauge for determining elongation index. Aggregate is separated into seven sieve fractions from 63—6.3mm and each fraction is evaluated separately.

Test aggregates must be sieved using sieves with openings of 63, 50, 37.5, 28, 20, 14, 10, and 6.3mm. These are available as 200mm diameter brass frame sieves with stainless steel cloth as ISO Test Sieves.


Thickness Gauge (Flakiness Index)
Models: HM-925, HM-924
Flakiness and Elongation Index of Aggregates
  • Thickness Gauge (Flakiness Index) is a slotted stainless steel gauge for rapid hand trying of particles from the seven sieve fractions to determine the flakiness index.
  • Length Gauge (Elongation Index) has six labeled openings between metal pins for measuring the length of particles from each of the six sieve cuts below 50mm, for elongation index determinations.

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