04.
Introduction This method is based on the classification of aggregate particles as flaky when they have a thickness (smallest dimension) of less than 0.6 of their nominal size, this size being taken as the mean of the limiting sieve apertures used for determining the size fraction in which the particle occurs. The flakiness Index of an aggregate sample is found by separating the flaky particles and expressing their mass as a percentage of the mass of the sample tested.
Discard all aggregate retained on the 63.0 mm BS test sieve and all aggregate passing the 6.30 mm BS test sieve. Then weigh each of the individual size-fractions retained on the sieves, other than the 63 mm BS test sieve, and store them in separate trays with their size marked on the trays. Where the number of particles in any size fraction is considered to be excessive i.e. more than the appropriate mass given in Table 1, the fraction may be subdivided by standard methods.
Table 1. Dimensions of Thickness Gauge. Aggregate Size-fraction BS Test Sieve Nominal Aperature Size 100% Passing 100% Retained Thickess Gauge Width of Slot Minimum Mass for Subdivision 63.0mm 50.0mm 33.9 ± 0.3mm 50kg 50.0mm 37.5mm 26.3 ± 0.3mm 35kg 37.5mm 28.0mm 19.7 ± 0.3mm 15kg 28.0mm 20.0mm 14.4 ± 0.15mm 5kg 20.0mm 14.0mm 10.2 ± 0.15mm 2kg 14.0mm 10.0mm 7.2 ± 0.1mm 1kg 10.0mm 6.30mm 4.9 ± 0.1mm 0.5kg Warranty Humboldt Mfg. Co.
