Page 28 - HIGHWAY ENGINEERING LABORATORY_FLIP BUILDER

REFERENCE
WORK PROCESS
DOCUMENT

SAMPLE

Use the material retained on any of the following sieves: 50, 37.5,
28, 20, 14, 10, 6.3mm sieve and has been placed into separate
containers.

Aggregates retained on each sieve which comprises at least
5 percent of the total sample, shall be tested.

INSTRUCTION

a) Wash and ovendry samples toaconstant weight at 110 ± 5 °C
(230 ± 9°F)
b) Sieve an aggregate amountof 2 kg using the BS Standard sieves
asoutline inTable1

Table 2.1: BS test sieves sizes for flakiness index test
c) Test each of the particles in each size fraction using the proper slot
opening for each sieve size.
d) Separate theparticles passing throughthe slot from those that
do not pass through the slot.
e) Weight the particles passing the slot to the nearest 0.1 gram.

CALCULATION FOR AN INDIVIDUAL SIEVVE SIZE

Flakiness Index (FI) = Weight pass slot x 100
Weight Original

% Flakiness Index = A x 100
A + B
Where:
A = Weight passing a given slot
B = Weight retainedonthesame slot

Higway Engineering Laboratory page 15