Page 45 - HIGHWAY ENGINEERING LABORATORY_FLIP BUILDER

3.0 EQUIPMENT :

Thermometer

Support Frame
(Shouldered Brass Ring)

Heat Resistance
GlassBeaker

Stainless Tapered Ring
SteelBall

Stop Watch Spatula

4.0 DETAILED PROCEDURE : AGGREGATE IMPACT VALUE

REFERENCE
WORK PROCESS
DOCUMENT
1. Specimens are prepared in precisely dimensioned brass rings

and maintained at a temperature of not less than 10°C below
the expected softening point for at least 30 minutes before the
test.
2. The rings and assembly, and two ball bearings, are placed in a
liquid bath filled to a depth of 105 ± 3 mm and the whole

maintained at a temperature of 5 ± 1°C for 15 minutes. (Freshly
boiled distilled water is used for bitumen with a softening point
of 80 °C or below, and glycerin is used for softening point

greater than 80°C).
3. A 9.5 mm steel ball bearing (weighing 3.50 ± 0.05 g) is centered
on each specimen and heat is then applied to the beaker so as
to raise the
4. temperature by 5 ± 0.5 °C per minute.

5. The temperature at which each bitumen specimen touches the
base plate is recorded to the nearest 0.2°C.

Higway Engineering Laboratory page 32