The document describes the Marshall method of determining the optimum binder content for a bituminous mix design. Aggregates and binder are heated and mixed to different binder contents. Specimens are compacted with blows from a hammer and tested for properties like flow value, stability, and density. Graphs are made plotting these properties against the varying binder contents. The optimum binder content is determined as the percentage where the graphs show highest stability and density and lowest flow value.

1. BITUMINOUS MIX DESIGN
BY MARSHALL METHOD
• Aim of the experiment : To determine the
optimum binder content of given bituminous
mix by Marshall method of mix design.

2. Apparatus required :
Compaction mould , Cylindrical mould of
diameter10.16cm and height of 7.5cm with collar
, and a base plate .
Compaction hammer , The compaction hammer
has a flat circular plate of diameter 98.4mm and
weight 4.5 kg lifted and released from a height of
45.7 cm
The compaction pedestal , thermometers, oven
and Dialguages.

4. Procedure :
 coarse aggregates , fine aggregates and mineral
filler materials are mixed in the design proportion
to meet the designed gradation as per Morth.
The Bitumen content to be used for the mix as per
the IRC standards or Morth.
Exactly 1200 gms of materials are taken and
heated to a temperature of 175 to 190 degree
celsius. Then the required quantity of Bitumen is
heat upto 120 to 165 degree celsius.

5. The compaction mould is also preheated to a
temperature of 95 to 150 degree celsius . The
Bitumen the aggregates are mix thoroughly by using
a mechanical or hand mixers and recommended
temperature depends on grade of Bitumen.
The Bitumen mix is placed in a mould and
compact it with a standard hammer with a height of
drop 45.7cm by applying 75 blows on each side.
The specimen is allowed to cool at room
temperature , the weight , average thickness and
diameter of the specimen are noted . The specimen
are weighed in air and also suspended in air.

6. The specimen to be tested is kept immersed
under water in a thermostatically controlled water
bath maintained at 60 degree celsius for 30 to 40
minutes.
Specimen is taken out from water bath and place
it under the loading frame at the rate of
51mm/minute.
The load and deformation reading are noted and
the maximum load is express in kg and the
deformation is expressed as flow value.

7. 0
1
2
3
4
5
6
7
0 1 2 3 4 5 6
flow valve
(mm)
% of Bitumen
0
10
20
30
40
50
60
70
80
90
0 1 2 3 4 5 6
VFD in %
% of Bitumen

8. 0
1
2
3
4
5
6
7
0 1 2 3 4 5 6
volume of
voids
% of Bitumen
0
200
400
600
800
1000
1200
1400
0 2 4 6
Marshall
stability in
kg
% of Bitumen

9. Result : The optimum binder content of
the given mix is _______.
0
0.5
1
1.5
2
2.5
0 1 2 3 4 5 6 7 8
M
a
x
i
m
u
m
d
e
n
s
i
t
y
(
g
/
c
c
)
% of B itumen