CALCULATION OF AIV

1. Created by Shahryar & CO.

2.  This test is done to determine the aggregate impact
value of coarse aggregates
 AIV is basically a % ratio of 2.36mm sieved aggregate
to 14mm aggregate sieve.
 The apparatus used for determining aggregate impact
value of coarse aggregates is
 Impact testing machine Sieves of sizes – 14mm, 10mm
and 2.36mm,a cylindrical metal measure of 75mm
diameter and 50mm depth, A tamping rod of 10mm
circular cross section and 230mm length, rounded at
one end.

3. It is usually used
to tamp the
aggregate so
that it should
acquire all the
empty space of
metallic cup. Its
diameter is
10mm and it is
230 mm in size .
Tampin
g Rod

4. A sample of
aggregate
containing
element of
different
sizes for the
experiment.
Coarse
aggrega
te

5. Sieves of
sizes
14mm,10m
m and
2.36mm
must be
available.
Sieves of
Differen
t sizes

6. A cylindrical
cup of
diameter
75mm and
cross
section
30mm
length.
Cylindri
cal Cup

7. A digital weight
calculation
machine is also a
part of the
experiment.
Weight
Calculating
Machine

8. An average aiv machine
must have following
properties
1-mass variable up to 13.6
kg
2-impact energy variable
up to 132.8 J
3-impact velocity up to
4.4 m s
4-its hammer diameter is
70mm
AIV
Calculating
Machine

9.  First of all set all the sieves according to the following order:-
 14mm>10mm>2.36mm or 14mm sieve on the top and 2.36 sieve at the
bottom.
 Pass the given amount of aggregate through the sieves according to
given order.
 Collect the aggregate which passes through 14mm sieve and retained
on 10mm sieve. This aggregate is known as Coarse aggregate.
 Take the metallic cup and weight it .Let its weight is W.
 Now fill 1/3 of the cup with coarse aggregate and tamp it with at least 25
tamps of tamping rod. Repeat the whole procedure 3 times so that all
the empty space of cup should be completely filled with aggregate.
 Weight the cup let it must be W1
 Carefully place the cup beneath the hammer of the aiv machine.
 Hammer it with 15 strokes of machine hammer.
 Pass the retained aggregate through 2.36 sieve.
 Calculate the weight of passed aggregate let it be W2

10.  After calculation we can find aiv % by given formula
 AIV % = (W1-W/W2) x 100
 APPLICATION S OF AIV
 Aggregate having AIV % less 50% is better to use in
construction where as those having value more than 50%
are bad for construction.
 It is reliable to calculate the AIV % of the aggregate use as
road metal as it will give us the capacity of road to bear the
load on it. Aggregate having AIV % equal or greater than 35
% is considered bad to use in road construction.