Porous asphalt mixture is conventional hot mix asphalt (HMA) with substantially decreased ines,
which produces an open-graded mixture that enables the water to low through an interconnected
void space. Porous asphalt is a permeable system that has a lot of beneits. However, because of its
open structure, the durability of this mixture decreases, and both its stability and resilient modulus
are much lower compared to the dense conventional asphalt mixtures. Also, the high void percentage
may lead to an increase in the draindown proportion. Fibers (cellulose or mineral) and polymermodiied
binders
are
recommended
for
porous
asphalt
mixtures,
especially
in
hot
and
moderate
climates.
The
objective
of
this
study
is
to
improve
the
porous
asphalt
mixture’s
performance
by
using
ethylene–vinyl
acetate
(EVA)
polymer-modiied
bitumen.
Two
types
of
ibers
(cellulose
ibers
and
glass
wool
ibers)
were
used,
separately
to
determine
the
control
mixture.
Four
diferent
proportions
of
EVA
polymer
were
added
to
the
bitumen
(1%,
2%,
3%,
and
4%)
and
Scanning
Electron
Microscopy
(SEM)
was
used
for
better
investigating
of
the
bitumen
microstructure,
then
The
Marshall
mix
design
was
used
to
determine
the
optimum
EVA
content
(OEC)
for
the
porous
asphalt
mixture.
Several
performance
tests
were
conducted
to
investigate
the
characteristics
of
the
porous
asphalt
mixture,
such
as
the
iniltration
rate,
binder
draindown,
the
wheel
track
and
the
cantabro
abrasion
tests.
The
indings
of
the
study
conclude
that
the
addition
of
EVA
polymer
to
the
porous
asphalt
mixtures
enhances
the
performance
as
it
increases
stability
by
20.8%
and
the
iniltration
rate
by
20.6%.
It
decreases
binder
draindown
proportion
by
33.3%,
cantabro
abrasion
loss
by
25.1%
and
the
rut
depth
at
5,000
cycles
and
10,000
cycles
by
29.8%
and
19.7%,
respectively |
