SHRP-A/UWP-91-510
Chemical Properties of Asphalts
and Their Relationship to
Pavement Performance
Raymond E. Robertson
Western Research Institute
Laramie, WY
Strategic
Highway Research Program
National Research
Council
Washington, D.C. 1991
SHRP-A/UWP-91-510
Contract A-002A
Product Code 1001, 1007
Program Manager: Edward T. Harrigan
Project Manager: Jack S. Youtcheff
Program Area Secretary: Juliet Narsiah
March 1991
Reprinted November
1993
key words:
adhesion
aging
asphalt
chemical mode
failure models
fatigue cracking
imermolecular
metals
moisture damage
oxidation
pavement performance
permanent deformation
polarity
rutting
thermal cracking
virgin asphalt
Strategic Highway Research Program
National Research Council
2101 Constitution Avenue N.W.
Washington,
DC 20418
(202) 334-3774
This manual represents the views of the author only, and is not necessarily reflective of the views of the
National Research Council, the views of SHRP, or SHRP's sponsor. The results reported here are not
necessarily in agreement with the results of other SHRP research activities. They are reported to stimulate
review and discussion within the research community.
50/NAP/1193
Acknowledgments
The research described herein was supported by the Strategic Highway Research
Program (SHRP). SHRP is a unit of the National Research Council that was authorized
by section 128 of the Surface Transportation
and Uniform Relocation Assistance Act of
1987.
This project was conducted by the Western Research Institute in cooperation with the
Pennsylvania Transportation Institute, the Texas Transportation Institute, and SRI
International.
Raymond E. Robertson was the principal investigator. The support and
encouragement of Dr. Edward T. Harrigan, SHRP Asphalt Program Manager, and Dr.
Jack Youtcheff, SHRP Technical Contract Manager, are gratefully acknowledged.
The experimental work cited herein was conducted by Dr. J. F. Branthaver, Dr. K.
Ensley, Dr. J. Duvall, H. Plancher, P. M. Harnsberger, S. C. Preece, F. A. Reid, J.
Tauer, M. Aldrich, A. Gwin, M. Catalfomo, G. Miyake, and J. Wolf. Their support in
the preparation of this report is gratefully acknowledged.
The review of this manuscript
by Dr. J. Claine Petersen, former principal investigator for A-002A; Dr. Jan F.
Branthaver at WRI; and Dr. David Anderson at PTI, co-principal investigator for
A-002A; and Dr. Edward T. Harrigan and Dr. Jack Youtcheff of SHRP is hereby
acknowledged.
°°°
nl
Contents
1.0 Introduction ...................................................
1.1 Objectives of the SHRP Asphalt Program ........................
1.2 Purpose of Report
.........................................
1
1
2
2.0 Chemistry
....................................................
2.1 Molecular Level ...........................................
2.1.1 Typical Species in Virgin Asphalt ........................
2.1.2 Oxidation to Form New Molecules .......................
2.1.3 Metals ............................................
2.1.4 Polarity ...........................................
2.2 Intermolecular Level ......................................
2.3 Chemical Mode of Asphalt ..................................
3
3
3
5
9
9
10
17
3.0
Speculation on Relationship of Chemistry to Pavement
Performance ................................................
3.1 General Comments
.......................................
3.2 Aging .................................................
3.3 Speculation on the Relationship of Composition
to Various Failure Models .................................
3.3.1 Rutting and Permanent Deformation .....................
3.3.2 Thermal and Fatigue Cracking .........................
3.3.3 Adhesion and Moisture Damage ........................
4.0 Summary
....................................................
20
20
21
23
24
25
26
29
V
List of Structures
1
Molecular Fragment
of an Aliphatic
2
Molecular Fragment
3
........................
4
of an Aromatic Hydrocarbon
........................
4
Molecular Fragmem
of an Aromatic Hydrocarbon
........................
4
4
Molecular Fragment
of an Aliphatic and Aromatic Hydrocarbon
5
Molecular Fragmem
of a Pyridine
6
Molecular Fragmem
of a Thiophene
7
Molecular Fragmem
Showing Benzyl Carbon
8
Molecular Fragmem
of a Ketone
9
Molecular Fragmem
of a Carboxylic Acid ..............................
6
of a Sodium Carboxylate
7
10 Molecular
Fragmem
Hydrocarbon
...................................
..................................
...........................
....................................
...........................
..........................
.............
4
5
5
6
6
11 Molecular Fragment
of a Calcium Carboxylate
12 Molecular Fragment
of a Carboxylic Anhydride
13 Molecular Fragment
of a Phenol
14 Molecular Fragment
of a Homolog
..................................
8
15 Molecular Fragment
of a Homolog
..................................
8
.........................
....................................
vii
7
7
7
16 Molecular Fragment of a Homolog
..................................
8
17 Molecular Fragment of a Quinolone ..................................
8
18 Molecular Fragment of a Sulfoxide
9
19 Metalloporphyrin
..................................
...............................................
Vll"1""
9
List of Figures
1A
Randomized
1B
Organized
2
Three Dimensional
3
S.E.C. Chromatograms
4
Effects of Temperature on Aging Kinetics of an Asphalt Sensitive
to Molecular Structuring
.......................................
17
Performance
21
5
Molecules
Molecules
°
.........
°
°
•
•
Molecular
•
°
•
•
•
°
•
" "
" *
" " .........
°
•
•
•
•
°
°
•
•
•
°
°
•
•
•
•
°
..............
• •
•
•
10
•
Matrix ..............................
........................................
................................................
ix
•
•
•
•
•
•
.
o •
o
10
11
14
S_Y
F,_C_ZVE
The
chemistry
of
intermolecular
levels
interpretation
and
performance
thousands
of
asphalt.
Asphalts
vary
widely
this
portion
asphalts
strongly
matrix
polar
to
gives
phase
These
polar
form
elastic
gives
while
little
cement
zones
by
the
to
to
adds
binder.
to
leads
the
age
additional
At
very
low
xi
less
of
contributor
to
and
which
which
materials
any
the
chemical
a
set
of
the
It
of
of
of
asphalt.
and
of
polar
continuous
materials
non-polar
involvement
while
to
associate
among
assemblage
cements
of
properties
nature
temperature
that
objective
polar
exact
hardening
polar
tend
The
to
particular
species
major
by
asphalt
to
very
arise
the
brittle
a
may
non-polar
of
characteristics
structuring
the
any
major
structural
overall
component
leads
contributing
within
the
structuring
Oxidation
or
explain
hundreds
molecular
The
materials
in
may
level
within
behavioral
dispersed
data
least
of
Polar
within
viscous
at
of
molecular
exist
intermolecular
character
a
that
combination
the
is
species.
a matrix
are
and
chemical
Polarity
mechanical
than
a
weight.
interactions
important
structuring
stress.
the
and
At
explain
is
chemical
excessive
too
to
the
to
less
materials
is
molecular
comprised
molecular
which
general,
different
is
be
chemistry.
related
components.
numerous
work
of
to
the
how
there
species
and
a matrix
In
are
that
known
on
roadways.
characteristics.
into
materials.
are
terms
in
at
herein
placed
molecular
the
performance
specie
discussed
shown
polarity
of
in
have
unique
in
asphalt
speculation
studies
asphalt
is
characteristics
historical
the
petroleum
polar
medium.
The
continuous
is
non-
speculated
tends
to
deform
brittleness
to
the
it
appears
that
crack
under
of
asphalt
structured
that
of
the
non-polar
and
materials
that
this
speculated
A
rigid
that
temperature
methods.
by
develop
producers
of
personnel
both
with
Certainly
to
is
any
is
should
test
and
give
for
new
test
another
largely
rigid
material,
It
is
responsible
asphalt
method
will
for
low
on
The
that
asphalts
that
the
worked
test
to
methods
they
closely
direction
in
each
arise
as
become
Problems
robin
of
when
test
robin
xii
conunon
are
with
there
is
and
to
effort,
of
and
contractor
maintain
a
to
how
much
of
new
test
methods.
complex,
but
no
in
in
problem
a
sector.
more
considers
program
in
SHRP
implementation,
one
economic,
perform
users
extraordinarily
that
so
and
will
both
implementation
assure
round
current
program,
program
could
round
fashion
of
the
espec'ially
a
identifying
technical
for
enter
into
employed
both
be
and
been
work,
questions
to
on
same
implementable
required
have
methods
characteristics.
development
methods
laboratories.
the
have
advice
research
emphasis
alleviating
necessary.
minimized
in
Throughout
objective
be
an
selection
practically
absolutely
user
a very
temperature.
methods
of this
thereby
will
new
still
low
translate
performance
advantages
petroleum
what
with
asphalts
failure.
specialization
than
their
fashion
road
As
into
is
research
asphalts
methods
premature
of
at
shrinkage
is to
of
among
expected
predictable
sense
of
types
distinguish
to
type
organize
shrinks
objective
among
distinguished
is
this
major
differentiate
are
to
material
Numerous
The
tend
cracking.
second
which
also
both
fact,
it
complexity
therefore,
that
each
state
has
new
highway
already
begun.
Finally,
this
results
that
implemented
are
work
is
supported
into
new
domain.
xiii
by
test
public
funding
methodology
and
will
be
the
public
1.0
i.i
Objectives
The
of
SHRP
ultimately
be
known
vacuum
asphalts
and
as
this
a mix
they
than
are
a
of
using
classified
in
the
It
behooves
binders
which
no
are
have
doubt
asphalts
a
set
pavements
of
various
the
user,
reflected
types
therefore,
in
desirable
petroleum
that
have
there
of
viscosities
residua
desirable
to
is
be
used
at
material.
Yet,
vary
quite
have
early
been
failures
determine
performance
properties.
will
or
two
no
performance
must
develop
the
refiner's
distinction
elevated
That
AC-20,
their
and
is,
all
all
will
The
rude
surprises
and
with
what
and
costly
increasing
properties
then
a
be
practical
to
results
frequency.
of
select
modification
characteristics.
of
performance
significantly.
From
require
in
petroleum
for
susceptibility.
example,
to
for
little
mixtures
properties
exercise
for
to
pavement
performance
many
of
and
material
control
hence
asphalts
binders
are
which
asphalt-aggregate
specifications
quality
often
endeavor
and
both
properties
current
focused
binders
fundamental
as,
single
highly
of
oxidation
classified
in
form
a
plant
characteristics
poorly
a
for
the
The
than
be
is
performance
operations,
may
if
area
fundamental
other
asphalts
applied
the
more
tower
temperatures
many
Then
little
crude
among
to
specifications.
are
Program
specifications
accomplish
first.
meaningful
asphalt
relate
To
Asphalt
research
develop
that
pavements.
SHRP
asphalt
must
mixtures
the
INTRODUCTION
asphalt
binders
viewpoint,
prepare
1.2
Purpose
The
SHRP
of
purpose
chemical
to
correlate
of
some
performance
the
non-chemist
of
the
the
between
the
chemical
studies
are
to
composition.
This
for
a
given
the
manufacture
of
the
producer
to
another.
will
distinguish
the
References
SHRP,
but
based
on
in
many
current
which
in
not
If
It
any
is
is
correlate
with
obvious
properties
that
are
to
research
cases
SHRP
has
research
ongoing
not
been
and
do
no
composition
to
the
a
producer
it
asphalt
many
is
in
compositional
the
that
describe
composition
deficiencies
so
and
vary
from
chemical
a major
goal
to
relate.
which
published.
have
has
note
performance
the
to
modify
tests.
correlations
acceptable
that
to
chemical
made
to
pavement
performance-
methods
asphalt
to
property
develop
of
how
important
that
instructive
given
become
with
Further,
definition
turn
of
asphalts
the
be
effort
physical
to
to
of
speculative
analytical
determine
has
is
practical
allow
It
mainly
status
intended
believed
properties.
will
can
be
studies
of
a
generally
will
physical
set
is
current
is
properties
is
binders
asphalt.
deficiency.
asphalt
properties
then
performance
deficiency,
the
a
the
It
further
chemical
It
and
describe
asphalt.
composition
define
to
and
known
for
of
is
petroleum
characteristics.
objective
remedy
report
of
specifications
The
one
this
studies
instructive
based
Report
has
Many
literature
been
reported
statements
references.
are
to
2.0
It
is
convenient
two
parts.
The
the
second
part
species
first
is
in
species
molecular
and
chemistry
of
techniques
2.1
Molecular
reviewed
is
research
done
by
essentially
2.1.1
most
of
variety
of
materials),
many
molecular
asphalt
can
or
matrix
in
units
is
what
the
both
types
of
the
the
the
program.
composition
at the
reference
"building
asphalt
reference
SHRP
be
of molecular
without
among
with
best
subsection
reviewed
interaction
and
within
at
following
subsection
total
high
mass
are
have
molecular
fragments
type).
both
for
material
of
boiling
some
petroleum
workers
Species
molecules
(aromatic
the
level
all
asphalt
illustrate
of
currently
on
textbook
Typical
the
used
assembly
level
is to
second
of
into
to
some
of
Level
Extensive
been
In
molecular
the
among
examine
asphalt
molecular
multi-molecular
to
chemistry
in
the
nature
as an
large
This
The
being
physical
levels.
methods.
at
petroleum
interaction
exist
the
of
chemistry
of
into
at
present.
the
chemistry
composition,
techniques
asphalt
is
the
the
intermolecular
experimental
molecules
of
of
blocks)
Numerous
are
is
the
chemistry
Much
terms
asphalt.
has
the
(building
blocks"
divide
part
in asphalt.
described,
to
to
CHEMISTRY
many
but
worth
in Virqin
neat
aromatic
(more
aliphatic
and
are
in
shown
At
At
asphalt
Some
like
this
reviewing
Asphalt.
(tank)
hydrocarbons.
years.
is
are
Structures
level
much
of it
here.
the
molecular
of
aliphatic
carbon.
1
point,
a mixture
air-blown
aromatic
molecular
a wide
(waxy
asphalts)
Examples
(aliphatic
level
type)
and
of
some
such
and
2
H
I
H
I
H
I
H_ C_"C" C_"C"c/C_
_CH2_ICH2_x_CH3
_
_
x Typically
Structure
1 and
that
make
carbon
= 15 or More Carbons
Structure
1
2 is
commonly
3 are
up
more
only
carbon
represented
representative
but
chains
in
which
4 shows
a molecule
Structure
fragments
1 is
shown
as
there
are
Structure
typically
by
molecular
asphalt
have
one
Structure
Structure
II
I
_c_C_H
I
H
Structure
asphalts.
atoms,
aliphatic
I
I
HIC-_c/C_c/C
I
I
H
H
which
is
or
more
a
3.
of
straight
numerous
2
Both
larger
C/
structures
molecules
chain
of
combinations
branches.
3
a mixture
of
aliphatic
and
aromatic
carbon.
2
____CH
2 (CH)x-CH3
Structure
While
the
molecules
major
mass
also
contain
of asphalt
one
or
4
is hydrocarbon,
more
heteroatoms;
4
of
a large
nitrogen,
proportion
sulfur,
of
oxygen
and
metals.
Nitrogen,
in
the
form
of
a
pyridine
CH2-(CH2)x"Structure
Sulfur,
as
right
is
a
identical
a
benzothiophene,
shorthand
is
notation
molecular
in
the
shown
in
Structure
5.
CH 3
5
shown
of
is
Structure
one
to
6.
the
Structure
left.
These
6 on
the
are
fragments.
H
I
--H
or
/
Structure
Both
sulfur
molecules.
and
nitrogen
Hence,
molecular
species
different
arrangement
also
follows
molecular
to
2.1.2
asphalt
may
that
any
species
classify
are
the
it
may
is
easy
be
present
of
elements
be
chemistry
susceptible
to
definition
would
Oxidation
appear
to
Form
to
in
that
in
asphalt
of
terms
Molecules.
oxidation.
An
of
a
task.
the
variety
of
based
on
It
much
Certain
aliphatic
is
of
that
different
molecular
sites
thousands
considering
properties
of
a
tens
constitutes
of
New
any
see
a monumental
in
6
within
different
every
molecule.
It
specific
more
effective
types.
types
carbon
of
next
carbon
to
in
an
aromatic
ring
oxidizable
showing
is
known
site.
as
a benzyl
Structure
a benzyl
carbon
7
in
is
bold
carbon
an
and
example
type
is
of
an
example
a molecular
(adjacent
to
the
of
a
readily
fragment
aromatic
ring).
CH2-(CH2)x
Structure
Sites
such
as
these
oxidize
to
form
7
ketones
as
shown
in
Structure
8.
C_(cH2)x--
Structure
More
severe
loss
of
Structure
oxidation
part
of
the
may
molecule
result
in
such
8
formation
as
shown
of
by
both
carboxylic
acids
versions
and
of
9.
°r
Structure
Carboxylic
acids,
whether
oxidation,
may
converted
be
present
to
in
sodium
9
the
original
(Na)
salts
crude
or
(Structure
formed
10)
upon
or
calcium
(Ca) salts
calcium
inorganic
upon
rings.
An
by
appropriate
reaction
with
O
O
O
II
II
II
i0
acid
oxidation
11)
sodium
or
compounds.
Structure
Carboxylic
(Structure
Structure
anhydrides
when
example
two
is
(typically
benzyl
called
carbons
Structure
are
anhydrides)
present
11
may
on adjacent
be
formed
aromatic
12.
0% c/O_c//0
(CH2)xCH3
Structure
Another
asphalt
an
type
is a class
aromatic
ring.
of
oxygen
known
This
as
containing
phenols
class
is
12
molecule
where
oxygen
illustrated
by
which
x'- CH2,_CH
Structure
7
13
be
is attached
Structure
OH
CH3-(CH2)
may
3
13.
present
directly
in
to
Again
may
numerous
exist.
shown
above,
homologous
variations,
In
addition
homologs
series
or
to
of
is
isomers,
isomeric
each
shown
combinations
also
by
containing
typically
Structures
14,
the
of
basic
all
exist.
An
15,
16.
and
phenol
molecular
example
unit
types
of
a
0
II
-C_cH2
--
Structure
14
Structure
15
Structure
16
(CH2) x CH3
O
II
C_cH2--(CH2)x+I-CH3
O
II
C_cH2--(CH2)x+2--CH3
In the
above
case,
unique
molecule,
each
varies
although
the
only
by
one
properties
aliphatic
among
all
carbon.
of
these
Each
will
similar.
Another
asphalts
is
important
quinolones
class
as
of
shown
compounds
in
typically
Structure
Structure
17
17.
found
in
aged
be
is
a
quite
Many
sulfur
typically
form
Structure
18.
compounds
are
sulfoxides.
also
A
susceptible
sulfoxide
to
containing
structure
Metals.
varying
amounts
nickel,
and
metals
are
There
and
although
present
as
An
also
metals
example
is
shown
present
most
may
organo-metallic
in
CH3CH 2
asphalts,
common
also
Structure
metals
be
materials,
by
shown
in
again
in
18
The
other
is
2-
metals
distributions.
iron
porphyrins.
are
and
fragment
O
II
-(CH2)xCH2-S-CH2-CH
2.1.3
oxidation
are
present.
vanadium,
Typically
specifically
as
19.
H
CH3
H
CH2CH3
CH3@__CH2CH3
3NZ'N(
cH cH2
CH3
Structure
By
may
forth
be
now
it
found
in
asphalts
2.1.4
nitrogen,
is
any
will
Polarity.
sulfur,
obvious
given
that
contain
All
oxygen,
and
the
of
thousands
Further,
hundreds
of
19
hundreds
asphalt.
of
naturally
metals
H3
the
unique
second,
thousands
of
occurring
contribute
of
to
third
different
molecules
and
so
molecules.
heteroatoms,
polarity
within
these
molecules.
further
is
Likewise,
contribute
the
to
separation
following
of
example.
2.19
(C5H5 N)
is
benzene
(C6H 6) is
Polarity
is
organize
themselves
these
terms
have
the
asphalt,
one
polar
dipoles.
in
into
been
within
all
as
phase)
because
orientations.
formations
of
A more
given
in
the
by
of charge)
of
the
moment
dipole
analog
to
of
which
pyridine
of
pyridine.
species.
cause
colloids,
molecules
to
these
etc.,
understanding
following
and
the
Historically,
micelles,
current
polar
Polarity,
seen
containing
tends
are
although
of molecular
Subsection.
Level
another
molecule
Figure
for
level,
behavioral
another
1 illustrates
polar
molecules
characteristic.
as
a result
this
of
including
This
their
is
1A
+)CFigure
10
those
IB
in
attraction
separated
schematically.
(Figure
it
be
carbon
heteroatom
preferred
is
can
whereas
all
aging
system.
(separation
is the
asphalt
asphalts
intermolecular
have
gas
upon
entire
a molecule,
other
misused.
formed
the
moment
Benzene
in
to
Intermolecular
At
(in the
important
referred
orientation
2.2
exists
of
within
dipole
zero.
products
polarity
charge
debyes
also
been
the
The
Polarity
have
oxidation
charges,
of
or
In
part
are
A
well
the
polar
oriented
with
stable
thermodynamic
little
difference
involved.
one
schematics
that
sort
that
within
from
the
of
the
the
charge
to
organized
each
is
many
polar
in
Figure
1A
or
although
(see
so
that
note
charges
For
at
combinations
charges
are
not
true
are
charges
intended
ends
of
plus
of
and
defined
minus
necessarily
as
a
this
as
convenient
in
The
terms
charges
the
requirement
It
is
is
illustrated
components
regularity
exists
other
of
as
end
illustration.
11
shows
positive
associations
short
be
to
and
among
range
asymmetric
would
distributed
-7
2
schematic
and
fill
molecular
specific
makes
molecules.
-)C+
molecules.
electrostatic
best
form
it
is
may
the
a more
earlier
primary
in
molecules
I).
-)C+
simplicity,
the
The
the
that
shown
individual
no
Figure
1)
here
G 0
0 0
C+
(Note
B.
may
the
note
B
represents
molecules
present
structure
part
B
molecules
polar
is
in
Part
to
of
next
zone
other.
types
2,
the
but
important
separation
Figure
one
randomized,
many
a multi-molecular
in
vary
of
It
shown
of
schematically
will
to
state.
molecular
obvious
are
respect
which
Any
some
molecules
molecules
forces.
electron
the
end.
case
The
density
with
Figure
negative
ions.
2
is
only
are
actual
and
are
Neither
During
the
organization,
structure
forms.
colloid.
While
molecules.
to
it
is
set
not
shown
molecules.
The
structure
short
range
forces
Short
range
(non-covalent)
while
covalent
bonds,
greater
Kcal/mole
Kcal/mole.
may
be
or
changing
by
to
When
the
each
other
the
organized
Said
differently,
more
viscous,
assembled,
upon
the
structure
number
Oxidation
oxidation
formed
to
occurs,
in
larger
self-associate
of
to
covalent
has
stronger.
that
hold
For
the
temperature.
than
physical
has
more
are
The
upon
where
that
than
will
increase.
more
the
to
in
on
are
greater
the
virgin
Also,
12
a
of
the
or
the
asphalt.
rate
of
the
to
more
deformation.
material,
organized,
attractions
or
selfand
occur.
organized
polarity
remain
The
attractions
the
without
respect
springlike
an
i00
different.
with
motion
form
strengths
effect
species
be
structure.
are
So
or
physical
occur
organized.
of
80
structure
from
will
about
to
more
ability
are
typically
either
will
move
intermolecular
pronounced
amounts
is
are
this
resistance
asphalt
Kcal/mole,
carbon-carbon
molecular
can
I0
together,
scrambled
properties
they
to
bonds.
(intermolecular)
the
they
when
sites
of
3
bonds
However,
All
stiffer.
new
be
other
chemical
molecules
organized
may
and
comparison,
organic
or
the
about
covalent
that
depends
a
from
as
randomized
compared
randomized,
sites
only
weak
structured
is
is
of
structure
are
structure
and
it
or
set
organizational
where
range
micelle,
organized
electrostatic
hand,
easily
an
by
then
are
is
the
together
composition.
molecules
called
held
much
its
other
more
IA
rearrangement
raising
it
preferred
carbon-hydrogen
follows
molecular
On
highly
It
been
intermolecular
is
bonds
and
subject
stress
same.
the
has
some
forces
are
three-dimensional,
micelle,
Figure
which
bonds
true
have
in
of
this
a
does
that
covalent
amount
Historically,
The
compared
some
formed
the
association
As
and
propensity
depends
are
upon
the
number
stronger
the
force
of
to
associate.
a
to
years.
plant
stiffening
time
the
The
at
SHRP
association.
in
can
into
molecular
level.
work,
the
observed
to
double
in
a
system
that
if
they
will
SEC.
The
there
an
was
association.
used
varies
to
exist
SEC
profiles
and
being
used
(SEC)
AAM
one
over
a
did
sample
was
oxidation.
rates
and
without
studied
at
The
magnitudes
aggregate
at
the
noted
present
to
whether
causes
separates
shown
in
the
of
be
Figure
on
and
size
least
by
separated
are
(in
axes.
all
by
this
or
In
the
multi-
is
molecular
the
whole
an
associated
of
the
a
current
disturbance
apparent
SEC
case,
entity
possible
plots
same
separated
excluded
as
size
are
molecular
in
exclusion
the
M)
were
the
size
three
materials
molecules
3
K,
and
of
shows
molecules.
the
of
13
G,
three
at
asphalt
groups
therefore
size
another
is
plotted
separates
group
that
as
All
process
time
3 which
all
to
magnitude
present
Figure
asphalts.
not
asphalt
and
experiments,
associated
and
the
in
according
matters
one
type
(hereafter
SEC
SEC
from
determine
illustrated
associated
also
are
from
The
with
in
oxidation
the
it
value.
oxidation,
being
chosen
The
are
original
that
driving
viscosity
example,
storage,
protecting
high
viscosity
so
extended
the
the
program.
The
or
protected
while
petroleum
It
was
this
its
components
molecule
sample
temperatures,
is
fashion.
asphalts)
single
was
chromatography
same
by
For
after
be
classified
inhibited
The
greater
slow.
near
and
the
is
method
AAK,
is
attractions.
process
association
It
AAG,
the
are,
temperature
of
One
similarly
more
there
the
overall
asphalt
chromatography.
Asphalts
the
After
various
methods
exclusion
and
association
asphalt
degree
several
of
The
to
of
and
in
magnitudes
asphalt
returned
present,
the
anything.
mix
viscosity
of
few
contribute
heated
the
virgin
of
and
But,
Hence,
experiment,
not
sites
attractions
asphalt.
period
of
to
size
so
asphalt
fraction
group
by
of
the
SEC CHROMATOGRAMS
30
--O
AAM/_\
\
25
/'
_AAG
\
20
_//1_
I
I
15
,
"==
0
.,.
:
\
0
*_
u
/ f'\
10
(J
I
I
u_
I
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_a
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\
0
0
20
40
60
Large
Molecular
Size
80
100
120
Small
Molecular
Size
Fi 9ure 3
14
whole
the
asphalt
x-axis.
that
and
(the
right
these
two
of
the
The
asphalt
size,
a
on
G
a
three
has
side
are
of
amount
determination
in
K
largest
appear
large
to
be
was
are
comprised
of
many
of
plot)
molecules
in
have
molecules,
large
in
very
(to
behaves
dispersing
Often
as
right
of
a
and
show
called
"solvent"
agent.
It
is
M
is
the
these
a maltene
for
will
the
tend
the
behavior
are
fluid
molecules
phase,
polar
to
materials
reduce
15
are
K.
Upon
in
in
K
Asphalt
M
example,
will
three
by
asphalts
SEC.
Yet
similar.
the
molecules
necessarily
smaller
associated
portions
exchange
chromatography
vary
(SFC)
from
one
less-associated
association
weight
molecular
for
of
and
of
large
these
Ion
also
this
truly
less
plot).
more
a
does
large
ones
not
therefore
SEC
have
examined
three
is
whereas
that
all
These
and
the
when
amount
molecular
large
other
supercritical
that
does
as
of
note
Further,
small
dissociate,
the
size
reverse.
present
not
Note
molecular
however,
M
comprised
will
association.
the
M,
on
molecular
relatively
molecules
asphalts
polar
a
smaller
that
less
the
that
each
indicate
smaller
discovered
apparent,
the
(IEC)
to
is
the
vapor-phase-osmometry
whereas
from
within
little
chromatography
another.
would
are
used
else
different
effect
asphalt
been
temperature,
nothing
very
but
the
(left
tests
Another
which
it
large
Asphalt
species
by
in
Asphalt
bimodal.
K
asphalts.
is
is
size
virgin
almost
there
molecular
and
is
either.
not
multi-molecular
is
that
K
that
in
is
M
that
Asphalt
pyridine,
If
conventional
both
of
of
increase
dissociate.
of
it
or
are
fraction
in
The
an
plot).
fraction
molecules.
fraction
larger
material
examinations
species
small
is,
molecular
illustrated
indicating
size
significant
with
very
the
That
the
materials
bimodal
continuum.
the
a
and
significantly
intermediate
further
y-axis
will
of
have
asphalt
material
behave
as
the
polars.
a
to
At
of
this
point,
asphalt.
It
strongly
polar
continuous
upon
be
made
continuous
neutral
asphalt
that
It
G
the
has
be
amounts
example,
asphalt
before
any
Asphalt
K
should
already
This
The
in
being
the
pavement.
SHRP
as
After
G
had
temperature
18
an
was
pressure
only
with
of
G
viscosity
and
able
is
the
likewise
is
to
hours
aging
effect
raised
to
hours,
asphalt
while
K
jumped
to
17
significant
is
behavior.
For
oxidation
what
of
K
is
observed.
should
viscosity
observed
are
Upon
cooling
both
to
G
the
newly
had
an
the
more
polars
at
while
under
can
K
in
a
increase
rapidly
with
same
an
both
16
strongly
of
index
under
of
(measured
and
its
own
dominate
oxidize
When
the
atmospheric
the
60°C)
of
elevated
rapidly.
oxidation
its
pressure,
at
At
is
in
23.
at
conditions.
being
vessel
asphalt
oxidized
index
dissociated
K
method
pressurized
(140°F)
had
aging
another
aging
60°C
and
accommodate
in
by
long-term
(235°F)
G
530
asphalts
formed
been
oxidation
both
whereas
its
that
implies
properties.
Oxidation
simulate
temperature,
60°C,
curves
additional
physical
Oxidation
113°C
72
depend
the
which
dominate
raise
to
SEC
species
this
less
speculation
the
accommodate
and
and
has
of
for
from
that
observed.
of
index
its
occurs
studies.
a method
within
to
a
appears
chemistry
tolerate
reverse.
oxidize
asphalt
in
in
Some
molecular
able
to
change
polar
400
be
molecules
history.
materials
changes
be
polars
apparent
small
would
minor
to
is
description
dispersed
of
differing
it
polar
are
thermal
non-associated
should
be
the
fraction
that
propensity
studied
asphalt
First,
predominant
oxidation.
upon
phase.
and
G
major
and
that
association
of
polar
polars
The
integrated
containing
units
effects
large
a more
a material
organized
polars
expected
of
used
a
less
would
the
the
considering
be
phase.
of
on
worth
to
into
composition
can
is
appears
associate
and
it
products
behavior.
The
polars
in
asphalt
K
substantially.
While
at
on
The
the
trends
of
differing
temperatures,
increases
with
road
selection
service
been
rates
in
and
raise
observed
of
with
4 how
the
be
any
into
quite
asphalts.
given
viscosity
This
taken
viscosity
other
of
temperature.
must
the
oxidation
Figure
oxidation
temperatures
for
strongly
have
note
increasing
process
very
same
subject
different
maximum
associate
asphalt
change
indicates
account
that
in
the
asphalts.
EFFECTSOF TEMPERATUREON AGING
KINETICS OF AN ASPHALT SENSITIVE
TO MOLECULAR STRUCTURING
106 -
60°C
POV
Aging
105
"_
10 4
103
I
100
0
I
200
Oxidation
Time,
Figure
2.3
Chemical
The
models
means
Model
model
and
has
nothing
of
is
been
refined
characteristics
of
observed
behavioral
behavior
from
one
I
400
hr
4
Asphalt
that
more
I
300
emerging
than
a
from
during
clear
asphalt.
The
this
the
to
SHRP
is
model
as
another.
17
built
program.
understanding
characteristics
asphalt
work
of
be
able
well
as
all
Here,
it
In
the
must
is
upon
this
earlier
case
model
behavioral
to
of
explain
the
worthwhile
all
variations
to
of
the
in
review
the
manufacture
boiling
of
vacuum
stocks.
generally
very
chemistry
and
one
used
to
Some
asphalt
to
prepare
non-polar
molecules.
organized
polar
indicate
some
hand,
again
it
the
has
varies
opposite
also
0°C.
Further,
amount
asphalt
to
and
It
important
is
the
SHRP
program
to
molecules
the
here
asphalts
to
to
varies
the
viscous.
As
low
from
point
must
that
the
polar
measurable.
methods
ability
but
raised,
reduced,
below
increases
both
among
of
an
asphalt
another.
variations
can
again
the
becomes
present
And
which
on
non-polar
of
the
but
to
is
which
that
18
material
sites
data
is
temperature
to
non-
structure,
temperature
the
to
phase,
oxidation
out
the
asphalt
to
asphalt
elucidate
one
temperatures
to
and
molecules,
temperature,
one
be
of
non-polar
indicate
contributes
polar
strongly
40
the
oil
of
thermodynamic
organized
and
The
crude
model,
associate
from
The
the
of
about
decreases
number
further
varies
it
than
asphalt.
of
or
and
but
significantly
phase
As
susceptible
and
is
less
to
another.
very
is
again
of
asphalt
at
more
as
collection
data
dissociate
but
This
but
again
observations
polarity
organize,
not
Recent
asphalt
of
to
up
nature
continuous
association.
therefore
organizes,
a
methods
quite
the
resonance
and
polar
vary
tend
the
are
little
one
of
molecules.
characteristics
of
from
occurs.
phase
molecules
magnetic
ends
high
numerous
alternate
oil
is
a
from
description,
Asphalt
polar
ability
by
crude
typically
prepared
reflects
throughout
very
the
the
consistent
follows.
assemblies
is
produced
each
associations
show
dissociated
the
the
the
associations
more
as
Nuclear
Some
other
most
The
smaller
another.
The
is
therefore,
and
structures
that
have
another
is
materials.
of
properties,
it.
asphalt
which
are
portions
physical
asphalt
residuum
asphalts
similar
petroleum
form
Petroleum
distillation
petroleum
from
asphalt.
in
the
distinguish
behavioral
objective
among
asphalts
and
practice.
has
not
eventually
While
been
variations
the
completed,
in
chemical
reduce
quantitation
it
is
properties
these
of
methods
all
interesting
may
performance.
19
to
important
to
be
highway
aspects
speculate
reflected
laboratory
in
on
the
of
the
how
the
pavement
model
3.0
3.1
SPECULATION
General
ON
it
nevertheless
is
it
understood
that
unusual
to
all
pavements
will
failure
or
methodology
by
any
cost
environment,
soil
determination
of
The
related
too
PAVEMENT
subject
variations
significant
to
Permanent
2.
Rutting
3.
Fatigue
4.
Low
5.
Moisture
6.
Total
a
PERFORMANCE
is
the
are
life
modes
in
cracking
damage
of
to
adhesion
2O
a
few
years,
whereas
so
will
it
and
construction
asphalt
to
service
subject
costs.
be
time
life
of
of
which
to
Neither
is
assumed
that
The
the
The
this
be
may
work.
are
20
focus
materials.
that
is
factors.
i0
adequate.
pavement
to
particular
the
cycle
agreed
any
other
not
consistent
cracking
loss
is
are
sufficient
numerous
unacceptable,
of
of
they
harshness
are
quality
as
failure,
generally
density,
months
deformation
temperature
and
work,
is
Sufficient
few
both
generally
use
of
unless
defined
the
terms
it
fail
traffic
life
this
failure
materials
I.
of
since
materials.
service
of
in
be
justify
acceptable
methodology
here
in
eventually
must
of
frequently,
the
so
conditions,
acceptable
more
construction
do
construction,
(support)
gives
methodology
set
lifetimes
all
service
to
given
of
service
experienced
upon
TO
performance
Performance
reconstruction
and
determined
be
CHEMISTRY
describe
instructive
periodically.
to
to
is
rebuilt
of
OF
Co_tnents
While
However,
RELATIONSHIP
be
years
will
Some
speculations
chemical
on
the
properties
section
on
of
relationships
asphalts
are
of
these
given
in
failure
the
modes
sections
to
the
following
the
is actually
a
aging.
3.2 Aging
Aging
is
conditioning
step
detrimental
already
a
view
of
be
soft
and
included
which
too
and
thermal
also
and
terms
therefore
subject
stress.
Figure
the
be
beneficial
above
the
into
therefore
includes
the
On
hardens
in
in
hardening
pavement.
mixture
soft
may
excessive
performance
brittle
under
when
adequate
when
may
often
effects
or
list,
or
adequate
to
and
cracking,
aging
properties
deform,
or
either
these
temperature,
It may
is observed
may
pavement.
5 illustrates
of
detrimental.
hand,
of mechanical
rut
aging
stiffening
other
an
but
may
is
I
Well
Balanced
I
SOFT
be
points
and
too
Moisture,
Cooling
Heating
Figure
21
5
and
load
schematically
oxidation.
Highly
Associated
Fatigue and Low
Temperature
Cracking
Time, Aging,
a pavement
stiff
traffic
BRITTLE
Permanent
Deformation,
Rutting
an
beneficial
that
PERFORMANCE
Little
Association
in
A simplified
under
time,
be
be
or
Oxidation,
asphalt
or
while
the
organization
whether
any
are
in
given
bulk
set
any
heating
a
cement
the
hardening,
is
the
driving
and
the
removed
and
together
this
orientation
is
thermodynamic
a
target!
"best
to
is
so
an
roadway,
of
packing"
aging
in
the
no
in
of
constant
changes
changes.
During
a
road
and
mix-plant
hardening.
from
are
each
molecular
pavement.
also,
about
this
have
and
rigid)
are
small
eventually
state
a
better
a
distinct
to
because
temperature.
stable
ability
slow
molecule)
become
doubt,
(more
very
service
shuffle
their
thermodynamic
in
oxidation
Further,
cause
material
equilibrium
composition
polarity
temperature
22
at
the
find
or
packed
and
effect
orientation.
until
achieved.
achievement
asphalt.
in
value
hardening
thermodynamic
stiffer
is
of
themselves
differ
increasingly
are
at
stiffer
organizational
a pavement
will
as
recycling
the
stays
process.
(dipole
Aggregates,
also
by
oxidizes,
original
resulting
oxidative
viscous
as
its
in
molecular
asphalt
organizational
recycled
orienting
system.
but
the
and
cold
such
only
suffers
molecules
known
to
hardening
removes
quite
the
in
of
orientation
equilibrium
There
oxidation
medium
slowly
bound
In
for
it
periodically
during
lead
forces
that
pavement
that
soften
a
from
cement
becomes
warming
hardening
and
asphalt
temperature
process
orientation,
result
note
an
cement
effects
reversed
not
equilibrium,
The
be
since
whole
best
the
to
as
However,
will
permanent
temperature
is,
the
elevated
reverse
but
Nonetheless,
the
an
recycling
events
That
effects
to
imparts
reduced
a mixture,
other
can
However,
The
in
important
organization
portion
from
conditions.
will
is
hardening
reversible.
of
of
It
hardening,
or
absence
temperature
oxidative
which
changes,
changes
is
a moving
result
hence,
constantly
from
the
in
on
pavement
and
thermodynamic
traffic
tends
to
traffic
loads
and
equilibrium.
providing
is
slowed
is
aging
oxidation
such
products
substantial
Figure
has
in
so
result
oxidation.
varies
Compositional
variations
increase
is
temperatures.
it
is
the
While
a measurable
the
as
was
in
to move
or
up
if
orientation
orientation
own
noted
of
of
an
the
asphalt.
3.3
on
the
Relationship
of
their
Figure
own
do
in
own
as
a
4, this
oxidation.
the
oxidation
therefore
of
of
shown
in viscosity
in
While
asphalts
As
quench
increase
quenching
it.
their
other
oxidation.
dictate
to
accommodate
viscosity,
earlier
of
property
and
and
temperature
chemistry
feature
eventually
asphalts
characteristics
Speculation
heavy
thermodynamic
speed
saving
upon
their
a result
properties,
under
loads
oxidize
asphalts
maximum
chemical
viscoelastic
as
among
observed
may
changes
quench
the
and
viscosity
all
Also,
with
G,
major
doing
molecules
of
Also,
"stirred."
asphalt
in
especially
traffic
interesting
virtually
and
that
one
increases
oxidation
phenomenon
system
without
4 earlier,
of
as
for
temperature.
achievement
whether
energy
with
species,
effects
clear
the
varies
molecular
further
not
by keeping
asphalts,
show
this
additional
Oxidative
some
disorient
It
by
equilibrium
amount
at
is
of
different
not
fully
asphalt
and
does
relates
to
the
to
Various
Composition
viscosity
understood,
relate
to
performance
Failure
Modes
The
the
from
measurable
mechanical
the
or
model,
agglomerates
it
chemical
properties
structural
strength
of
that
asphalt
is
believed
(structured
units)
that
23
that
are
believed
a pavement
consist
are
is a
set
of
polars
of
to
relate
several.
to
Again
"hardcore"
dispersed
in
a
less
polar
elastic
to
behavior
molecules,
flow
to
or
each
other
under
the
expect
it
to
be
G
organize
to
be
and
very
fact,
with
is
harden
at
SEC
modulus
at
to
and
plot
material
high
molecular
high
temperature.
G.
This
susceptibility
is
observed
in
oxidation
what
should
Asphalt
feature
should
M,
and
M
size
impart
this
G
in
G
observed.
also
a
likewise
24
the
a more
is
very
a
to
have
not
low
to
that
a
have
M,
will
of
the
elasticity.
tend
be
to
expected
temperature.
Contrast
large
would
little
would
low
somewhat
observed.
One
does
G
homogeneous
relatively
it
which
Asphalt
behave
is
and
has
give
has
and
G
a material
roadways.
expected
does
of
asphalts
Asphalt
It
to
at
K
asphalt
and
it
Therefore
Asphalt
is
is
makes
material
be
respect
insensitive
temperatures.
for
than
3.
somewhat
cracking)
K.
would
Figure
is
molecular
asphalt
also
weight,
G
which
behaviors
and
is
to
character.
to
with
consider
in
temperature.
temperature
this
high
or
for
in
non-associated
observed
Again,
elastic
higher
can
contributions
much
large
low
relative
that
move
not
well
(susceptible
are
agglomerated
rut;
the
stiff
these
the
mostly
The
behavior
can
an
polar
shown
harden
of
network
the
has
composition.
Asphalt
at
by
viscous
the
which
are
as
studies.
feature
with
a
Deformation.
compatible
especially
compositional
stress.
plots
not
of
a material
formed
with
parts
vary
is
network
a material
phase,
very
result
the
Permanent
SEC
does
deform,
Asphalt
and
index
It
of
behavior
dispersing
oxidation.
or
also
Their
compatibility
rut
result
various
viscous
M.
The
prolonged
Ruttinq
and
largely
is
because
3.3.1
K,
it
a
creep
and
phase.
as
but
elastic
G,
nonpolar
this
amount
greater
the
In
of
elastic
propensity
with
its
like
asphalt
material
temperature
truly
K
than
at
K
If
heretofore
properties
has
blending
of
separated
were
not
phases
observed
with
more
one
than
within
reason,
pushed
up
or
contribution
of
down
of
intensive
study
3.3.2
failure
the
is
The
very
potential
feature.
At
organize
into
to
low
variety
This
area
the
is
as
not
present
needed
fully
Cracking.
be
the
Instead,
healing
rigid
matrix
will
eventually
compounded
temperature,
a more
structured
the
a
crude
by
more
form
25
of
yet
can
the
one
is
clear
can,
can
be
under
understanding
since
many
oils.
another
an
or
whatever
asphalt
occur.
suffer
another
term
deform
and
likely
constant
and
crack.
organizational
by
If
to
The
fatigue
materials
seen
serious
composition.
fractures
be
for
varied
binder
cannot
The
relative
and
colloid,
neutral
as
be
is
to
asphalt
that
the
purposes,
ability
a point
is
of
Cracking
the
material!
Viscosities
can
related
mixed
asphalt
blending,
understood
micelle,
rigid,
was
"solvent"
cross
different
can
good
moduli)
different
resulting
properties.
to
crack
a
Obviously,
(agglomerate,
lost.
not
specification
from
again
too
is
of
original
(a measure
time.
Fatigue
and
yet
for
mixtures
and
be
is
either
cross
properties
asphalt
The
of
of
viscous
becomes
of
wide
one
appropriate
and
preferred)
working
By
elastic
sold
separated
first.
the
at
will
asphalt
in
fractions
of
from
These
changes
blending
viscosity
results
asphalts.
asphalt.
deltas
network
be
second
second
Tan
molecular
will
the
roadways,
elastically
a
of
phase
performance
recent
Major
by
will.
Thermal
in
of
a
SEC.
dispersed
the
at
phenomenon
are
the
the
by
to
some
phases
prepared
times
achieve
significantly.
asphalts
asphalt
of
phase
dispersing
phase
i000
composition
consider
generated
case,
phase
dispersed
this
an
of
obvious,
and
dispersing
dispersing
of
been
were
in
In
the
relationship
dispersed
asphalts.
was
the
begin
to
differential
scanning
calorimetry
subject
to
cracking
shrink
significantly
of
polarity
low
Again,
it
other
with
to
equal,
ratio
Aliphatic/aromatic
ratios
the
to
very
rapid
measurements.
go
Adhesion
together
only
serious
moisture
occur.
At
involve
both
to
either
to
of
adhesion,
composition
studies.
considering
governed
as
Specific
functional
Certainly
overall
organic
much
molecules,
per
se,
is
the
components
at
the
promotes
of
has
SHRP
and
the
it
is
probably
predict
it
moisture
is
damage
a
may
definition,
it
commissioned
interesting
from
damage
certainly
scope
of
equal.
aggregates,
within
and
feature
moisture
While
asphalt
molecular
polarity,
or
and
By
some
occurs,
also
must
studies
the
of
the
binder
observations
can
be
binder.
in
groups
but
the
Hence,
are
NMR,
adhesion.
not
show
shrinkage
adhesion
forms
asphalts
Nevertheless,
only
of
of
All
temperature.
Adhesion
other
interaction
another.
materials
directly
of
organization
compositional
by
cements
cracking.
characteristics
loss
aggregate.
the
to
if
the
Damaqe.
only
of
and
some
aggravates
expected
shrinkage
consider
result
decreasing
to
brittle
worse,
asphalt
determined
While
quite
aliphatic
other
problem,
and
the
examination
Adhesion
point.
point,
asphalt
all
Moisture
damage
this
investigate
made
a
one
related
be
a
This
be
measure
and
as
with
would
is
matters
linear
shrink
can
practical
3.3.3
more
when
more
make
from
closely
aliphatic/aromatic
DSC
To
components.
to
most
asphalt
temperature
temperature
be
the
composition
tendency
low
expected
low
nonpolar
being
at
Now,
stress.
at
and
pronounced
cracking
is
under
varies
things
most
(DSC).
level
(molecular
that
to
aggregate
as
at
types)
is,
attraction
26
the
polar
to
be
inter-molecular
seem
separation
of
appears
to
of
be
charge
asphalt
very
level.
important.
within
components
the
to
the
also
polar
Strategic
surface
Highway
some
and
Some
show
For
polar
with
in
asphalt
may
not
asphalt
is
capability
of
moisture
with
result
of
effects
a
acids
of
removed
salts
of
practical
in
pyridines
that
organic
molecules
elsewhere
salts,
from
aggregate
there
not
sodium
is
in
within
it
in
salts
a
the
more
would
are
been
sodium
easily.
of
of
The
tenacity
evaluation
program.
27
the
the
the
user
of
this
are
to
the
a
the
be
type
of
or
The
it
among
spectrum
acids
of
assure
and
of
other
action
salts.
adhesion
as
basic
tend
to
extremes
of
behavior,
potassium,
to
the
surfaces
with
monovalent
somewhat
that
Calcium
resistant
in
mixtures.
aggregate
or
this
as
polar,
polars
alone
composition
observed
varies
highly
the
other
aggregate
quite
a
the
on
measurable
to
etc.
pavement
has
all
in
asphalt
behoove
form
spectrum
asphalt.
as
in
More
like
and
polarity
adhesion
is
this
quite
the
But
Asphalt
adhere
but
such
much
of
water.
while
negative,
interaction
changes
has
with
simply
good
the
quite
be
aggregate.
water,
the
temperature,
to
the
water
to
salts,
cation
are
and
tend
easily,
are
an
of
it
acid
acids
of
of
asphalt
some
content,
transporting
into
more
sites,
including
(pyridines)
varies
environment.
water
viewpoint,
asphalts
obvious
done
in
behavior
achieve
Incorporation
aggregate
Monovalent
divalent
its
composition
Carboxylic
be
to
Absorption
level
to
of
section.
compounds
salt.
surface
of
vary
considered
because
and
molecular
from
be
within
aggregates
moisture
will
incorporating
invasion
removed
with
by
workers
positive
sufficient
oxidation.
tenaciously.
have
affected
the
nitrogen
From
be
that
aggregate
arises
polar
asphalt
of
the
tend
the
damage
varies
cases
polarity
Adhesion
Several
shown
aggregate
asphalt
because
some
in
discussion,
surface.
have
aggregates
in
At
in
variation
this
aggregate.
Program
substantially,
environment.
of
water.
the
examples
should
the
is
being
be
Moisture
problem
damage
in
reducing
pavement.
the
this
water
will
in
also
come
in
performance
into
asphalt
the
chemical
by
soaks
into
polar
components.
viewpoint,
Upon
with
reduced
strength
and
Aged
oxidized
asphalts,
or
(oxidation
new
asphalts.
This
of
pavement
counterpart
age.
new
counter
measured
in
behavior
would
But
pavements,
to
terms
varies
of
each
the
with
of
to
be
polar
have
mechanical
a
chemical
are
also
28
some
affect
its
water
like
is transported
molecules
asphalt,
it.
like
From
the
typically
other
of
to
water
will
a
dilution
of
results
in
deformation.
polars
a greater
extent
than
considerations.
viewpoint,
harder
effects
of
most
Still,
water
of moisture
combined
remove
extent
amounts
to
is
Water,
polarity
properties
composition.
or
water
effects
The
This
rutting
from
will
somewhat
greater
from
to
softening
is
in
pavements
other.
the
solvent.
expected
so the
some
into
incorporate
invasion,
aged
of
water
results
which
tend
to
typically
weight
further
moisture
somewhat
the
molecular
products),
probability
with
a low
action
asphalt
and
invasion
properties,
the
concrete.
in
unavoidable.
to pavement.
the
attraction
are
common
factor
water
adequate
and
another
a major
clear,
pavement
material
of
is
in
water
virtue
mechanical
invasion
in
be
is
is
of moisture
design
asphalt
a highly
asphalt
effect
the
to
effects
with
adhesion
design
but
that
its
of
highway
so the
resist
loss
water,
consider
contact
is
the
polar
to
when
aggregate,
of
roadways,
discussion,
and
apparent
Certainly,
availability
omnipresent
For
without
the
than
The
increases
their
and
oxidation
are
better
mix.
As
usual,
are
4.0
The
chemistry
of
intermolecular
levels
thousands
of
polarity
among
properties
has
molecular
on
mechanical
tend
or
by
involvement
exact
nature
of
of
the
distribution
of
charge
structuring
leads
little
structuring
Oxidation
adds
contributing
to
Finally,
word
As
differently
asphalts.
new
the
The
crude
as
consistent
used
and
to
are
airplane
other,
be
among
and
are
performance,
and
in
rubber
are
achieve
29
of
to
the
the
may
species.
The
the
Excessive
crack,
while
under
stress.
asphalt
the
same
cement
tremendous
them.
is
than
differences
asphalts
general,
too
cement
by
binder.
used
there
manufacture
describe
of
significant
glue
so
deform
within
should
chemical
to
brittleness
zones
there
to
which
chemical
interactions
molecule.
tend
nonpolars
of
In
important
which
materials
asphalt
differences
oils
specific
cements
to
different
the
and
related
These
The
nonpolars
effects
are
of
asphalt.
offered.
less
hundreds
physical
polar
the
polars.
is
the
and
less
asphalt
specie
hardening
word
each
specifications
therefore
brittle
glue,
from
numerous
structures
much
carpenters
of
within
age
the
the
glue.
e.g.,
to
of
that
particular
and
been
and
clear
polars
on
have
the
any
leads
of
speculations
chemical
to
any
while
among
is
widely
balance
properties
molecular
It
varies
performance
structural
the
within
associate
structuring
arise
exist
the
to
at
discussed.
Several
pavement
intermolecular
of
by
dissociation.
composition
been
molecules
governed
Polars
asphalt
species
asphalt
are
components.
cause
petroleum
SU_a4ARY
as
The
as
among
glues,
perform
differences
great
as
objective
consistent
high
sense
priority
the
of
behavior,
from
the
the
very
among
diversity
developing
and
user's
cost
standpoint.
supply
line
there
That
is
But
(crude
little
is,
the
selection
asphalts
achievement
of
value
of
the
properties.
obtain
of
a very
limited
are
needed
that
is
with
that
is
are
to
to
information
binders
variety
set
It
performance
studies
3O
of
perform
cost-effective
materials,
the
source
crude
oils
produced
today.
to
in
a
with
select
supply.
that
will
A
understanding
material
used
of
obvious
frequently
an
and
to
asphalts
develop
be
the
of
therefore
produce
can
will
that
limiting
impossible.
materials
realize
a wide
of
composition
this
also
significantly
of
features
must
of
consistent
Then
to
user
consists
is
modification
compositional
asphalts
oil)
chance
manufacture
require
the
principal
of
what
the
desired
and/or
modify
cost-effective
manner.
Asphalt
Advisory
Committee
George West
Shell Oil Company
Thomas D. Moreland, chairman
Moreland Altobelli Associates, lnc.
Liaisons
Gale C. Page, vice chairman
Florida Department of Transportation
Avery D. Adcock
United States Air Force
Peter A. Bellin
Niedersachsisches
Ted Ferragut
Federal Highway Administration
Landesamt
fiir Strass7enbau
Donald G. Fohs
Dale Decker
Federal Highway Administration
National Asphalt Paving Association
Fredrick D. Hejl
Joseph L. Goodrich
Chevron Research Company
Transportation
Research
Board
Aston McLaughlin
Eric Harm
Federal Aviation
Illinois Department
of Transportation
Bill Weseman
Charles Hughes
Virginia Highway
Administration
Federal Highway
& Transportation
Research
Administration
Council
Expert Task Group
Robert G. Jenkins
University of Cincinnati
Anthony J. Kriech
Heritage Group Company
Wayne Brule
New York State Department
Richard Langlois
Universite Larval
Richard C. Meininger
National Aggregates Association
Nicholas Nahas
EXXON Chemical
Ernest Bastian, Jr.
Federal Highway Administration
of Transportation
Joseph L. Goodrich
Chevron Research Company
Woody Halstead
Consultant
Co.
Gayle King
Bituminous Materials
Charles F. Ports
APAC, lnc.
Co., lnc.
Robert F. LaForce
Ron Reese
California Department
Colorado Department
of Transportation
of Transportation
Mark Plummer
Donald E. Shaw
Georgia-Pacific
Corporation
Marathon Oil Company
Raymond Pavlovich
Exxon Chemical Company
Scott Shuler
The Asphalt Institute
Ron Reese
Harold E. Smith
City of Des Moines
California Department
Thomas J. Snyder
Marathon Oil Company
Colorado
of Transportation
Scott Shuler
Richard H. Sullivan
Minnesota
Department
A. Haleem
Tahir
of Transportation
American Association of State Highway and
Transportation Officials
Jack Telford
Oklahoma Department
of Transportation
Paving Association