Page 1 of 6
European Journal of Business &
Social Sciences
Available at https://ejbss.org/
ISSN: 2235-767X
Volume 07 Issue 05
May 2019
Available online:https://ejbss.org/ P a g e | 917
Pavement Material Characterization and Its Influence On The Stress Strainanalysis Of
Pavement Layers
L. MUTHUAZHAKAN
DEPARTMENT OF CIVIL ENGINEERING
PRIST (Deemed to be University), THANJAVUR.
ABSTRACT
Design of flexible pavement is largely based on empirical methods using layered elastic and
twodimensional finite element (FE) analysis. Currently a shift underway towards more
mechanistic design techniques to minimize the limitations in determining stress, strain and
displacement in pavement analysis.
INTRODUCTION
The interstate and highways connecting
cities and sustaining economic exchange
are integral to the infrastructure of a
country. Transportation is considered to be
one of the most important infrastructure
components influencing production and
economic activities. Presently there are
67% of roadways with respect to the total
land area of Bangladesh; more than 98%
are topped by asphalt. Though scarcity of
lands, demand of road pavement is
increasing considerably to mitigate the
need of basic movements and enhance
economic activities.
So there exists considerable pressure for
investment in the transportation sector. But
unit length of the construction cost of
pavement is massive as per empirical
design guideline because the complex
interaction of materials of different layers
cannot be assessed and investigated easily.
Economic and the efficient pavement
system can be designed through
mechanistic behavioral analysis using the
application of finite element. This research
is a part of a broader study (Rahman M.T.,
2009) and an attempt is made in this study
to analyze stressstrain characteristics of
asphalt pavement through proper
understanding of various traffic and
loading factors and their interaction with
the pavement distress and failure initiation.
The specific objectives of this study can be
summarized as follows:
• Develop proper element type and
effective meshing strategies for flexible
pavement in
finite element software.Analyze proper tire
imprint area for inflation pressures.
Page 2 of 6
European Journal of Business &
Social Sciences
Available at https://ejbss.org/
ISSN: 2235-767X
Volume 07 Issue 05
May 2019
Available online:https://ejbss.org/ P a g e | 918
•
Estimate the appropriate tire inflation press
ure.
BITUMINOUS MIXTURES (VIRGIN
AND RECYCLED)
The properties of bituminous materials
used in pavements are discussed in this
section. These include the bituminous
materials themselves, the mixtures made
with the bituminous materials, and the
properties of the bituminous mixtures as
used in different layers within the
pavement system.
1. Bituminous Materials. Bituminous
materials consist of a variety of products in
different types and grades. Bituminous
materials are discussed in Mn/DOT's
Specification 3151. Two broad types of
bitumens are used in pavements - asphalt
cement, conforming to AASHTO M 20
and emulsified (or modified) asphalts
(AASHTO M 140 and M 208, modified).
The asphalt binder acts as a binding agent
to glue aggregate particles into a dense
mass and to waterproof the mixture.
When bound together, the mineral
aggregate acts as a stone framework to
impart strength and toughness to the
system. The performance of the mixture is
affected both by the properties of the
individual components and their combined
reaction in the system.
In the late 1990’s, Mn/DOT adopted the
Strategic Highway Research Program
(SHRP) Superpave TM system. The
Superpave TM system incorporates
performance-based asphalt material
characterizations designed to improve
pavement performance by controlling
rutting, low temperature cracking, and
fatigue cracking. Therefore, Mn/DOT
currently specifies asphalt binders using
the Performance Graded (PG) Asphalt
Binder Specification resulting from the
Superpave TM project. The PG
specification differs from the previous
specification in that the tests used to
measure physical asphalt properties can be
directly related to field performance by
engineering principles.
Performance graded (PG) binders are
defined by a term such as PG 64-22. The
first number (in this case 64) is the “high
temperature grade.” This means that the
binder possesses adequate physical
Page 3 of 6
European Journal of Business &
Social Sciences
Available at https://ejbss.org/
ISSN: 2235-767X
Volume 07 Issue 05
May 2019
Available online:https://ejbss.org/ P a g e | 919
properties up to at least 64°C. This is
intended to correspond with the high
temperature in the climate in which the
binder is expected to serve. Likewise, the
second number (-22) is the “low
temperature grade”, which indicates that
the binder possesses adequate physical
properties down to at least -22°C. Three
asphalt binder characteristics are important
in asphalt mixture performance:
temperature susceptibility, visoelasticity,
and aging.
a. Asphalt’s properties are temperature
susceptible: asphalt is stiffer at colder
temperatures. That is why a specified test
temperature must accompany almost every
asphalt cement and mixture test. Without
specifying a test temperature, the test
result cannot be effectively interpreted.
Similarly, asphalt cement behavior is also
dependent on the duration of loading:
asphalt is stiffer under a shorter load
duration. The dependence of asphalt
cement behavior on temperature and load
duration means that these two factors can
be used interchangeably. That is, a slow
loading rate can be simulated by high
temperatures and fast loading rate can be
simulated by low temperatures.
b. Asphalt cement is a viscoelastic material
because it simultaneously displays both
viscous and elastic characteristics. At high
temperatures (e.g. > 100°C), asphalt
cement acts almost entirely as a viscous
fluid, displaying the consistency of a
lubricant such as motor oil. At very low
temperatures (e.g., < 0°C), asphalt cement
behaves mostly like an elastic solid,
rebounding to its original shape when
loaded and unloaded. At the intermediate
temperatures found in most pavement
systems, asphalt cement has characteristics
of both a viscous fluid and an elastic solid.
Because asphalt is organic, it reacts with
oxygen from the environment. Oxidation
changes the structure and composition of
the asphalt molecules. Oxidation causes
the asphalt to become more brittle, leading
to the term oxidative, or age, hardening.
Oxidation occurs more rapidly at higher
temperatures. A considerable amount of
hardening occurs during HMA production,
when the asphalt is heated to facilitate
mixing and compaction. That is also why
oxidation is more of a concern when the
asphalt cement is used in a hot, desert
climate.
2. Bituminous Mixtures. The bituminous
mixtures used for pavement construction
