Evaluation of Road and Pavement Construction Materials in Civil Engineering

EVALUATION OF ROAD AND PAVEMENT CONSTRUCTION MATERIALS IN CIVIL
ENGINEERING
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Evaluation of Road and Pavement Construction Materials in Civil Engineering 2
Abstract
Any construction work in civil engineering requires an understanding of fundamentals of design,
and economic aspects. Most importantly however, a civil engineer ought to have in-depth
understanding of the properties of the construction material. The asphalt concrete mechanistic-
empirical train model is used in this paper to evaluate two tests types: the full scale accelerated
and the extra-large wheel tracking (ELWT) test with use of a Heavy Vehicle Simulator (HVS).
The ELWT was carried out on three different asphalt mixtures. The ELWT test took place at
different temperatures and different tyre inflation pressures. The test occurring at such varied
conditions aids in justifying the accuracy of the test by making the conditions in the laboratory as
close to environmental conditions as possible. Permanent deformations measured on the asphalts
slabs were further modelled by use of the United States Mechanistic Empirical Pavement Design
Guide (US MEPDG) strain model. The calibration factors obtained were in the + or – 20% range
from unity. From these results, it could be that the differences in the scale, geometry and
configuration between the two tests devices were the reason behind the calibration factors as
observed from the results.
Key words: Pavement, Asbestos, Asphalt Pavement Analyzer (APA), deformation
Research Plan
The Description of ELWT and the Test program
The test was done on slabs fifty centimeters in width and seventy centimeters in length,
the slab should a thickness of twelve centimeters. A small inflated radial tyre (tyre pressure
between 500 to 1000kPa) is then used to apply load of up to 25kN on the test slabs (Choi and
Kim, 2015). The wheel travels longitudinally with a speed of between 1 to 5 km/h. Air and
pavements temperatures were measured continuously while being varied between (5-60) ºC. The

Evaluation of Road and Pavement Construction Materials in Civil Engineering 3
high-precision laser beam equipment was used to derive the rutting and or deformation in the test
slab (Zhou, 2011)
.
The standard asphalt mixtures used were three: (AG22) for the base layer bituminous,
(ABb22) the binder layer and (ABT11) for surfacing. The ELWT device was used to test these
mixtures. The total prepared asphalt slabs were nine with three replicas for each mix. The
European standard practices were used to prepare the mixes which were later roller compacted so
as to attain the desired quality.
The tyre pressure and the ELWT tests were adjusted in order to account for the different
places and or location in the actual construction and or real world conditions. A 10kN load was
chosen for the experiment. Temperatures of (10, 20 and 30) º C for the pavement were used for
each mix of the first two asphalt slabs. For the 10 º C and 20 º C test load cycles of 14000 were
applied. Load cycles of 25, 000 were used for the 30 °C pavement temperature. The third group
of the slab mixture was used at temperatures of ten, fifteen, twenty-five and thirty five degree
Celsius with load cycles of 14, 000 being used for the entirety of these temperatures. To guard
the slabs against damage for the subsequent tests, increasing temperatures were used (Biligiri,
2013). The velocity of the wheel was maintained at 2.5km/h for the tests run.
HVS test program
The results from this test were used for verification purposes. The HVS method allows
for a single and or a twin wheel load with magnitudes ranging from 30kN to 110kN moving
at12km/h. Add on facilities were used to alter and control environmental influences for example
temperature. The HVS test used was an asphalt surface course with a five-layer system (ABT11),