Evaluation of Road and Pavement Construction Materials in Civil Engineering

This paper evaluates two types of tests for road and pavement construction materials in civil engineering using the asphalt concrete mechanistic-empirical train model. The results show 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.

EVALUATION OF ROAD AND PAVEMENT CONSTRUCTION MATERIALS IN CIVIL
ENGINEERING
Module Name
Assessment Title
Student Number
Date

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 ℃ 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),

Evaluation of Road and Pavement Construction Materials in Civil Engineering 4
binder layer (ABb22) and (AG22) bituminous base. Fitted in the test structure to measure the
deformations were pressure cells and strain gauges.
HVS Test Structure material Properties
The assumptions made include a 0.35 Poisson’s ratio for all materials employed (Saride,
Avirneni and Challapalli, 2016). For purposes of converting the speed into frequency, the depth,
speed and loading frequency relation in equation 1 below was used.
log t=0.5 z−0.2−0.94 logV (1)
fo= 1
2 π t , aT=fo /fT (2)
T (in seconds) loading time, z depth (meters), V (km/h) velocity, fo frequency for loading
at To (the temperature of reference), fT frequency at temperature T.
To model the permanent deformations in layers of asphalt, a layer strain approach was
utilized following the equation 3 below:
(3)
εp,i and ∆ zi represent the permanent perpendicularly strain and ith sublayer the thickness,
respectively, n represents number in total of sublayers, Rd indicates the rut depth.
Literature review
Asphalt Pavement Analyzer APA, is an example of wheel tracking devices that can be in
the evaluation of the rutting action of mixtures of asphalt under loading and environmental
conditions simulating the actual parameters (Fakhri and Amoosoltani, 2017). He and Wong,
(2007) conducted studies on wheel tracking devices that showed these devices have a great
impact on measurement of rut. Papavasiliou and Loizos, (2013) demonstrated that the rutting rate

Evaluation of Road and Pavement Construction Materials in Civil Engineering 5
is faster for small wheel-tracking machines as compared to larger devices. It means therefore that
larger devices do not offer convenience in the evaluation of permanent deformation model
features with a high correlation to the actual conditions in the field as the test specimen’s width
is smaller. Li and Li, (2012) successfully utilized ELWT used in this model in the evaluation of
permanent deformation in bituminous mixtures.
Even though APT test utilizing HVS are expensive to carry out, they are a close
representation of real field conditions (Gao et al., 2018). Project research presented in this paper
has demonstrated the utilization of ELWT and APT in estimation of permanent deformation
features for asphalt layers. Multiple samples can be tested using this method at varying load rates
and speeds. The samples are prepared, loaded and positioned easily. The chamber temperature is
also efficiently regulated with heating strips and cooling agents fitted with a controller that has a
microprocessor. There is accurate evaluation of rutting being provided by the versatile wheel
tester. The advanced drive system allowing for testing of speeds and load rates simultaneously
and a one of a kind high pressure system makes APA a suitable test for the study of rutting,
moisture susceptibility of cold and hot mixes of asphalt and definitely fatigue cracking.

Evaluation of Road and Pavement Construction Materials in Civil Engineering 6
References
Biligiri, K. (2013). Effect of pavement materials’ damping properties on tyre/road noise
characteristics. Construction and Building Materials, 49, pp.223-232.
Choi, S. and Kim, Y. (2015). Applied Mechanics and Materials III. Zurich: Trans Tech
Publications.
Fakhri, M. and Amoosoltani, E. (2017). The effect of Reclaimed Asphalt Pavement and crumb
rubber on mechanical properties of Roller Compacted Concrete Pavement. Construction and
Building Materials, 137, pp.470-484.
Gao, L., Li, H., Xie, J., Yu, Z. and Charmot, S. (2018). Evaluation of pavement performance for
reclaimed asphalt materials in different layers. Construction and Building Materials, 159,
pp.561-566.
He, G. and Wong, W. (2007). Laboratory study on permanent deformation of foamed asphalt
mix incorporating reclaimed asphalt pavement materials. Construction and Building Materials,
21(8), pp.1809-1819.
Li, C. and Li, L. (2012). Criteria for controlling rutting of asphalt concrete materials in sloped
pavement. Construction and Building Materials, 35, pp.330-339.
Papavasiliou, V. and Loizos, A. (2013). Field performance and fatigue characteristics of recycled
pavement materials treated with foamed asphalt. Construction and Building Materials, 48,
pp.677-684.
Saride, S., Avirneni, D. and Challapalli, S. (2016). Micro-mechanical interaction of activated fly
ash mortar and reclaimed asphalt pavement materials. Construction and Building Materials, 123,
pp.424-435.
Zhou, X. (2011). Architecture and building materials. Durnten-Zurich: TTP, Trans Tech
Publications.