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Performance Evaluation of Using Waste Toner in Bituminous Material by Focusing on Aging and Moisture Susceptibility

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  • Amirkabir University of Technology (Polytechnic)

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This study investigated the effect of waste toner as a cost-effective enhancement modifier on short-term aging and moisture resistance of asphalt binders and mixtures. Moreover, the mechanism of asphalt binder aging and moisture resistance was reviewed, aiming to provide promising evaluation methods for assessing short-term aging resistance of asphalt binders as well as moisture resistance of asphalt binders and mixtures. First, the aging resistance of neat and toner-modified asphalt (TMA) binders was evaluated using three approaches: rheological aging index (RAI), viscosity aging index (VAI), and chemical functional group indices based on data obtained from Fourier transform infrared spectroscopy (FTIR) analysis. To measure viscoelastic and viscosity characteristics of neat and TMA binders, a dynamic shear rheometer (DSR) and a viscometer were employed, respectively. Second, the moisture resistance of asphalt binders and mixtures were investigated based on analyzing the infrared spectrum and tensile strength ratio (TSR), respectively. The findings indicated that modifying binder with low percentages of waste toner enhanced the short-term aging resistance. Also, TMA binders containing 12% of waste toner presented a significant improvement in moisture resistance of asphalt binders and mixtures.
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Performance Evaluation of Using Waste Toner in
Bituminous Material by Focusing on Aging
and Moisture Susceptibility
Mohammad Ali Notani1; Pouria Hajikarimi, Ph.D.2; Fereidoon Moghadas Nejad, Ph.D.3;
and Ali Khodaii, Ph.D.4
Abstract: This study investigated the effect of waste toner as a cost-effective enhancement modifier on short-term aging and moisture
resistance of asphalt binders and mixtures. Moreover, the mechanism of asphalt binder aging and moisture resistance was reviewed, aiming
to provide promising evaluation methods for assessing short-term aging resistance of asphalt binders as well as moisture resistance of asphalt
binders and mixtures. First, the aging resistance of neat and toner-modified asphalt (TMA) binders was evaluated using three approaches:
rheological aging index (RAI), viscosity aging index (VAI), and chemical functional group indices based on data obtained from Fourier
transform infrared spectroscopy (FTIR) analysis. To measure viscoelastic and viscosity characteristics of neat and TMA binders, a dynamic
shear rheometer (DSR) and a viscometer were employed, respectively. Second, the moisture resistance of asphalt binders and mixtures were
investigated based on analyzing the infrared spectrum and tensile strength ratio (TSR), respectively. The findings indicated that modifying
binder with low percentages of waste toner enhanced the short-term aging resistance. Also, TMA binders containing 12% of waste toner
presented a significant improvement in moisture resistance of asphalt binders and mixtures. DOI: 10.1061/(ASCE)MT.1943-5533.0003451.
© 2020 American Society of Civil Engineers.
Author keywords: Fourier transform infrared spectroscopy (FTIR); Moisture susceptibility; Waste toner; Asphalt mixture; Aging
resistance.
Introduction
Toner is a raw material commonly used for printers and copiers.
Because all of the produced toners cannot be fully utilized, there
is a waste amount of toner from either printing or the toner produc-
tion process (Yildirim and Kennedy 2003;Notani and Mokhtarnejad
2018). In the production process, some of the produced toners can-
not proceed to the next step because they do not meet quality re-
quirements; therefore, they become waste (Yildirim and Kennedy
2003). Moreover, in the printing process, a considerable amount of
leftover burned toner is produced, which is rendered useless (Notani
and Mokhtarnejad 2018;Notani et al. 2020b). The waste toner must
be landfilled since there can be no better utilization and recycling
technique, especially for burned toner.
Previous studies have reported that the leftover burned toner that
remains within the cartridge shows a uniform size distribution
(Notani et al. 2019). Sun and Beach [Chemically prepared toner
and process therefor,US Patent No. 6,991,884 (2006)] reported that
there are several main copolymers used in the toner production pro-
cess, such as styrene acrylate, styrene-butadiene copolymer, and
polyester resin. Notani et al. (2019) performed an X-ray diffraction
(XRD) test on waste toner powder and proved that landfilling
of this waste material causes serious environmental problems due
to the presence of numerous heavy and semiheavy constituents such
as ferric oxide (Fe2O3) and lanthanum (La), which cause aquatic
toxicity. Moreover, it is indicated that the ferric oxide has a high
density, which turns the toner-modified binder into multiphases if a
high percentage is used. In the same vein, waste toner includes ti-
tanium dioxide (TiO2), which is commonly used in color pigment.
The presence of titanium dioxide contributes to the resistance of as-
phalt binders against the negative effect of high service temperature
(Qian et al. 2019). The waste toner can be an appropriate carbon-
based modifier of asphalt binders as it contains polyester resins
and styrene acrylate, which may cause chemical interactions between
toner ingredients and asphalt binder components. However, few stud-
ies have been devoted to adding waste toner to a neat asphalt binder
as an additive for enhancing rheological and mechanical character-
istics of asphalt binder as a reuse scenario (Solaimanian et al. 1998).
It has been conclusively shown that adding waste toner to as-
phalt binders results in higher stiffness that shows a higher fluid
resistance (Yildirim et al. 2004). It was also shown that modifying
asphalt binders with waste toner enhances high-temperature char-
acteristics of asphalt mixtures as far as permanent deformation re-
sistance is concerned. Notani and Mokhtarnejad (2018) represented
that waste toner improves the viscoelastic properties of asphalt
binders and provokes its self-healing capability. Furthermore, it
has been reported that the toner-modified asphalt (TMA) binder
indicates better fatigue resistance in terms of the number of loading
cycles and crack propagation rate in comparison with the neat
1Ph.D. Student, Lyles School of Civil Engineering, Purdue Univ., West
Lafayette, IN 47907-2051 (corresponding author). ORCID: https://orcid
.org/0000-0002-4856-656X. Email: mnotani@purdue.edu
2Assistant Professor, Dept. of Civil and Environmental Engineering,
Amirkabir Univ. of Technology, Tehran 158754413, Iran. Email:
Phajikarimi@aut.ac.ir
3Professor, Dept. of Civil and Environmental Engineering, Amirkabir
Univ. of Technology, Tehran 158754413, Iran. ORCID: https://orcid.org
/0000-0003-3830-4555. Email: moghadas@aut.ac.ir
4Professor, Dept. of Civil and Environmental Engineering, Amirkabir
Univ. of Technology, Tehran 158754413, Iran. Email: khodaii@aut.ac.ir
Note. This manuscript was submitted on November 24, 2019; approved
on May 26, 2020; published online on October 20, 2020. Discussion period
open until March 20, 2021; separate discussions must be submitted for in-
dividual papers. This paper is part of the Journal of Materials in Civil
Engineering, © ASCE, ISSN 0899-1561.
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asphalt binder (Notani et al. 2018). Although some mechanical and
rheological investigations have been done, the aging and moisture
resistance of TMA binders and mixtures is not yet known. There-
fore, the asphalt aging phenomenon and its moisture susceptibility
are briefly introduced as follows.
Asphalt Aging Phenomenon
Asphalt binder aging is an intrinsic phenomenon which commonly
initiates from the beginning and throughout the period of hot
mix asphalt (HMA) production in asphalt batching plants and then
increases during the pavement service life (Alsalihi et al. 2017;
Rahbar-Rastegar et al. 2019;Rahmani et al. 2018). Aging has been
increasingly recognized as a destructive phenomenon which accel-
erates an asphalt mixtures deterioration rate (Haghshenas et al.
2020;Wang et al. 2019a;Zhang et al. 2019a). As shown as a sche-
matic description in Fig. 1, aging of asphalt mixtures occurs by a
two-step process: short-term aging, which occurs during HMA pro-
duction and paving, and long-term aging, which occurs during the
asphalt pavement service life. Therefore, producing an asphalt
binder with high resistance against asphalt aging phenomena would
result in a long-lasting pavement surface.
It has been claimed that transforming the naphthenic hydrocar-
bon to higher molecular weight aromatic hydrocarbon and then
becoming asphaltenes has led to increasing the binder viscosity
(Corbett and Schweyer 1981;Zhang et al. 2019b;Pouranian
et al. 2020). Roberts et al. (1991) believed that six factors contribute
to the asphalt binder aging phenomenon: oxidation, polymeriza-
tion, volatilization, thixotropy, syneresis, and separation. Consis-
tently, Petersen et al. (2000) have claimed that asphalt binder
aging occurs in three ways: oxidation, evaporation, and crystalli-
zation, which leads to a stiffer binder due to higher viscosity in
comparison with the unaged binder. Meanwhile, a search of the
literature revealed that the source of asphalt binder aging is the
reduction of low-molecular-weight aromatics and, concurrently, in-
creasing the ratio of asphaltenes to maltene (Cavalli et al. 2018;Fini
et al. 2016). Short-term aging formed the dominant focus of a study
by Lu and Isacsson (2000) in which the authors indicated that
short-term aging causes chemical changes within asphalt binder
functional groups such as carbonyl and sulfoxide. To be more
clear, Petersen (2009) has declared that the main evidence of the
short-term aging effect on asphalt binder corresponds to the pres-
ence of benzylic, sulfoxide, and free hydroxyl radicalsconstitu-
ents. In addition, it was asserted that the relative amount of
asphaltenes and the mass percentage of oxygen in both carbonyl
and sulfoxide chemical functional groups shows the extension of
asphalt binder aging (Petersen 2009).
Moisture Susceptibility
Moisture damage is the primary distress of asphalt pavement that
demolishes asphalt binder-aggregate adhesion (Azarion et al.
2019). It is one of the most challenging distress to evaluate and
recognize in asphalt pavements because pavement surfaces com-
monly have a variety of distresses such as shoving, rutting, ravel-
ing, and cracking (Arambula et al. 2010;Malakooti et al. 2018;
Yeganeh et al. 2019;Epps 2000). The adhesive strength between
the asphalt binder and aggregates plays a substantial role in the
HMA moisture susceptibility (Nakhaei et al. 2018). The principal
mechanism of moisture susceptibility is an interfacial adhesive
bond failure between asphalt binder and aggregate particles due to
loss of adhesion and strength of the bitumen film (Pérez et al. 2012;
Pouranian and Haddock 2019;Wang et al. 2019b;Zhang et al.
2017;Kim et al. 2018). The absorption and displacement of polar
elements of asphaltene on the water-coated aggregates is a major
reason for moisture damage and stripping of the asphalt pavement
surface (Grenfell et al. 2014). It has been demonstrated that the
essential chemical functionality components which possess more
tendency to be absorbed by water are sulfoxide, carboxylic acids,
hydroxyl, anhydrides, phenolics, ketones, 2-quinoline types, and
nitrogen. Among them, the carboxylic acid and the sulfoxide group
are the most influential groups of asphalt binders for displacement
reaction in the presence of water molecules (Kanitpong and Bahia
2005;Shishehbor et al. 2019).
Fig. 1. Schematic description of short-term and long-term aging of asphalt binder.
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To enhance asphalt binders intrinsic properties to achieve a
higher resistance against pavement distress, many researchers
have considered asphalt binder modification with carbon black,
crumb rubber, styrene-butadiene-styrene (SBS), and other materi-
als. (Vila-Cortavitarte et al. 2018;Pouranian and Shishehbor 2020;
Baqersad et al. 2019;Liu et al. 2019;Jahangiri et al. 2019;Wei
et al. 2019;Notani et al. 2020a). It has been proved that fabricating
asphalt mixture by appropriate modified asphalt binders presents
higher moisture and aging resistance rather than using a neat
asphalt binder (Zhang et al. 2019b;Sezavar et al. 2019;
Mohammadafzali et al. 2018;Wang et al. 2018). Given the lack
of critical attention paid to evaluating the aging and moisture re-
sistance of TMA binders and mixtures, this study focused on
assessing the effect of adding waste toner to a neat asphalt binder
on the binders short-term aging and the mixturesmoisture resis-
tance based on rheological, chemical, and mechanical evaluation
approaches. In the following, a brief review of theoretical back-
grounds and methodology of aging and moisture resistance evalu-
ation is presented, then the materials and test methods, and finally
the results of experimental tests were analyzed and discussed.
Methodology Background
Asphalt Binders Aging Resistance
In this study, three methods were used to evaluate the effect of
waste toner on asphalt binder, including rheological aging index
(RAI), viscosity aging index (VAI), and chemical functional indices
obtained from Fourier transform infrared (FTIR) results on both
aged and unaged specimens, as described in the following.
RAI
The rheological behavior of neat and TMA binders is described
by using two constitutive viscoelastic parameters: complex shear
modulus (G) and phase angle (δ). Fini et al. (2016) presented a
rheological equation [Eq. (1)] associated with both parameters
to quantify the asphalt binder aging phenomenon. Note that G
and δof asphalt binders can be obtained from the frequency sweep
test based on ASTM D7552-09 (ASTM 2014a)
RAI ¼G
Aged
G
Unaged
×expðδAged δUnaged Þð1Þ
VAI
A fluids resistance of unaged to aged binders presents the effect of
aging on asphalt binder physical properties. For this purpose, it was
decided to use VAI for describing the impact of waste toner on flu-
ids resistance and analyzing the aging resistance of neat and TMA
binders before and after short-term aging [Eq. (2)].
VAI ¼ηAged
ηunaged
ð2Þ
in which η= viscosity of asphalt binder, which can be measured using
a rotational viscometer according to ASTM D4402 (ASTM 2015b).
Chemical Functional Group
Because there was no standardized test to evaluate the effect of
aging on asphalt binders, Petersen et al. (1993) used the Fourier
transform of the infrared accelerometer to assess chemical func-
tional groups before and after aging. It was shown that the aging
affects chemical functional groups identified from infrared
wave spectroscopy over a range of wavenumbers from 1,650 to
1,800 cm1. Moreover, the evidence suggests that carbonyl and
sulfoxide functional bonds are among the essential factors for
describing the impact of aging on asphalt binders, where a higher
value of those implies that the asphalt binder has aged more (Glover
2007;Petersen et al. 1993).
Yu et al. (2013) used the FTIR result to quantify the changes that
happened in the chemical functional groups of aged binders
compared to unaged binders. The results of this study showed an
increase in carbonyl and sulfoxide functional groups after experi-
encing the short- and long-term aging process. Lamontagne et al.
(2001) showed how research into infrared spectroscopy was mainly
concerned with aging by conducting a study to quantify the portion
of chemical functional groups based on the binder infrared spec-
trum obtained from FTIR. With the aim of such an approach,
Yao et al. (2013) conducted a study to investigate the variation
of chemical components before and after aging. The results proved
that the sulfoxide component of asphalt binders is not an aging
representative indicator as much as the carbonyl functional group.
The infrared spectra obtained from FTIR spectroscopy are
examined to detect chemical interatomic bonds presented in a
material by means of measuring the absorbed light at specific wave-
lengths. It should be declared that at each test frequency, each
chemical bond absorbs different intensities (Zhu et al. 2018).
An infrared spectrum consists of a sequence of absorption electro-
magnetic radiations at frequencies associated with the vibration of a
set of unique combinations of atoms and specific chemical func-
tional bonds within the asphalt binders molecules. Therefore, it
is not possible to find two components that indicate the same
set of absorptions at a specific frequency. Moreover, the intensity
of the spectrum peaks is a direct identification of the density of
chemical components of the materials (Ouyang et al. 2006). In light
of such an explanation, the intensity and baseline of the infrared
spectrum are affected by the sample thickness; the thicker sample
results in a higher absorbance value. Such an error might occur be-
cause of fabricating the FTIR specimens process, i.e., a tiny differ-
ence between the weight of the sampled asphalt binder on the
transparent KBR pills will change the whole absorbance intensifi-
cation spectrum. For the sake of avoiding the sample thickness
effect, it is possible to quantify the chemical functional group by
considering the peak intensity and spectrum baseline (Ouyang et al.
2006;Yao et al. 2013). In this regard, there are some computational
techniques for quantitative analysis; among them, a spectrometric
investigation method is a well-recognized approach for character-
izing an asphalt binders chemical functional groups. According to
this approach, it is possible to quantify the structural and functional
chemical bonds based on the confined area between two conse-
quence valleys presented on each side of the peak (Lamontagne
et al. 2001). The following equations have been used to quantify
these chemical functional groups:
Carbonyl ¼A1700
PAð3Þ
Sulfoxide ¼A1030
PAð4Þ
where
XA¼A1700 þA1600 þA1460 þA1376 þA1030 þA864
þA814 þA743 þA724 þAð2953,2923;2862Þð5Þ
and Ai= absorption bond area in the ith peak. In this research,
the amplitude wavelength of carbonyl and sulfoxide peaks
(Fig. 2) was determined as 1,6851,755 cm1and 9951,059 cm1,
respectively.
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Moisture Susceptibility
Although many researchers have introduced several approaches for
evaluating asphalt binder moisture resistance, the Superpave binder
specification does not include a method to assess binder adhesive
properties (Kanitpong and Bahia 2005;Kanitpong et al. 2006;
Hamedi et al. 2016;Arabzadeh and Guler 2019). Several test
procedures have been developed to investigate the moisture damage
resistance of HMA in the laboratory, such as Lottman (Buchanan
and Moore 2005), Root-Tunnicliff (Kennedy and Ping 1991),
modified Lottman (Apeagyei et al. 2015;Khedmati et al. 2017),
and static immersion tests (Stuart 1990). In the static immersion
test, the asphalt specimens should be placed in water for 1618 h.
Then, the percentage of visible area retained on the binder coating
is approximately measured. Although this test is simple, it is sub-
jective and does not take the mixture strength into account. In the
Lottman test, three groups of specimens representing control and
field performance at 4 and 412 years are fabricated, and then the
tensile strength ratio (TSR) is determined. The Root-Tunnicliff test
utilizes two groups of asphalt specimens: unconditioned and vac-
uum saturated. Note that in the Root-Tunnicliff test, the freeze-thaw
procedure is eliminated, which makes it different from the Lottman
test. The modified Lottman test is a combination of the Lottman
test and the Root-Tunnicliff, which has been widely accepted in
the pavement industry and standardized under AASHTO T283
(AASHTO 2014) and ASTM D4867 (ASTM 2014b). To obtain
the TSR value, the indirect tensile test should be carried out on
the unconditioned and conditioned specimens at ambient temper-
ature. The indirect tensile strength (ITS) test is performed by
applying a compressive load. The maximum load applied on the
asphalt mixture specimen at failure is obtained, and then the
ITS value for each specimen is computed using the following
equation:
ITS ¼2000f=πLD ð6Þ
where f= maximum compressive load carried by the specimen
(kN); and L and D = mean thickness and diameter of the test speci-
men (m), respectively. The TSR value is also determined as
follows:
TSR ¼PConditioned
PUnconditioned
ð7Þ
where Pi= ITS of each specimen obtained from Eq. (6). It
should be noted that according to AASHTO T283, the TSR value
must be higher than 0.7 after the specimen experiences one freeze-
thaw cycle.
Materials and Test Methods
In this section, the original asphalt binder is introduced as well as
toner-modified binders. Also, the sample preparation method of
modified asphalt binders and mixtures are presented in detail.
Materials and Modification Procedure
In this research, the original asphalt binder had a performance grade
of PG58-22. Conventional features of the original asphalt binder
are shown in Table 1. The leftover burned toner was acquired from
a central printing service center.
The original asphalt binder was modified by waste toner with a
set of dosages from 4% to 16% by weight of asphalt binder with a
4% interval. Before mixing, the original asphalt binder was pre-
heated for 1.5 h to be fluid enough for mixing with waste toner
by using a low shear mixer. The modification process was carried
out considering a 500-rpm agitation rate for 1.5 h at 163°C follow-
ing a previous research study (Notani et al. 2018). Consequently,
four modified asphalt binders were prepared at 4%, 8%, 12%, and
16% of toner content by total weight of asphalt binder and then
labeled as OB, TMA 4%, TMA 8%, TMA 12%, and TMA 16%
in which the waste toner dosage has directly appeared in the sample
code. In addition, to simulate the effect of aging, which takes place
during asphalt production and asphalt paving, neat and TMA bind-
ers were aged using the rolling thin film oven (RTFO) test follow-
ing ASTM D2872-19 (ASTM 2019).
Siliceous aggregate was used for constructing the toner-
modified asphalt mixtures (TMAM). Fig. 3shows the aggregate
gradation. Moreover, Table 2represents the conventional properties
of the aggregate. For fabricating asphalt mixture specimens, the
Fig. 2. FTIR spectrum from 600 to 2,000 cm1for neat and TMA
binders.
Table 1. Classical properties of virgin asphalt binder
Test name Value
Penetration (at 25°C), 0.1 mm 98
Softening point, °C 45
Viscosity (at 135°C), Pa · s 0.287
Ductility (at 25°C), cm þ100
Fig. 3. Aggregate gradation.
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Marshall mix design [ASTM D6927 (ASTM 2015a)] procedure
was performed to determine the optimum binder content (OBC).
The OBC was found to be 5.6% by mix weight. Then, this percent-
age was selected for fabricating all asphalt mixture specimens. The
ITS test was conducted on the specimens, which were compacted
with 50 blows on each side of the Marshall cylinder samples,
during which their air void did not exceed the specified limits
(6%8%). The asphalt mixture specimens were named OBAM,
TMAM 4%, TMAM 8%, TMAM 12%, and TMAM 16%. Three
replicates were conducted for each asphalt binder specimen.
Test Methods
Dynamic Shear Rheometer Test
A dynamic shear rheometer (DSR) was used to measure two main
viscoelastic parameters (Gand δ). Generally, an asphalt binder
consists of two molecular components which can be classified into
two categories: polar (i.e., asphaltene), which is responsible for the
elastic behavior of the binder, and nonpolar (i.e., maltene), which is
mainly subjected to its viscous behavior (Soleimani 2009). These
two molecular components are mainly responsible for the visco-
elastic behavior of the asphalt binder whereby increasing time, tem-
perature, or loading rate causes an alignment on the long-chain
flow, which is more representative of the viscous behavior of the
asphalt binder. In this study, the viscoelastic parameters were
obtained by performing a frequency sweep test at test temperatures
between 46°C and 70°C with a 6°C interval. It is worth noting that
the frequency sweep range was from 0.1 to 100 rad=s.
Rotational Viscometer Test
The viscosity of neat and TMA binders was measured via Brook-
field DDV2 (Gilson Company, Lewis Center, Ohio) for unaged and
RTFO aged conditions at test temperatures of 60°C, 135°C, and
160°C considering a rotating speed of 20 rpm.
Fourier Transform Infrared Spectroscopy (FTIR)
To obtain the infrared spectrum of specimens, an FTIR test was
adopted to quantify sulfoxide and carbonyl functional groups. For this
purpose, an ATR Bomem (Neobits, Santa Clara, California) apparatus
was employed to obtain the infrared spectra of neat and TMA binders.
ITS Test
The ITS test was conducted on unconditioned and conditioned
OBAM and TMAM specimens by applying a compressive dis-
placement at a constant rate of 50 mm=min at ambient temperature.
In this study, 45 samples were prepared for running the ITS test.
Three unconditioned and three conditioned samples were tested for
each group of asphalt mixtures. According to AASHTO T283,
50%80% of specimen air voids should be saturated by distilled
water. For this purpose, they were vacuum saturated and were
then placed in waterproof plastic bags with 10 mL of distilled
water before freezing. Eventually, the saturated neat and toner-
modified asphalt mixture specimens were exposed to one and three
freeze-thaw cycles. Each cycle consisted of freezing for 16 h at
18°C and then immediately being placed in a 60°C water bath
for 24 h. Before performing the ITS test, the specimens were placed
in a 25°C water bath for 1 h.
Results and Discussion
Aging Resistance
Figs. 4(a and b) show the complex shear modulus of neat and modi-
fied asphalt binders for unaged and RTFO aged conditions. As can
be seen in these figures, adding waste toner to original asphalt bind-
ers increases the complex shear modulus, and extending the waste
toners dosage up to 12% results in the highest Gcompared to
other dosages. Moreover, at lower temperatures such as 46°C, a
considerable raise in complex shear modulus was achieved. Con-
sistently, Figs. 4(c and d) indicate changes in the phase angle versus
test temperature. It is observed that the lower phase angle corre-
sponds to TMA 12%, which implies that TMA 12% has a better
elastic capability compared to lower and higher dosages of toner.
It can be justified with the concept that rising test temperature
decreases the elastic properties of the asphalt binder, and conse-
quently, the viscous portion of the asphalt binder is more dominant.
Such an improvement might be related to toner compositions in
which the waste toner consists of styrene acrylate/styrene buta-
diene, polyester, and a couple more semiheavy copolymers (Notani
et al. 2019) that results in a binder with a polymer-rich phase. Intro-
ducing styrene acrylate/styrene butadiene and resin polyester into
the asphalt binder makes crystallite crosslinks that affect the binder
complex modulus (Fawcett and McNally 2001). Such an explan-
ation would support the higher complex modulus of TMA binders
compared to the original one.
However, analyzing the complex shear modulus and the phase
angle individually could not explain the role of waste toner additive
on the asphalt binders aging resistance. For this reason, the RAI
was introduced and selected as an aging indicator.
RAI
The RAI value is an indicator of the rheological aging resistance of
an asphalt binder that experienced the aging process. The aim of
using this index is to assess the combination of complex shear
modulus and phase angle with rheological properties of neat and
TMA binders for evaluating aging resistance. In this way, the lower
value of RAI indicates that the binder is less affected by aging. The
results of RAI are exhibited in Fig. 5. According to data presented
in this figure, it can be perceived that by raising the test temper-
ature, the RAI index increases. This indicates that at high temper-
atures, the role of light binder constituents is more prevalent than
the asphaltene portion. From this attitude, it could be conceivably
concluded that the RAI value is more representative at higher tem-
peratures for assessing the effect of aging. Further, it can be sup-
ported by the prevalence of binder sol-gel (Padmarekha and
Krishnan 2011) behavior at intermediate temperatures. From this
figure, it can be seen that modifying a binder with 4% of waste
toner shows better aging resistance in all test temperatures in which
the aging index for a modified binder containing more than 8% of
waste toner is more than the original binder at 46°C, while an
opposite trend was observed at 64°C. This discrepancy can be ex-
plained by the proximity of high-temperature grading of the origi-
nal asphalt binder (58°C) to the test temperature.
Due to the fact that in the short-term aging process the polar
aromatic is transformed into asphaltenes (Liu et al. 2017), the aged
asphalt binder is stiffer in comparison with the unaged binder due to
the presence of a low amount of aromatics. Because the TMA
Table 2. Conventional physical properties of aggregate
Test Value
Specification
limits
Bulk specific gravity
Coarse aggregate (g=cm3) 2.589
Fine aggregate 2.610
Filler 2.62
Flat and elongated particles, % 5.4 Max 10
Los Angeles abrasion, % 22 Max 45
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binders contain a lower light fraction, they showed lower aging re-
sistance compared to the toner-modified binders at high tempera-
tures. As can be seen, for a high dosage of waste toner (i.e., 16%),
the trend changes, which can be attributed to the central aim of
another study conducted by the authors that proved that TMA
16% presented phase segregation because of the high molecular
weight of waste toner (Notani et al. 2019).
VAI
The VAI value for all binders is exhibited in Fig. 6. This index
was obtained by dividing the viscosity of the aged binder by the
viscosity of the unaged binder. As shown in Fig. 6(a), the TMA
4% presents a lower VAI than other samples at 60°C. Increasing
the test temperature causes a reduction in the VAI value. It can
be related to the role of toner ingredients within the binder struc-
ture. The waste toner has copolymers that interact with the light
portions of the binder, which reduces the probability of volatiliza-
tion of light portions during the RTFO process. This attitude can be
supported by the difference between VAI and temperature shown in
Fig. 6. The waste toner copolymers fortify the bond between the
binders light portions and toner ingredients that enhance the vola-
tilization resistance of the modified binder in the RTFO process.
Chemical Functional Group
As mentioned in the introduction and background section, two im-
portant compounds in the aging phenomena can be distinguished
by the presence and progression of carbonyl and sulfoxide func-
tional groups around wavenumbers of 1,700 and 1,030 cm1, re-
spectively (Fig. 2). To quantify these two functional groups, the
intensity peak of the absorption spectrum and its amplitude around
these wavenumbers were determined first, and then the area under
the absorption graph was calculated between the peak amplitudes.
The results of these experiments are shown for the unaged and aged
binder in Figs. 7(a and b), respectively. To obtain the amount of
carbonyl group, the amplitude of this group between wavenumbers
was determined to be 1,6851,755 cm1, and for the sulfoxide
Fig. 4. Rheological properties of neat and toner-modified binders versus test temperature at 1.59 Hz, including: (a) complex shear modulus at unaged
condition; (b) complex shear modulus at RTFO aged condition; (c) phase angle at unaged condition; and (d) phase angle at RTFO aged condition.
Fig. 5. RAI of original and modified asphalt binders at loading
frequency of 10 rad=s.
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group it was determined to be between 995 and 1,059 cm1. Then,
according to Eqs. (5) and (6), the values of these functional groups
were calculated.
Regarding Figs. 6and 7, it can be conceived that adding waste
toner to the original binder creates additional chemical bonds that
amplify the carbonyl and sulfoxide peaks intensity. However, these
figures cannot be analyzed solely due to the change of absorption
intensity for all binders. Therefore, it was decided to quantify the
carbonyl and sulfoxide functional groups according to Eqs. (3) and
(4), obtained from a study conducted by Lamontagne et al. (2001).
Fig. 8shows the increased percentage of two main chemical func-
tional groups after aging. It is apparent from this figure that the
binder modified with 4% of toner has the lowest percentage of
change in the amount of carbonyl and sulfoxide groups, which im-
plies the idea that the addition of toner up to 4% improves short-
term aging resistance.
Moisture Susceptibility
Results of Experimental Tests of Original and
Toner-Modified Binders
Fig. 9presents the carbonyl (CO) and sulfoxide (SO) functional
group values for the unaged binders. Fig. 9indicates that by raising
the waste toners dosage, the carbonyl functional group achieved a
small increment. On the other hand, by increasing the toners
dosage up to 12%, the value of the sulfoxide functional group de-
creased and then for a further amount increased. The sulfoxide
functional group is more useful than the carbonyl group for evalu-
ating the moisture sensitivity of the asphalt binder, where a lower
value of sulfoxide functional group represents higher moisture
damage resistance (Ahmad et al. 2018). In light of this fact, the
moisture damage resistance is expected to improve by extending
the waste toner dosage up to 12% due to sulfoxide functional group
reduction.
Fig. 6. VAI value versus test temperature for neat and TMA binders: (a) VAI value; and (b) VAI trend.
Fig. 7. Result of FTIR test for neat and TMA binders: (a) unaged condition; and (b) aged condition.
Fig. 8. Chemical functional group value for neat and toner-modified
binders.
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As can be observed, TMA 12% is a milestone because a diverse
trend was demonstrated by extending the modifiers dosage. In-
deed, by increasing the waste toner dosage more than 12%, the
probability of phase segregation is increased. This can be explained
by increasing the molecular weight of modified asphalt binder due
to the presence of a high amount of styrene acrylate copolymer with
high molecular weight and iron oxide with higher relative density
than asphalt binder. As a result, by adding more waste toner to the
blend, deposition of heavy molecules might take place, which can
disturb the stability of asphaltene and maltene phases.
Results of Experimental Tests of Original and
Toner-Modified Asphalt Mixtures
To verify the findings obtained from the FTIR test analysis, an ITS
test was performed on TMA mixtures. Fig. 10 shows the mean ITS
of three replicates on conditioned and unconditioned specimens. As
can be seen in this figure, by increasing the waste toner dosage up
to 12%, the ITS value increases for both conditioned and uncon-
ditioned specimens, and then it decreases. This could be related to
the same explanation provided for Fig. 9, in which TMA 16% has
the highest molecular weight, which increases the probability of
segregation of the asphalt binders phase.
Fig. 11 illustrates the TSR value for original and TMA mixtures.
It can be seen that TSR increases with an increase in waste toner
dosage. However, it attains its maximum value when 16% of waste
toner is added to the original binder. Therefore, it can be concluded
that 12% of waste toner is more recommended in comparison with
higher percentages considering the ITS value for unconditioned
and conditioned specimens shown in Fig. 10. It is probable that
at a concentration of about 12% of waste toner, the asphalt binder
is saturated, and therefore higher amounts of the waste cannot react
with the asphalt binder and will be sedimented.
The next purpose of this study is to evaluate the effect of waste
toner on the moisture sensitivity of conditioned specimens, which
have passed three freeze-thaw cycles. As can be seen in Fig. 12, the
specimens were demolished after three cycles. However, it can be
seen that TMAM 12% and TMAM 16% have a better configuration
in that the waste toner causes more adhesion among the aggregates.
This can be related to the fact that the toner has a polyester resin
which may enhance the adhesive interaction between aggregates
and the asphalt binder [Yamasaki et al. Polyester resin for toner,
toner, developer, toner cartridge, process cartridge, and image
forming apparatus,US Patent No. 8,628,902 (2014)].
Comparing the results obtained for asphalt binders with mix-
tures results, it can be observed that the sulfoxide functional group
gives a better understanding of the asphalt binders moisture resis-
tance than the carbonyl functional group, because TMAM 12% has
the highest ITS value and also better condition and integrity among
Fig. 9. Values of sulfoxide and carbonyl group functions.
Fig. 10. ITS test results for neat and toner-modified asphalt mixtures.
Fig. 11. TSR for original and toner-modified asphalt mixtures.
Fig. 12. TMAM and OBAM specimens after experiencing three
freeze-thaw cycles.
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other specimens. The other consideration related to the amount of
waste toner is that increasing the waste toner dosage up to a specific
amount decreases the compatibility of two phases (asphaltene and
maltene), and consequently, the probability of intercepting them
increases. Moreover, regarding the complex multiphase system
of asphalt binders and high density of iron oxide within the waste
toner, if the waste toner percentage exceeds a specific amount of
12%, the colloidal structure of the modified asphalt binder may be
interrupted, which leads to deposition of heavy molecules and sup-
plementary nonreacted molecules of toner.
Conclusions
Every year, a large amount of produced toner becomes waste from
production and printing processes. This waste material is currently
landfilled because there is no utilization for them. Also, one of the
crucial current environmental issues is to provide sustainable
material for construction. The application of waste toner as an as-
phalt binders modifier can eliminate associated ecological prob-
lems. Moreover, intending to promote polymer-modified asphalt
binder for asphalt roadways, it is possible to modify original
asphalt binders with carbon-based materials for rheological and
mechanical enhancement. Because waste toner has carbon- and
polymer-based components, it can be a useful additive for enhanc-
ing rheological and mechanical properties of original asphalt bind-
ers and mixtures. Therefore, there are two primary aims for this
study: (1) to examine the effect of waste toner on short-term aging
resistance of bituminous material, and (2) to determine the moisture
resistance of toner-modified binders and mixtures. For the former
objective, three methods were employed in this research, including
RAI, VAI, and chemical aging index based on the infrared spectra
of original and TMA binders. For moisture resistance, the FTIR
results were also used to investigate the effect of waste toner on
chemical functional groups and the TSR of both conditioned and
unconditioned mixture specimens. The findings of this study led to
the following conclusions:
The VAI could not give a detailed overview for evaluating the
aging resistance of asphalt binder because it highly depends on
the test temperature, and also, at higher temperatures many of
the modifier ingredients are melted.
The finding of RAI recommends using this index for tempera-
tures lower than the high service temperature of asphalt binders
to ensure the accuracy of the results.
Chemical functional group bonds are more representative than
other indices, because the aging phenomena is an intrinsic prop-
erty and the analysis of carbonyl (CO) and sulfoxide (SO)
functional groups gives more accurate insight about aging resis-
tance as they are not dependent on loading rate and test
temperature.
The TMA mixtures represent better performance in coping with
freeze-thaw cycles, as TMAM 12% illustrated higher moisture
damage resistance among all specimens fabricated with original
and modified asphalt binders.
TMAM 12% and TMAM 16% remained intact when they
experienced three freeze-thaw cycles because the adhesion be-
tween the binder-aggregate system was improved due to an
increase in polyester resin within the specimens.
Regarding evaluations performed in this research study, it can
be concluded that the optimum and recommended dosage for
waste toner is about 12%. For higher dosages, the modified binder
shows an undesirable behavior against moisture damage. Substitut-
ing some portion of the original asphalt binder with waste
toner as a modifier can be an appropriate solution for solving its
environmental problem as well as reducing the cost of asphalt mix-
ture production.
Because there is no comprehensive state of the art on the per-
formance of TMA binders and mixtures, it is recommended to
evaluate the long-term aging resistance and moisture susceptibility
of toner-modified asphalt binders through nanoscale tests such as
atomic force microscopy (AFM) and surface energy method,
respectively. Furthermore, it is suggested to use the balance mix
design method as a future study for evaluating mechanical proper-
ties of TMAM.
Data Availability Statement
The authors declare that all data, models, and code generated or
used during the study appear in the published article.
Acknowledgments
This paper was prepared from a study conducted at Amirkabir
University of Technology as a part of the research performed by
the authors.
References
AASHTO. 2014. Standard method of test for resistance of compacted as-
phalt mixtures to moisture-induced damage. AASHTO T283. West
Conshohocken, PA: ASTM.
Ahmad, M., U. A. Mannan, M. R. Islam, and R. A. Tarefder. 2018. Chemi-
cal and mechanical changes in asphalt binder due to moisture condition-
ing.Road Mater. Pavement Des. 19 (5): 12161229. https://doi.org/10
.1080/14680629.2017.1299631.
Alsalihi, M., A. Hosseini, and A. Faheem. 2017. Direct characterization of
aging diffusion in asphalt mixtures using micro-indentation and relax-
ation (MIR).In Proc., Int. Conf. on Highway Pavements and Airfield
Technology 2017. Reston, VA: ASCE.
Apeagyei, A. K., J. R. Grenfell, and G. D. Airey. 2015. Influence of ag-
gregate absorption and diffusion properties on moisture damage in as-
phalt mixtures.Supplement, Road Mater. Pavement Des. 16 (S1):
404422. https://doi.org/10.1080/14680629.2015.1030827.
Arabzadeh, A., and M. Guler. 2019. Thermal fatigue behavior of
asphalt concrete: A laboratory-based investigation approach.Int. J.
Fatigue 121 (Apr): 229236. https://doi.org/10.1016/j.ijfatigue.2018
.11.022.
Arambula, E., E. J. Garboczi, E. Masad, and E. Kassem. 2010. Numerical
analysis of moisture vapor diffusion in asphalt mixtures using digital
images.Mater. Struct. 43 (7): 897911. https://doi.org/10.1617
/s11527-009-9554-3.
ASTM. 2014a. Standard test method for determining the complex shear
modulus (G*) of bituminous mixtures using dynamic shear rheometer.
ASTM D7552-09. West Conshohocken, PA: ASTM.
ASTM. 2014b. Standard test method for effect of moisture on asphalt con-
crete paving mixtures. D4867/D4867M-09. West Conshohocken, PA:
ASTM.
ASTM. 2015a. Standard test method for marshall stability and flow of as-
phalt mixtures. ASTM D6927-15. West Conshohocken, PA: ASTM.
https://doi.org/10.1520/D6927-15.
ASTM. 2015b. Standard test method for viscosity determination of asphalt
at elevated temperatures using a rotational viscometer. ASTM D4402/
D4402M-15. West Conshohocken, PA: ASTM. https://doi.org/10.1520
/D440_D4402M-15.
ASTM. 2019. Standard test method for effect of heat and air on a moving
film of asphalt (rolling thin-film oven test). ASTM D2872-19. West
Conshohocken, PA: ASTM. https://doi.org/10.1520/D2872-19.
Azarion, Y., H. Shirmohammadi, G. H. Hamedi, and D. Saedi. 2019.
Model for predicting moisture susceptibility of asphalt mixtures based
© ASCE 04020405-9 J. Mater. Civ. Eng.
J. Mater. Civ. Eng., 2021, 33(1): 04020405
Downloaded from ascelibrary.org by Mohammad Ali Notani on 10/20/20. Copyright ASCE. For personal use only; all rights reserved.
on material properties.J. Mater. Civ. Eng. 31 (10): 04019239. https://
doi.org/10.1061/(ASCE)MT.1943-5533.0002882.
Baqersad, M., H. Ali, F. Haddadi,and I. Khakpour. 2019. Short- and long-
term rheological and chemical characteristics of nanomodified asphalt
binder.Pet. Sci. Technol. 37 (15): 17881799. https://doi.org/10.1080
/10916466.2019.1602635.
Buchanan, M. S., and V. M. Moore. 2005. Laboratory accelerated strip-
ping simulator for hot mix asphalt. Rep. No. FHWA/MS-DOT-RD-04-
167. Starkville, MS: Mississippi State Univ.
Cavalli, M. C., M. Zaumanis, E. Mazza, M. N. Partl, and L. D. Poulikakos.
2018. Aging effect on rheology and cracking behaviour of reclaimed
binder with bio-based rejuvenators.J. Cleaner Prod. 189 (Jul): 8897.
https://doi.org/10.1016/j.jclepro.2018.03.305.
Corbett, L., and H. Schweyer. 1981. Composition and rheology consid-
erations in age hardening of bitumen.In Proc., Association of Asphalt
Paving Technologists. Washington, DC: Transportation Research
Board.
Epps, J. A. 2000. Compatibility of a test for moisture-induced damage with
Superpave volumetric mix design. National Cooperative Highway
Research Program Rep. No. 444. Washington, DC: Transportation
Research Board.
Fawcett, A. H., and T. McNally. 2001. Blends of bitumen with polymers
having a styrene component.Polym. Eng. Sci. 41 (7): 12511264.
https://doi.org/10.1002/pen.10826.
Fini, E. H., P. Hajikarimi, M. Rahi, and F. Moghadas Nejad. 2016. Phys-
iochemical, rheological, and oxidative aging characteristics of asphalt
binder in the presence of mesoporous silica nanoparticles.J. Mater.
Civ. Eng. 28 (2): 04015133. https://doi.org/10.1061/(ASCE)MT.1943
-5533.0001423.
Glover, I. C. 2007. Wet and dry aging of polymer-asphalt blends:
Chemistry and performance.Doctoral dissertation, Dept. of Chemistry,
Louisiana State Univ.
Grenfell, J., N. Ahmad, Y. Liu, A. Apeagyei, D. Large, and G. Airey. 2014.
Assessing asphalt mixture moisture susceptibility through intrinsic
adhesion, bitumen stripping and mechanical damage.Road Mater.
Pavement Des. 15 (1): 131152. https://doi.org/10.1080/14680629
.2013.863162.
Haghshenas, H. F., R. Rea, D. Byre, D. F. Haghshenas, G. Reinke, and M.
Zaumanis. 2020. Asphalt binder laboratory short-term aging: Effective
parameters and new protocol for testing.J. Mater. Civ. Eng. 32 (1):
04019327. https://doi.org/10.1061/(ASCE)MT.1943-5533.0002978.
Hamedi, G. H., F. M. Nejad, and K. Oveisi. 2016. Estimating the
moisture damage of asphalt mixture modified with nano zinc oxide.
Mater. Struct. 49 (4): 11651174. https://doi.org/10.1617/s11527
-015-0566-x.
Jahangiri, B., H. Majidifard, J. Meister, and W. G. Buttlar. 2019. Perfor-
mance evaluation of asphalt mixtures with reclaimed asphalt pavement
and recycled asphalt shingles in Missouri.Transp. Res. Rec. 2673 (2):
392403. https://doi.org/10.1177/0361198119825638.
Kanitpong, K., and H. Bahia. 2005. Relating adhesion and cohesion of
asphalts to the effect of moisture on laboratory performance of asphalt
mixtures.Transp. Res. Rec. 1901 (1): 3343. https://doi.org/10.1177
/0361198105190100105.
Kanitpong, K., D.-W. Cho, and H. Bahia. 2006. Effect of additives on
performance of asphalt mixtures.Proc. Inst. Civ. Eng. Constr. Mater.
159 (3): 103110. https://doi.org/10.1680/coma.2006.159.3.103.
Kennedy, T. W., and W. V. Ping. 1991. Comparison study of moisture
damage test methods for evaluating antistripping treatments in asphalt
mixtures.Transp. Res. Rec. 1323: 94111.
Khedmati, M., A. Khodaii, and H. Haghshenas. 2017. A study on moisture
susceptibility of stone matrix warm mix asphalt.Constr. Build. Mater.
144 (Jul): 4249. https://doi.org/10.1016/j.conbuildmat.2017.03.121.
Kim, Y. R., C. Castorena, Y. Wang, A. Ghanbari, and J. Jeong. 2018. Com-
paring performance of full-depth asphalt pavements and aggregate
base pavements in NC. Rep. No. FHWA/NC/2015-02. Raleigh, NC:
NCDOT.
Lamontagne, J., P. Dumas, V. Mouillet, and J. Kister. 2001. Comparison
by Fourier transform infrared (FTIR) spectroscopy of different ageing
techniques: Application to road bitumens.Fuel 80 (4): 483488.
https://doi.org/10.1016/S0016-2361(00)00121-6.
Liu, H., L. Fu, Y. Jiao, J. Tao, and X. Wang. 2017. Short-term aging effect
on properties of sustainable pavement asphalts modified by waste
rubber and diatomite.Sustainability 9 (6): 996. https://doi.org/10
.3390/su9060996.
Liu, S., A. Peng, S. Zhou, J. Wu, W. Xuan, and W. Liu. 2019. Evaluation
of the ageing behaviour of waste engine oil-modified asphalt binders.
Constr. Build. Mater. 223 (Oct): 394408. https://doi.org/10.1016/j
.conbuildmat.2019.07.020.
Lu, X., and U. Isacsson. 2000. Artificial aging of polymer modified bitu-
mens.J. Appl. Polym. Sci. 76 (12): 18111824. https://doi.org/10.1002
/(SICI)1097-4628(20000620)76:12<1811::AID-APP12>3.0.CO;2-1.
Malakooti, A., M. Maguire, and R. J. Thomas. 2018. Evaluating electrical
resistivity as a performance based test for Utah bridge deck concrete.
Rep. No. CAIT-UTC-NC35. Piscataway, NJ: Center for Advanced
Infrastructure and Transportation, Rutgers Univ.
Mohammadafzali, M., H. Ali, G. A. Sholar, W. A. Rilko, and M. Baqersad.
2018. Effects of rejuvenation and aging on binder homogeneity of re-
cycled asphalt mixtures.J. Transp. Eng. Part B: Pavements
145 (1): 04018066. https://doi.org/10.1061/JPEODX.0000089.
Nakhaei, M., K. Naderi, A. A. Nasrekani, and D. H. Timm. 2018. Mois-
ture resistance study on PE-wax and EBS-wax modified warm mix as-
phalt using chemical and mechanical procedures.Constr. Build. Mater.
189 (Nov): 882889. https://doi.org/10.1016/j.conbuildmat.2018.08
.216.
Notani, M. A., A. Arabzadeh, S. Satvati, M. T. Tabesh, N. G. Hashjin, S.
Estakhri, and M. Alizadeh. 2020a. Investigating the high-temperature
performance and activation energy of carbon black-modified asphalt
binder.SN Appl. Sci. 2 (2): 303. https://doi.org/10.1007/s42452-020
-2102-z.
Notani, M. A., P. Hajikarimi, F. M. Nejad, and A. Khodaii. 2020b. Rutting
resistance of toner-modified asphalt binder and mixture.Int. J. Pave-
ment Res. Technol. 13 (1): 19. https://doi.org/10.1007/s42947-019
-0131-z.
Notani, M. A., F. Moghadas Nejad, E. H. Fini, and P. Hajikarimi. 2019.
Low-temperature performance of toner-modified asphalt binder.
J. Transp. Eng. Part B: Pavements 145 (3): 04019022. https://doi
.org/10.1061/JPEODX.0000123.
Notani, M. A., F. Moghadas Nejad, A. Khodaii, and P. Hajikarimi. 2018.
Evaluating fatigue resistance of toner-modified asphalt binders using
the linear amplitude sweep test.Road Mater. Pavement Des. 20 (8):
19271940. https://doi.org/10.1080/14680629.2018.1474792.
Notani, M. A., and M. Mokhtarnejad. 2018. Investigating the rheological
and self-healing capability of toner-modified asphalt binder.Proc. Inst.
Civ. Eng. Constr. Mater. 173 (3): 123131. https://doi.org/10.1680
/jcoma.17.00072.
Ouyang, C., S. Wang, Y. Zhang, and Y. Zhang. 2006. Improving the aging
resistance of asphalt by addition of zinc dialkyldithiophosphate.Fuel
85 (78): 10601066. https://doi.org/10.1016/j.fuel.2005.08.023.
Padmarekha, A., and J. M. Krishnan. 2011. Experimental investigation on
solgel transition of asphalt.Int. J. Adv. Eng. Sci. Appl. Math. 3(14):
131139. https://doi.org/10.1007/s12572-011-0048-5.
Pérez, I., A. Pasandín, and J. Gallego. 2012. Stripping in hot mix
asphalt produced by aggregates from construction and demolition
waste.Waste Manage. Res. 30 (1): 311. https://doi.org/10.1177
/0734242X10375747.
Petersen, J. C. 2000. Chemical composition of asphalt as related to asphalt
durability.In Vol. 40 of Developments in petroleum science, 363399.
Amsterdam, Netherlands: Elsevier.
Petersen, J. C. 2009. A review of the fundamentals of asphalt oxidation:
Chemical, physicochemical, physical property, and durability relation-
ships.Transp. Res. Circ. (E-C140): 78. https://doi.org/10.17226
/23002.
Petersen, J. C., J. F. Branthaver, R. E. Robertson, P. M. Harnsberger, J. J.
Duvall, and E. K. Ensley. 1993. Effects of physicochemical factors on
asphalt oxidation kinetics.Transp. Res. Rec. (1391): 110.
Pouranian, M. R., and J. E. Haddock. 2019. A new framework for under-
standing aggregate structure in asphalt mixtures.Int. J. Pavement Eng.
117. https://doi.org/10.1080/10298436.2019.1660340.
Pouranian, M. R., M. A. Notani, M. T. Tabesh, B. Nazeri, and M.
Shishehbor. 2020. Rheological and environmental characteristics of
© ASCE 04020405-10 J. Mater. Civ. Eng.
J. Mater. Civ. Eng., 2021, 33(1): 04020405
Downloaded from ascelibrary.org by Mohammad Ali Notani on 10/20/20. Copyright ASCE. For personal use only; all rights reserved.
crumb rubber asphalt binders containing non-foaming warm mix as-
phalt additives.Constr. Build. Mater. 238 (Mar): 117707. https://doi
.org/10.1016/j.conbuildmat.2019.117707.
Pouranian, M. R., and M. Shishehbor. 2019. Sustainability assessment of
green asphalt mixtures: A review.Environments 6 (6): 73. https://doi
.org/10.3390/environments6060073.
Qian, G., H. Yu, X. Gong, and L. Zhao. 2019. Impact of nano-TiO2on the
NO2degradation and rheological performance of asphalt pavement.
Constr. Build. Mater. 218 (Sep): 5363. https://doi.org/10.1016/j
.conbuildmat.2019.05.075.
Rahbar-Rastegar, R., R. Zhang, J. E. Sias, and E. V. Dave. 2019. Evalu-
ation of laboratory ageing procedures on cracking performance of
asphalt mixtures.Supplement, Road Mater. Pavement Des. 20 (S2):
S647S662. https://doi.org/10.1080/14680629.2019.1633782.
Rahmani, H., H. Shirmohammadi, and G. H. Hamedi. 2018. Effect of as-
phalt binder aging on thermodynamic parameters and its relationship
with moisture sensitivity of asphalt mixes.J. Mater. Civ. Eng.
30 (11): 04018278. https://doi.org/10.1061/(ASCE)MT.1943-5533
.0002453.
Roberts, F. L., P. S. Kandhal, E. R. Brown, D. Y. Lee, and T. W. Kennedy.
1991. Hot mix asphalt materials, mixture design and construction.
Lanham, MD: National Asphalt Pavement Association Research and
Education Foundation.
Sezavar, R., G. Shafabakhsh, and S. M. Mirabdolazimi. 2019. New model
of moisture susceptibility of nano silica-modified asphalt concrete using
GMDH algorithm.Constr. Build. Mater. 211 (Jun): 528538. https://
doi.org/10.1016/j.conbuildmat.2019.03.114.
Shishehbor, M., M. R. Pouranian, and M. G. Ramezani. 2019. Molecular
investigations on the interactions of graphene, crude oil fractions and
mineral aggregates at low, medium and high temperatures.Pet. Sci.
Technol. 37 (7): 804811. https://doi.org/10.1080/10916466.2019
.1566254.
Solaimanian, M., T. W. Kennedy, and R. Tripathi. 1998. Performance char-
acteristics of asphalt binders and mixtures modified by waste toner.
Transp. Res. Rec. 1638 (1): 120128. https://doi.org/10.3141/1638-14.
Soleimani, A. 2009. Use of dynamic phase angle and complex modulus for
the low temperature performance grading of asphalt cements.
Kingston, ON: Queens Univ.
Stuart, K. D. 1990. Moisture damage in asphalt mixturesAstate-of-the-
art report. Rep. No. FHWA/RD-90-019. Washington, DC: Federal
Highway Administration.
Vila-Cortavitarte, M., P. Lastra-González, M. Á. Calzada-Pérez, and I.
Indacoechea-Vega. 2018. Analysis of the influence of using recycled
polystyrene as a substitute for bitumen in the behaviour of asphalt con-
crete mixtures.J. Cleaner Prod. 170 (Jan): 12791287. https://doi.org
/10.1016/j.jclepro.2017.09.232.
Wang, H., X. Liu, P. Apostolidis, and T. Scarpas. 2018. Review of warm
mix rubberized asphalt concrete: Towards a sustainable paving
technology.J. Cleaner Prod. 177 (Mar): 302314. https://doi.org/10
.1016/j.jclepro.2017.12.245.
Wang, R., J. Yue, R. Li, and Y. Sun. 2019a. Evaluation of aging resistance
of asphalt binder modified with graphene oxide and carbon nanotubes.
J. Mater. Civ. Eng. 31 (11): 04019274. https://doi.org/10.1061/(ASCE)
MT.1943-5533.0002934.
Wang, Y. D., A. Ghanbari, B. S. Underwood, and Y. R. Kim. 2019b.
Development of a performance-volumetric relationship for asphalt
mixtures.Transp. Res. Rec. 2673 (6): 416430. https://doi.org/10
.1177/0361198119845364.
Wei, C., H. Duan, H. Zhang, and Z. Chen. 2019. Influence of SBS modi-
fier on aging behaviors of SBS-modified asphalt.J. Mater. Civ. Eng.
31 (9): 04019184. https://doi.org/10.1061/(ASCE)MT.1943-5533
.0002832.
Yao, H., Z. You, L. Li, S. W. Goh, C. H. Lee, Y. K. Yap, and X. Shi. 2013.
Rheological properties and chemical analysis of nanoclay and carbon
microfiber modified asphalt with Fourier transform infrared spectros-
copy.Constr. Build. Mater. 38 (Jan): 327337. https://doi.org/10
.1016/j.conbuildmat.2012.08.004.
Yeganeh, S. F., A. Mahmoudzadeh, M. A. Azizpour, and A. Golroo. 2019.
Validation of smartphone based pavement roughness measures.Pre-
print, submitted February 27, 2019. https://arxiv.org/abs/1902.10699.
Yildirim, Y., D. Hazlett, and R. Davio. 2004. Toner-modified asphalt dem-
onstration projects.Resour. Conserv. Recycl. 42 (3): 295308. https://
doi.org/10.1016/j.resconrec.2004.04.008.
Yildirim, Y., and T. W. Kennedy. 2003. Binder designs for the toner-
modified asphalt demonstration projects. Performing Organization
Code 7. Austin, TX: Center for Transportation Research.
Yu, X., Y. Wang, Y. Luo, and L. Yin. 2013. The effects of salt on rheo-
logical properties of asphalt after long-term aging.Sci. World J.
2013: 9. https://doi.org/10.1155/2013/921090.
Zhang, J., G. D. Airey, J. Grenfell, and A. K. Apeagyei. 2017. Moisture
damage evaluation of aggregatebitumen bonds with the respect of
moisture absorption, tensile strength and failure surface.Road Mater.
Pavement Des. 18 (4): 833848. https://doi.org/10.1080/14680629
.2017.1286441.
Zhang, R., J. E. Sias, E. V. Dave, and R. Rahbar-Rastegar. 2019a. Impact
of aging on the viscoelastic properties and cracking behavior of asphalt
mixtures.Transp. Res. Rec. 2673 (6): 406415. https://doi.org/10.1177
/0361198119846473.
Zhang, R., Z. You, H. Wang, M. Ye, Y. K. Yap, and C. Si. 2019b. The
impact of bio-oil as rejuvenator for aged asphalt binder.Constr. Build.
Mater. 196 (Jan): 134143. https://doi.org/10.1016/j.conbuildmat.2018
.10.168.
Zhu, W., X. Chen, L. J. Struble, and E.-H. Yang. 2018. Characterization of
calcium-containing phases in alkali-activated municipal solid waste in-
cineration bottom ash binder through chemical extraction and deconvo-
luted Fourier transform infrared spectra.J. Cleaner Prod. 192 (Aug):
782789. https://doi.org/10.1016/j.jclepro.2018.05.049.
© ASCE 04020405-11 J. Mater. Civ. Eng.
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... Loss of cohesion happens when the asphalt concrete mastic softens. These mechanisms are interconnected, so a pavement affected by moisture damage may display these effects in combination [4][5][6][7][8][9][10][11]. Several studies have indicated that the driving load leads to a negative-pressure pumping action that continuously scours the interface between the asphalt and aggregate, accelerating the stripping of the asphalt layer from the aggregate surface. ...
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The aim of this research is to evaluate the ageing behaviour of waste engine oil (WEO)-modified asphalt binders. Conventional properties, rheological characteristics and microscopic features were tested on the aged residues through rolling thin film oven, pressure ageing vessel and double PAV test. Results demonstrate reveal that ageing improves the high temperature performance, reduces the low temperature and fatigue performances of asphalt, while introducing WEO into asphalt significantly improves its ageing resistance. Fourier transform infrared spectroscopy (FTIR) and atomic force microscopy (AFM) results further reveal that WEO can efficiently reduce the oxygen ageing effect by supplying lightweight components.
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