Evaluation of effect of curing time on mixture performance of Advera warm mix asphalt

Construction and Building Materials 145 (2017) 62–67

Contents lists available at ScienceDirect

Construction and Building Materials journal homepage: www.elsevier.com/locate/conbuildmat

Evaluation of effect of curing time on mixture performance of Advera warm mix asphalt Shenghua Wu a,⇑, Xiaojun Li b a b

Department of Civil and Environmental Engineering, University of Illinois at Urbana-Champaign, 205 N Mathews Ave., Urbana, IL 61801, USA California State University, Fresno, CA, USA

h i g h l i g h t s
Three different curing time: 2 weeks, 1 month, and 2 months were tested.
Material properties of the Advera mix changes with curing time.
It is critical to evaluate the Advera mix at appropriate curing time.

a r t i c l e

i n f o

Article history: Received 21 February 2017 Received in revised form 28 March 2017 Accepted 31 March 2017

Keywords: Advera Warm mix asphalt Hot mix asphalt Curing time Performance

a b s t r a c t Foaming warm mix asphalt (WMA) is a green asphalt technology that has been widely used in recent years. This study evaluates the effect of curing time on the material properties of Advera foaming, as compared to hot mix asphalt (HMA) mix. Test specimens were tested at three different curing time: 2 weeks, 1 month, and 2 months after compaction. WMA performance tests, including dynamic modulus, flow number, moisture resistance, fatigue and thermal cracking resistance, were conducted for both HMA and Advera mixes. Based on the laboratory results it was found that the material properties of the Advera mix changes with curing time. As such, it is critical to evaluate the Advera mix at appropriate curing time. Ó 2017 Elsevier Ltd. All rights reserved.

1. Introduction Warm mix asphalt (WMA) is a green technology that has been widely used in asphalt community. Many WMA types are available in the market. They are generally divided into three categories: organic additive, chemical additive, and asphalt foaming process by introducing moisture [1]. All of these WMA types aim in reducing viscosity of asphalt binder so as to reduce production temperature, and thus create a better working condition at asphalt plant and paving site [2–5]. The foaming technology can be further categorized depending on the water percentage: water-based and water-containing. The water-containing foaming, also called water-bearing [6], contains approximately 20% water in the additive, such as Aspha-min, Advera. When the water-containing additive is added into the hot asphalt, the water will be released and the foamed asphalt is created. The water-based foaming technology uses a small amount of water and inject it into the asphalt

⇑ Corresponding author. E-mail addresses: [email protected] (S. Wu), [email protected] (X. Li). http://dx.doi.org/10.1016/j.conbuildmat.2017.03.240 0950-0618/Ó 2017 Elsevier Ltd. All rights reserved.

via a nozzle, such as Astec Double Barrel Green, Aquablack. The water turns into steam and expands the volume of asphalt, and thus reduce asphalt’s viscosity and improves the compactability of mixes [7]. The foaming WMA technologies have received a lot of attention due to its low costs, effectiveness in reducing mixing and production temperature and easy implementation. Many properties of mixes could be measured in the laboratory to predict the performance of an asphalt pavement or for the purpose of quality control and quality assurance. However, in the reality, asphalt mixes, either loose or compacted, could be tested days or even weeks after the production. Therefore, it comes to a question that when the properties should be measured and how the curing time would affect these properties, such as rutting and cracking resistance. Reinke et al. [8] studied the effect of curing time on the properties of Evotherm 3G WMA as compared to hot mix asphalt (HMA). They found that longer curing time help improve rutting resistance for both HMA and WMA mixes. The multiple stress creep recovery (MSCR) test performed on the recovered asphalt binder further

63

S. Wu, X. Li / Construction and Building Materials 145 (2017) 62–67

2. Materials, mix design and experiment 2.1. Materials Advera is a zeolite that consists of 20% water in the hydrocarbon compound. It is a product of Eurovia Services GmbH, Buttrop Germany. Previous study showed that it consists of hydrothermally crystallized synthetic zeolite which is sodium aluminum silicates [6]. By adding Advera in the heated asphalt, foaming occurs due to vaporization of water molecules which increases asphalt volume and reduces viscosity of binder [15]. Hossain et al. [6] found that the optimum dosage of Advera is 6% by the mass of the binder, which did not alter the base binder’s PG. Handayaniet al. [16] found that 1% zeolite reduced mixing and compaction temperature on polymer modified asphalt by 30 °C. The manufacturer recommends the dosage of 0.3–0.9% by the weight of mix in order to reduce the production temperature by 10–20 °C. In this study, Advera additive was added at the dosage of 0.3% by the weight of mix. The aggregate used was basalt provided by POE Asphalt Inc. The asphalt binder type was PG 58-28 provided by Western State Asphalt. 2.2. Mix design The mix design in this study was in accordance with Superpave mix design method [17]. The mix design kept the same for HMA and Advera mix, including aggregate gradation (Fig. 1), asphalt binder content, and aggregate type. Both mixes used 12.5-mm nominal maximum aggregate size (NMAS). Table 1 presents the volumetrics properties of HMA and Advera mixes, respectively.

100 90 80 70

% Passing

60 50 40 30 20

19

12.5

9.5

4.75

2.36

1.18

0

0.60

10 0.075 0.15 0.30

indicated that a longer curing time resulted in a lower nonrecoverable creep compliance, i.e., an improved rutting resistance. Buecheet et al. [9] studied the curing time and conditioning method on the properties of HMA and WMA mixes. They cured the specimens for up to 12 weeks at room temperature, with sealing the specimens in bag or exposing them to the air. In their study, it was found that conditioning method (sealing or not) did not result in a statistically significant difference in material properties. However, as curing time increased, the rutting resistance of watercontaining foaming WMA mix increased whereas no conclusion was reached for indirect tensile (IDT) strength or moisture susceptibility. The long-term aging effect on the WMA’s rutting and moisture resistance were evaluated by many researchers [2,10–12]. Mogawer et al. [2] found higher rutting resistance for HMA and Advera mix with increased aging time. Punith et al. [10] also found that long-term aging improved the moisture resistance of WMA. The addition of water-containing additive in the asphalt mix changes the rheological properties of binder and the material properties of asphalt mixes [2–4,13]. Al-Qadi et al. [14] concluded that a significantly longer curing time was needed before traffic open for WMA pavements. The literature review indicated that most researches have focused on the rutting and moisture resistance for the WMA as compared to HMA. There is a need to evaluate the effect of curing time on other properties, such as fatigue and thermal cracking. The storage condition and curing time further complicates the evolution of WMA. As such, the objective of this study was to evaluate the effect of curing time on the material properties of Advera mix, as compared to HMA control mix. Three curing times were included: two weeks (2 W), one month (1 M) and 2 months (2 M). The material properties evaluated in this study included stiffness, moisture damage potential, rutting susceptibility, and fatigue and thermal cracking resistance.

Sieve Size (mm) Raised to 0.45 Power Fig. 1. Aggregate gradation in this study.

Table 1 Mix design for HMA and Advera mixes. Volumetrics

HMA

Advera

Optimal AC, % % Gmm @ Ninitial % Gmm @ Ndesign VMA, % Designed air void, % VFA, % Dust/asphalt ratio Effective AC, % Gmm Gmb Gse

5.8 85.4 96.0 14.2 4.0 71.9 0.92 4.3 2.583 2.486 2.848

5.9 85.5 96.0 14.4 4.0 72.1 0.9 4.4 2.589 2.485 2.846

Note: AC – asphalt content, Gmm – maximum specific gravity, VMA – void in the mineral aggregate, VFA – void filled with asphalt, Gmb – bulk specific gravity, Gse – Effective specific gravity.

The mixing and compaction temperature of the Advera mix was 137 °C and 125 °C, respectively, which was 27 °C lower than the HMA production temperature, according to the manufacturer’s recommendation. Both HMA and Advera mixes showed similar volumetric properties.

2.3. Laboratory experiments The material properties of asphalt mixes were evaluated in terms of dynamic modulus, flow number, moisture damage, fatigue and thermal cracking resistance for both HMA and Advera mixes. The laboratory mixed laboratory compacted (LMLC) specimens were prepared at targeted air void using gyratory compactor following AASHTO T315 [18]. The specimens were placed in a sealed bag and stored in closet at controlled temperature (25 °C) and humidity (30%) without the exposure to light to minimize the effects of oxidization on the properties of mixes. The specimens were then tested after 2-week, 1-month and 2-month curing time.

2.3.1. Dynamic Modulus Dynamic Modulus (|E⁄|) test is used to characterize the stiffness of asphalt mixture. It represents asphalt mixture stiffness in response to the application of haversine compressive load over different loading rates and temperatures. It is also a material property input in the Mechanistic-empirical Pavement Design Guide (MEPDG) design [19], to predict rutting, fatigue cracking and thermal cracking performance of asphalt pavement. Dynamic modulus is calculated as amplitude of cyclic peak-to-peak stress by cyclic recoverable strain in the linear visco-elastic range.

64

S. Wu, X. Li / Construction and Building Materials 145 (2017) 62–67

AASTHO TP 79 [20] test protocol was followed to conduct dynamic modulus test using Asphalt Mixture Performance Tester (AMPT). Specimens were compacted in the gyratory compactor to a height of 170 mm. The gyratory compacted samples were then cored and cut to obtain dynamic modulus test specimen of 150 mm in height and 100 mm in diameter. The cored samples had targeted air void level 7 ± 0.5%. The tests were performed at four different temperatures (5, 21, 37, and 54 °C) and six different frequencies (0.01, 0.5, 1, 5, 10, and 25 Hz). Three replicates were tested for each mix. 2.3.2. Flow number test Flow number test evaluates the high temperature rutting potential of asphalt concrete. In the flow number test, 0.1 s of haversine load is applied with 0.9 s of rest time. Flow number is defined as maximum numbers of cycle to have a minimum rate of axial deformation or the beginning of tertiary creep phase of specimen. AASTHO TP 79 test protocol [20] was followed to perform the flow number test, using AMPT device. Since the dynamic modulus test is a non-destructive test, the same specimen used in dynamic modulus test was further tested for the flow number test. The test temperature was 58 °C. The deviatoric stress level was 600 kPa without confining stress. Three replicates were tested for both HMA control and Advera mixes. 2.3.3. Moisture susceptibility test A major concern for WMA is susceptibility to moisture-induced damage [11,12]. A common practice for mix designer to evaluate the moisture susceptibility test is tensile strengthen ratio (TSR) test, following AASHTO T283 [21]. TSR is defined as the ratio of tensile strength of conditioned specimen to that of unconditioned specimen, as shown in Eq. (1).

TSR ¼

S2 S1

ð1Þ

where S1 = average tensile strength of the unconditioned specimens (kPa); S2 = average tensile strength of the conditioned specimens (kPa). The conditioned specimens were subjected to freeze and thaw cycles whereas unconditioned specimens were stored at room temperature. The test specimens were prepared by gyratory compactor to a height of 95 mm and a diameter of 150 mm. The air void level was maintained to 7 ± 0.5%. A total of six specimens were prepared. Three specimens were kept as unconditioned specimens and stored in room temperature. The other 3 specimens were first vacuum saturated to obtain degree of saturation between 70 and 80 percent. The vacuum saturated specimens were then kept inside the freezer at 18 ± 3 °C for 18 h. After 18 h, the samples were kept in the water bath at 60 °C for 24 h. All the conditioned and unconditioned specimens were then kept inside the water bath at the temperature of 25 °C for two hours prior to testing. The specimens were tested using IDT test to measure its load. The loading rate was 50 mm/min. Test specimens were loaded until the peak load reached, and the tensile strength was calculated using Eq. (2).

St ¼

2000P pDt

D = specimen diameter (mm); t = specimen thickness (mm). 2.3.4. IDT test (fatigue and thermal cracking) Fatigue and thermal cracking distresses are related to the fracture behavior of asphalt mixes. Previous studies have shown that IDT test can be used to characterize the fracture properties of asphalt mixes [22–25]. Fracture work density has been reported to correlate well with thermal cracking resistance. A higher fracture work density indicates a better thermal cracking resistance. Wu et al. [1] found that the fracture work density had a good correlation with transverse cracking (either thermal cracking or reflective cracking) in the field. Shen et al. [26] used fracture work density to characterize cracking resistance of HMA and WMA pavements based on 28 field projects across the United States. In this study, asphalt mix specimens were prepared with 38 mm in thickness and 150 mm in diameter. A Geotechnical Consulting Testing System (GCTS) was used to conduct the IDT test. The specimen is loaded diametrically by applying constant displacement loading and the specimen breaks along the vertical diameter by the generation of horizontal tensile strain. The fatigue failure of asphalt pavement occurs at intermediate temperature, whereas thermal cracking occurs at lower temperature. Therefore, two temperatures and two loading rates were selected in this study. At room temperature of 20 °C, the loading rate was 50.8 mm/min for fatigue cracking test. Due to viscoelastic property of asphalt, at low temperature of 10 °C, the asphalt mixtures tend to have high strength, using relatively lower loading rate can help break the specimen without exceeding the capacity of GCTS machine. In this study, 12.7 mm/min was used for IDT thermal cracking test. Fracture work was calculated based on IDT test results, as shown in Fig. 2. Fracture work is the area under load and vertical loading ram displacement curve until load reaches zero. Fracture work density is the fracture work divided by the volume of tested specimen. Three replicates were tested for both IDT fatigue and thermal cracking test. 3. Test results and discussions 3.1. Dynamic modulus The dynamic modulus values at different temperatures and loading frequencies can be converted into master curves using Eqs. (3)–(5).

logðjE jÞ ¼ a þ

b 1 þ expcþdðlog tr Þ

ð2Þ

where St = tensile strength (kPa); P = maximum load (N);

Fig. 2. Load displacement curve: maximum load and fracture work.

ð3Þ

65

S. Wu, X. Li / Construction and Building Materials 145 (2017) 62–67

t aðTÞ

HMA

ð4Þ

logðt r Þ ¼ logðtÞ  logðaðTÞÞ

ð5Þ

where a, b, c, d = fitting parameters; tr = reference temperature; a(T) = shift factor as a function of temperature; T = temperature of interest. The dynamic modulus master curves at 21 °C reference temperature in terms of three curing times for HMA and Advera mixes are shown in Fig. 3a and b, respectively. The coefficient of variation of dynamic modulus value is less than 8%. It is observed that the master curves for HMA at three curing times (2 weeks, 1 month, and 2 months) overlap. However, for the Advera mix, the modulus at lower end (low frequency) after 1-month curing time is slightly higher than that after 2-week curing time, and it is more significant when comparing that after 2 weeks with after 2 months. As the curing time increases, the dynamic modulus (i.e. stiffness) of Advera mix increases. This is because the foam decays over time and the encapsulated air could escape and alter the stiffness of Advera mixes. 3.2. Flow number Fig. 4 presents the flow number test results of Advera and HMA mixes. The flow number of Advera mix increases with an increased curing time whereas no trend is seen for HMA mix. This indicates that as the Advera mix cures, the rutting resistance increases. This finding agrees with findings regarding Foaming WMA mix by other researchers [11–12,14].

100000

Flow Number

tr ¼

100 90 80 70 60 50 40 30 20 10 0

Advera 76

78

76 57

54

2 weeks

72

1 Month

2 Months

Curing Time Fig. 4. Flow number test results.

A t-test statistical analysis was performed on the comparison among 2 weeks, 1 month, and 2 months to evaluate the significance of the effect of curing time on flow number, as shown in Table 2.The significance level of 0.05 is used in this study. This significance level was also used to conduct statistical analysis on laboratory prepared specimens for HMA and WMA [26,27]. If p-value is less than 0.05, then there is a significant difference between two mixes. It is seen that the curing time has no significant effect on HMA’s flow number, with all p-values more than 0.05. For the Advera mix, no significant difference is observed between 2 weeks and 1 month. But there is significant difference between 1 month and 2 month, as well as 2 weeks and 2 months. Table 2 also presents the statistical comparison between HMA and Advera mix. Significant difference is found in flow number after 2-week curing and after 1-month curing, but not for after 2-month curing. As shown in Fig. 4, the HMA mix shows higher flow number than the Advera mix, and the Advera mix catches up with HMA after 2-month curing. It indicates that after 2month curing, the rutting property of WMA increased to a comparable level with that of HMA.

E*, MPa

10000

3.3. Moisture resistance

1000 HMA 2 Weeks HMA 1 Month HMA 2 Months

100 10 1 0.0001

0.01

1

100

10000

Reduced Frequency, Hz

(a) HMA 100000

E*, MPa

10000

The moisture resistance of asphalt mix is characterized by TSR. Typically, a minimum TSR of 0.8 ensures a mix to have sufficient moisture resistance. Fig. 5 presents TSR values of HMA and Advera mixes. As shown, there is no moisture susceptibility issue for HMA mix, with TSR more than 0.8. The curing time has no clear trend for the HMA mix. For the Advera mix, the TSR both after 2-week curing and 1-month curing cannot meet the 0.8 requirement. However, the TSR value for the Advera mix after 2-month curing increased to a comparable level with HMA. It reveals that the moisture resistance for the Advera mix improves with increased curing time. There is a need to develop an appropriate test procedure to perform TSR moisture resistance test for the Advera mix, by considering curing effect.

1000 100

Advera 2 Weeks Advera 1 Month Advera 2 Months

10 1 0.0001

0.01

1

100

10000

Reduced Frequency, Hz

(b) Advera Fig. 3. Dynamic modulus master curve at reference temperature of 21 °C.

3.4. IDT test at 20 °C Fracture work density is a combination of strength and deformation property of mix, and it is used to characterize the fatigue resistance. A high fracture work density value from IDT test at 20 °C indicates a mix having a better fatigue cracking resistance. Fig. 6 shows the fracture work density for HMA and Advera mix with curing time. As shown, the fracture work density of Advera mix increases with increased curing time, while that of HMA is similar regardless of three curing times.

66

S. Wu, X. Li / Construction and Building Materials 145 (2017) 62–67

Table 2 Flow number statistical analysis results. Comparison between different curing times

HMA p-value

Advera p-value

Comparison between HMA and Advera

p-Value

Between 2W and 1M Between 1M and 2M Between 2W and 2M

0.92 0.88 0.84

0.78 0.02 0.03

2W 1M 2M

0.09 0.02 0.31

Note: 2W – 2 weeks, 1M – 1 month, 2M – 2 months.

TSR

Advera

0.96

1 0.8

fracture work density than HMA mix. The curing time has a pronounced effect on the fatigue cracking resistance of Advera mix.

HMA

1.2

0.82 0.84

0.8

0.6

3.5. IDT test at 10 °C

0.64

0.59

The thermal cracking resistance is characterized by IDT test at 10 °C. As shown in Fig. 7, no clear effects of curing time are observed on both HMA and Advera mixes in terms of IDT strength. Table 4 further shows the statistical analysis results for the significance of curing time on mix thermal behavior. Based on significance level of 0.05, curing time has no significant effect on the thermal cracking resistance of HMA mix in terms of IDT strength. For the Advera mix, no significant difference is observed between 2-week curing and 1-month curing, and between 2-week curing and 2-month curing. But there exists a significant difference between 1-month curing and 2-month curing, and the IDT strength at 2-month curing is 11.5% higher than that at 1-month curing. It is interestingly seen in Fig. 7 that the Advera mix has higher IDT strength than the HMA mix after 2-week curing and after 2month curing. The statistical analysis in Table 4 also indicates this. This is because possible water in the Advera mix filled in the air void of mix becomes ice at low temperature, and contributes for IDT strength of Advera mix. After 1-month curing, the IDT strength difference between HMA and Advera mix is insignificant, although the Advera mix shows slightly higher IDT strength than the HMA mix.

0.4 0.2 0

2 Weeks

1 Month

2 Months

Curing Time Fig. 5. TSR test results.

HMA

Fracture Work Density, kPa

80

Advera

70 55.8

60 50

46.6

42.8 38.3

40

43.5

39.0

30 20 10 0

2 Weeks

1 Month

HMA

2 Months 8

Curing Time

Advera

7

IDT Strength, MPa

Fig. 6. IDT test results at 20 °C: fracture work density.

Statistical analysis result for fracture work density at 20 °C is presented in Table 3. For the HMA mix, there is no significant difference among any of the three curing times used in this study. For the Advera mix, for each curing period comparison, there is significant difference. With curing time increases, the fatigue cracking resistance is improved. It is also seen that there is a significant difference between HMA and Advera mix at each curing time level. It is interesting to see that after 2-week curing time, HMA mix has higher fracture work density than the Advera mix, but after 1month and 2-month curing, the Advera mix has increased to higher

6

5.8 5.0

5.4

5.5

5.7

6.1

5 4 3 2 1 -

2 Weeks

1 Month

2 Months

Curing Time Fig. 7. IDT test results at 10 °C: IDT strength.

Table 3 IDT test at 20 °C results statistical analysis results. Fracture work density comparison between different curing times

HMA p-value

Advera p-value

Fracture work density comparison between HMA and Advera

p-Value

Between 2W and 1M Between 1M and 2M Between 2W and 2M

0.06 0.08 0.75

0.03 0.02 0.01

2W 1M 2M

0.15 0.005 0.01

67

S. Wu, X. Li / Construction and Building Materials 145 (2017) 62–67 Table 4 IDT test at 10 °C results statistical analysis results. IDT strength comparison between different curing times

HMA p-value

Advera p-value

IDT strength comparison between HMA and Advera

p-Value

Between 2W and 1M Between 1M and 2M Between 2W and 2M

0.42 0.57 0.58

0.23 0.04 0.18

2W 1M 2M

0.07 0.77 0.07

4. Conclusions With rapid awareness in using green technology in asphalt pavement, WMA is widely used in recent years. Before its wide implementation, it is of importance to understand how to effectively evaluate WMA’s performance, especially for Foaming WMA that the entrapped water is of the concern. This study was conducted to quantify the effect of curing time (2 weeks, 1 month, and 2 months) on Advera foaming WMA and its control HMA. Based on the test results, the following findings are summarized: 1) The dynamic modulus master curves indicate that the stiffness of the Advera mix increases with the increase of curing time whereas that of HMA mix does not change over time. 2) The rutting resistance of the Advera mix increases as the curing time increases whereas curing time does not have significant effect on HMA’s rutting resistance. The HMA mix shows higher flow number than the Advera mix, however, the difference becomes smaller at 2-month curing. 3) The moisture damage resistance of the Advera mix increases with the increase of the curing time. The Advera mix has a moisture susceptibility issue at early curing time, but the moisture resistance improves after 2-month curing time, and becomes comparable as that of HMA mix. 4) The curing time has a pronounced effect on the fatigue resistance of Advera mix, based on fracture work density. However, fatigue resistance of HMA control mix does not change with curing time. 5) Curing time has no significant effect on the HMA mix in terms of IDT strength at low temperature. No clear trend is observed regarding the effect of curing time on the thermal cracking resistance of Advera mix. The improved performance for the Advera mix with curing time is due to the loss of moisture trapped in the mix. Further studies are needed to evaluate more foaming WMA technologies and materials, as well as other curing conditions, such as storage temperature, humidity, and lightness.

References [1] S. Wu, H. Wen, W. Zhang, S. Shen, A. Faheem, L.N. Mohammad, Long-term field transverse cracking performance of warm-mix asphalt pavement and its significant material property, J. Transp. Res. Board 2576 (2016) 109–120. [2] W.S. Mogawer, A.J. Austerman, H.U. Bahia, Evaluating the effect of warm-mix asphalt technologies on moisture characteristics of asphalt binders and mixtures, J. Transp. Res. Board 2209 (2011) 52–66. [3] K.J. Jenkins, M.F.C. van de Ven, A.N. Mbarage, S.P. van der Walt, J. van den Heever, Performance of evaluation of WMA plant and field trial mixes, Mater. Struct. 47 (2014) 1301–1311. [4] M.R.W. Hasan, S.W. Goh, Z. You, Comparative study on the properties of WMA mixture using foamed admixture and free water system, Constr. Build. Mater. 48 (2013) 45–50. [5] S. Wu, H. Wen, W. Zhang, S. Shen, L.N. Mohammad, A. Faheem, B. Muhunthan, Field performance of top-down fatigue cracking for warm mix asphalt pavements, Int. J. Pavement Eng. (2016), http://dx.doi.org/10.1080/ 10298436.2016.1248204.

[6] Z. Hossain, M. Zaman, E.A. O’Rear, D.H. Chen, Effectiveness of water-bearing and anti-stripping additives in warm mix asphalt technology, Int. J. Pavement Eng. 13 (5) (2012) 424–432. [7] J. Wielinski, A. Hand, D.M. Rausch, Laboratory and field evaluations of foamed warm-mix asphalt projects, J. Transp. Res. Board 2126 (2009) 125–131. [8] G. Reinek, S. Veglahn, D. Herlitzka, S. Engber, D. Tranberg, Update on study of impact of loose mix aging time and temperature on the mechanistic performance of hot and warm bituminous mixture, Warm Mix Technical Working Group Meeting, Seattle, WA, 2009. http://www.warmmixasphalt. org/submissions/dec2009/Tuesa.m/04_Reinke_ PresentationforWarmMixTWGDec2009.pdf. [9] N. Bueche. Evaluation of WMA key performance with regard to curing time and conditioning method, 2nd International Warm-Mix Conference, St-Louis, Missouri, USA, 2011. http://www.asphaltpavement.org/big_files/11mwmx/ Papers/WM15_Bueche.pdf. [10] V.S. Punith, F. Xiao, B. Putman, S.N. Amirkhanian, Effects of long-term aging on moisture sensitivity of foamed WMA mixtures containing moist aggregates, Mater. Struct. 45 (2012) 251–264. [11] H. Malladi, D. Ayyala, A.A. Tayebali, N.P. Khosla, Laboratory evaluation of warm-mix asphalt mixtures for moisture and rutting susceptibility, J. Mater. Civ. Eng. 27 (5) (2015), http://dx.doi.org/10.1061/(ASCE)MT.19435533.0001107. [12] M.R.M. Hasan, Z. You, D. Porter, S.W. Goh, Laboratory moisture susceptibility evaluation of WMA under possible field conditions, Constr. Build. Mater. 101 (2015) 57–64. [13] P.E. Sebaaly, E.Y. Hajj, M. Piratheepan, Evaluation of selected warm mix asphalt technologies, Road Mater. Pavement Des. 16 (S1) (2015) 475–486. [14] I.L. Al-Qadi, H. Wang, J. Baek, Z. Leng, M. Doyen, S. Gillen, Effects of curing time and reheating on performance of warm stone-matrix asphalt, J. Mater. Civ. Eng. 24 (11) (2012) 1422–1428. [15] M.H. Yin, B. Lai, Viscoelastic characterization of zeolite modified asphalt binder considering phase transformation and air void interaction, Road Mater. Pavement Des. 13 (2012) 279–299. [16] A.T. Handayani, B.H. Setiaji, S. Prabandiyani, The use of natural zeolite as an additives in warm mix asphalt with polymer modified asphalt binder, Int. J. Eng. Res. Africa 15 (2015) 35–46. [17] American Association of State Highways and Transportation Officials AASHTO R35 (2015) Standard practice for Superpave volumetric design for asphalt mixtures. AASHTO Designation: R35-15. [18] American Association of State Highways and Transportation Officials AASHTO T312 (2015) Standard method for preparing and determining the density of asphalt mixture specimens by means of Superpave gyratory compactor. AASHTO Designation: T312-15. [19] American Association of State Highways and Transportation Officials AASHTO (2008) Mechanistic-Empirical Pavement Design Guide, Interim Edition: A Manual of Practice. [20] American Association of State Highways and Transportation Officials AASHTO TP79 (2015) Standard method of test for determining the dynamic modulus and flow number for asphalt mixtures using the asphalt mixture performance tester (AMPT). AASHTO Designation: TP79-15. [21] American Association of State Highways and Transportation Officials AASHTO T283-14 (2014) Standard method of test for resistance of compacted asphalt mixtures to moisture-induced damage. AASHTO Designation: T283-14. [22] S. Wu, K. Zhang, H. Wen, J. DeVol, K. Kelsey, Performance evaluation of hot mix asphalt containing recycled asphalt shingles in Washington State, J. Mater. Civ. Eng. 29 (1) (2016), http://dx.doi.org/10.1061/(ASCE)MT.1943-5533.0001357. [23] S. Wu, B. Muhunthan, H. Wen, Investigation of effectiveness of prediction of fatigue life for hot mix asphalt blended with recycled concrete aggregate using monotonic fracture testing, Constr. Build. Mater. 131 (2017) 50–56. [24] S. Wu, H. Wen, S. Chaney, K. Littleton, S. Muench, Evaluation of long-term performance of stone matrix asphalt in Washington State, J. Perform. Constr. Facil. (2016), http://dx.doi.org/10.1061/(ASCE) CF.1943-5509.0000939. [25] P.K. Das, Y. Tasdemir, B. Birgisson, Low temperature cracking performance of WMA with the use of the superpave indirect tensile test, Int. J. Constr. Build. Mater. 30 (2012) 643–649. [26] S. Shen, S. Wu, W. Zhang, H. Wen, A. Bahadori, L.N. Mohammad, B. Muhunthan, Performance of WMA technologies: stage II – long-term field performance, draft final report for NCHRP, 2017. [27] N. Bower, H. Wen, S. Wu, K. Willoughby, J. Weston, L. DeVol, Evaluation of the performance of warm mix asphalt in Washington State, Int. J. Pavement Eng. 17 (5) (2016) 423–434.