- Email: [email protected]
Effect of liquid ASAs on the rheological properties of crumb rubber modified asphalt
Construction and Building Materials 194 (2019) 238–246
Contents lists available at ScienceDirect
Construction and Building Materials journal homepage: www.elsevier.com/locate/conbuildmat
Effect of liquid ASAs on the rheological properties of crumb rubber modified asphalt Juncheng Tang a, Chongzheng Zhu a, Henglong Zhang a,⇑, Guoqing Xu a, Feipeng Xiao b, Serji Amirkhanian c a Key Laboratory for Green & Advanced Civil Engineering Materials and Application Technology of Hunan Province, College of Civil Engineering, Hunan University, Changsha 410082, China b Key Laboratory of Road and Traffic Engineering of Ministry of Education, Tongji University, Shanghai 201804, China c Department of Civil, Construction, and Environmental Engineering, University of Alabama, Tuscaloosa 35487, USA
h i g h l i g h t s
g r a p h i c a l a b s t r a c t
Effect of liquid ASAs on the
rheological properties of CRMA was investigated. ASAs with 0.25–0.75% dosages can improve the high temperature stability of CRMA. ASAs weaken the low temperature performance of CRMA to some extent. FTIR result indicates that the chemical reaction between amine in ASA and anhydride in CRMA can happen.
a r t i c l e
i n f o
Article history: Received 20 May 2018 Received in revised form 17 October 2018 Accepted 2 November 2018 Available online 10 November 2018 Keywords: Crumb rubber modified asphalt Liquid anti-stripping agents Rheological properties Fourier transform infrared spectroscopy
⇑ Corresponding author. E-mail address: [email protected] (H. Zhang). https://doi.org/10.1016/j.conbuildmat.2018.11.028 0950-0618/Ó 2018 Elsevier Ltd. All rights reserved.
a b s t r a c t Effect of three liquid anti-stripping agents (ASAs) (M5000, M1 and LOF-6500) on the rheological properties of crumb rubber modified asphalt (CRMA) was investigated. ASAs with three dosages (0.25%, 0.50%, and 0.75%) were interfused in CRMA using melt blending method. All binders were aged employing rolling thin film oven (RTFO) and pressure aging vessel (PAV). Fourier transform infrared spectroscopy (FTIR) was employed to characterize chemical functional groups of ASAs and CRMA. The high temperature rheological properties were evaluated by rotational viscosity, G*, d, G*/sin d, failure temperature, Jnr and R, while the low temperature rheological properties were assessed by S and m-value. FTIR result indicates that the chemical reaction between amine in ASA and anhydride in CRMA can happen, and usually form organogels which have exceptional thermal and mechanical stability compared with the amine substances and anhydrides. Rheological tests results show that, with adding various ASAs, the rotational viscosity, G*, G*/sin d, failure temperature, R and S are enhanced, while the d and m-value are reduced. It suggests that ASAs improve the high temperature stability of CRMA whereas weaken the low temperature performance of CRMA. Amplitude sweep test results suggest that adding various ASAs does not change the linear viscoelasticity of CRMA before aging when the shear strain range is from 0.01 to 0.1. However, after RTFO, adding M1 and LOF-6500 (aside from 0.75% dosage) greatly reduces the linear viscoelastic range of CRMA. Performance grade (PG) analysis illustrates that M5000 and M1 (except for 0.50% dosage) have no influence on the PG of CRMA, while LOF-6500 decreases one low temperature grade of CRMA. Ó 2018 Elsevier Ltd. All rights reserved.
J. Tang et al. / Construction and Building Materials 194 (2019) 238–246
1. Introduction
2. Experimental section
Asphalt pavement has been the major type of pavement due to its excellent performance. However, with the increase of the traffic and heavy vehicle and the damaging from external environmental factors, virgin asphalt pavement is difficult to fulfill the demand of pavement performance and durability. Therefore, some modifiers are used to improve performance of virgin asphalt [1–3]. Polymer modifiers (e.g. styrene-butadiene-styrene copolymer and styrenebutadiene rubber) as a type of common modifier could effectively enhance high and low temperature performances and anti-aging ability of virgin asphalt [4,5]. Besides, crumb rubber (CR) is another type of significant modifier. Many research have demonstrated that CR also could evidently improve high and low temperature, anti-fatigue and anti-aging performances of virgin asphalt [6–8]. Moreover, compared with expensive polymer modifiers, using CR is more economical, as well as more environmentally friendly due to waste rubber recycled. However, similar to virgin asphalt, moisture damage for crumb rubber modified asphalt (CRMA) is also a potential problem, even if some research have indicated that the moisture damage resistance of virgin asphalt could be enhanced limitedly by adding CR using wet process [9,10]. Worse still, for dry process or warm mix CRMA mixture, the moisture damage resistance could even be weakened [11–13]. Therefore, it is necessary to improve the moisture damage resistance of CRMA. Kim et al. [9] and Punith et al. [12] pointed out that hydrated lime could effectively improve the moisture sensitivity of CRMA. Arabani et al. [11] researched the effect of nanomaterial Zycosoil on property of dry process CRMA mixture, and found that Zycosoil could improve the moisture susceptibility. From the above, few research focus on the improvement in moisture damage resistance of CRMA. Some common liquid antistripping agents (ASAs) which have shown excellent antistripping performance for virgin asphalt or warm mix asphalt have not been applied to CRMA [14,15]. Hence, it is meaningful to do a systematic investigation on the performances of CRMA with liquid ASAs. This research aimed to study the effect of three liquid ASAs (M5000, M1 and LOF-6500) with three dosages (0.25%, 0.50%, and 0.75%) on the rheological properties of CRMA. Fourier transform infrared spectroscopy (FTIR) was employed to characterize chemical functional groups of ASAs and CRMA. The high temperature rheological properties were evaluated by rotational viscosity, G*, d, G*/sin d, failure temperature, Jnr and R, while the low temperature rheological properties were assessed by S and m-value.
2.1. Materials
239
In this study, Inman PG 64-22 from southeast area of USA was adopted as base asphalt. Three common liquid ASAs, namely MORLIE 5000 (M5000), EVOTHERM M1 (M1) and AD-hereÒLOF-65-00 (LOF-6500), were chosen. The essential properties of base asphalt and ASAs could be found in our published paper [16]. Crumb rubber was processed under ambient conditions, the size was 40 mesh (0.425 mm). 2.2. Preparation of crumb rubber modified asphalt containing ASA Melt blending method was utilized to prepare crumb rubber modified asphalt (CRMA) containing ASA. Firstly, base asphalt was heated until flow state. Then, 10% crumb rubber and different dosages (0%, 0.25%, 0.50% and 0.75%) ASA were introduced in base asphalt employing a mechanical mixer, and the operating conditions were 177 °C, 1000 rpm and 30 min. Besides, all prepared binders were aged employing rolling thin film oven (RTFO) according to ASTM D 2872 and pressure aging vessel (PAV) according to ASTM D 6521. 2.3. Experimental methods Chemical functional groups of ASAs and CRMA were characterized employing FTIR. Fourier infrared spectrometer from Thermo Nicolet Corp was used, and the operation of FTIR adopted transmission mode. The setting parameters such as wavenumber range, scanning number and resolution were 4000–400 cm1, 32 and 4 cm1, respectively. The rotational viscosity test (135 °C and 165 °C) was conducted employing Brookfield Viscometer in accordance with ASTM D 4402. Both temperature sweep mode and amplitude sweep mode were conducted employing dynamic shear rheometer according to ASTM D 7175. The variation of rheological properties such G*, d, G*/sin d and failure temperature as temperature or shear strain was measured. The high temperature deformation resistance of various CRMA binders after RTFO under repeated loads was assessed employing Multiple Stress Creep and Recovery (MSCR) test according to ASTM D 7405. The percent recovery (R) and non-recoverable creep compliance (Jnr) under 0.1 kPa and 3.2 kPa stress level were measured.
Fig. 1. Infrared spectrums of ASAs and CRMA (a) ASAs and (b) CRMA.
240
J. Tang et al. / Construction and Building Materials 194 (2019) 238–246
Fig. 2. Rotational viscosity of CRMA with various ASAs at 135 °C and 165 °C.
The low temperature performance of various CRMA binders after PAV was assessed employing bending beam rheometer (BBR) test according to ASTM D 6648. The creep stiffness (S) and creep rate (m-value) under 6 °C, 12 °C and 18 °C were measured. Three replicates for each type of binder were measured.
three ASAs are mainly made up of amine substances, many peaks belonging to the amine substances can be found in the infrared spectrums of ASAs. The peak at 3293 cm1 belongs to the stretching vibration of NAH, while both the two peaks at 1651 cm1 and 1557 cm1 are ascribed to the bending vibration of NAH [17,18]. The peak at 1128 cm1 is ascribed to the stretching vibration of aliphatic CAN [17]. In addition, as seen in Fig. 1(b), these weak peaks at 1825 cm1, 1743 cm1, 1710 cm1, 1700 cm1 and 1678 cm1 are ascribed to the stretching vibration of C@O. Furthermore, the peaks at 1825 cm1 and 1743 cm1 originate from anhydride, whereas the peaks at 1710 cm1, 1700 cm1 and 1678 cm1 result from aldehyde, carboxylic acid and ketone, respectively [19]. These substances containing C@O are mainly ascribed to the oxidation of asphalt [19–21], thus their amount in the virgin asphalt is quite little. Based on the above FTIR analysis for the chemical functional groups of ASAs and CRMA, a reaction between amine in ASAs and anhydride in asphalt binder can happen during the mixing process of ASAs and asphalt binder (the specification from ASAs manufacturer also stated that these ASAs are incompatible with strong oxidizing agents, halides, anhydride, etc). The reaction equation is shown below. The reaction products usually are organogels, which can show exceptional thermal and mechanical stability in comparison with the amine substances or anhydrides [22,23].
3. Results and discussion
ð1Þ
3.1. FTIR analysis The infrared spectrums of ASAs and CRMA are displayed in Fig. 1(a) and (b), separately. As the Fig. 1(a) shows, because the
Fig. 3. G* and d values of CRMA with various ASAs before aging (a) M5000, (b) M1 and (c) LOF-6500.
J. Tang et al. / Construction and Building Materials 194 (2019) 238–246
241
Fig. 4. G* and d values of CRMA with various ASAs after RTFO (a) M5000, (b) M1 and (c) LOF-6500.
3.2. Rotational viscosity Influence of different ASAs with different dosages on rotational viscosity at 135 °C and 165 °C of CRMA is displayed in Fig. 2. As the Fig. 2 shows, regardless of the temperatures, as the dosages increase from 0.25% to 0.75%, the viscosity of CRMA with M5000 or M1 increases initially and decreases afterwards, while that of CRMA with LOF-6500 keeps increasing tendency. Furthermore, the CRMA with 0.50% M5000 has the highest viscosity, the increments at 135 °C and at 165 °C are 44.3% and 43.8% of control sample, respectively. The increase in viscosity is ascribed to the organogels formed by mixing the amines in ASAs with the anhydrides in asphalt binder. However, as the dosage of ASA increases, the anhydrides (the amount is quite little) in CRMA are exhausted, the softening effect of ASAs for CRMA (the viscosity of CRMA is much higher than that of three ASAs) becomes more and more evident. Consequently, the viscosity of CRMA starts decreasing when the dosage of ASA exceeds some certain dosage. 3.3. Complex modulus and phase angle The G* and d of CRMA with various ASAs before aging are displayed in Fig. 3. As seen in Fig. 3(a) and (b), with the dosage of M5000 or M1 increasing, the G* firstly increases and then decreases. The CRMA with 0.50% M5000 or 0.50% M1 shows the highest G*. These results are consistent with the rotational viscosity result. As seen in Fig. 3(c), although there is no similar regularity to M5000 or M1 by analyzing the G* of CRMA with three dosages LOF-6500, the CRMA with LOF-6500 shows the higher G*
than the CRMA without LOF-6500. Furthermore, the enhancement in G* for M1 is more obvious compared with M5000 and LOF-6500. Besides, as seen in Fig. 3, regardless of the ASA types, the addition of ASA with different dosages can decrease the d of CRMA, indicating that the elastic behavior is enhanced when the dosages are limited to the 0.75% range. For M5000 or M1, the CRMA with 0.25% has the lowest d, whereas the CRMA with 0.50% LOF-6500 shows the lowest d. Above results that both the enhancement in G* and the reduction in d are also caused by the organogels formed after adding ASA in CRMA. Fig. 4 shows the G* and d of CRMA with various ASAs after RTFO. As seen in Fig. 4, except for 0.75% M1 and 0.25% LOF-6500, other ASAs increase the G* of CRMA after RTFO. Moreover, regardless of the ASA types, the CRMA with 0.50% has the highest G* (the difference for the CRMA with M1 between 0.25% and 0.50% is quite little). Besides, for M5000 and M1, various dosages of ASA can reduce the d of CRMA after RTFO. However, as the dosage increases, the change in G* and d of CRMAs with three ASAs does not have obvious regularity. These irregular results may be caused by various factors. Four possible factors as follows: 1) After RTFO, some new anhydrides in CRMA are produced, which in turn restarts the reaction (1); 2) Some amines in ASAs belong to active antioxidants, which can retard the hardening of CRMA during RTFO [24,25]; 3) The amine substances in three ASAs are different. The main ingredients of M5000 are alkylamines, alkanol amines and alkylene amines, while the main ingredient of M1 and LOF-6500 are fatty amines derivatives and amidoamines respectively [16]; 4) ASAs have softening effect on CRMA when the amount of ASAs exceeds a certain dosage.
242
J. Tang et al. / Construction and Building Materials 194 (2019) 238–246
Fig. 5. G*/sin d of CRMA with various ASAs at various temperatures before and after RTFO (a) M5000, (b) M1 and (c) LOF-6500.
Fig. 6. Failure temperature of CRMA with various ASAs (a) before aging and (b) after RTFO.
3.4. Rutting resistance factor Rutting resistance factor (G*/sin d) of CRMA with various ASAs at various temperatures before and after RTFO is displayed in Fig. 5. As Fig. 5(a)–(c) show, before aging, interfusing ASAs increases the G*/sin d of CRMA irrespective of the ASA types and dosages. Furthermore, the CRMA with M1 shows the higher G*/sin d than the CRMA with M5000 or LOF-6500. The result illustrates that the interfusion of ASAs can enhance the rutting resistance of CRMA, which is also attributed to the formed organogels after adding ASAs in CRMA.
Additionally, as seen in Fig. 5, after RTFO, the G*/sin d of various CRMA binders obviously increases compared with unaged CRMA binders. This is because RTFO aging leads to the volatilization of light constituents and the conversion of aromatics and resins to asphaltenes in asphalt binder [26]. Except for 0.75% M1 and 0.25% LOF-6500, other ASAs enhance the G*/sin d of CRMA after RTFO. Furthermore, for M5000 or LOF-6500, the CRMA with 0.50% has the highest G*/sin d, while the CRMA with 0.25% M1 shows the highest G*/sin d. However, there is no obvious regularity that the variation in G*/sin d of CRMA with ASAs as the dosage increases.
J. Tang et al. / Construction and Building Materials 194 (2019) 238–246
243
Fig. 7. Jnr and R for CRMA with various ASAs at 76 °C under 0.1 kPa and 3.2 kPa (a) Jnr-0.1, (b) R-0.1, (c) Jnr-3.2 and (d) R-3.2.
3.5. Failure temperature The failure temperature (before aging, G*/sin d = 1.0 kPa; after RTFO, G*/sin d = 2.2 kPa) is usually utilized to confirm the high temperature performance grade of asphalt binder. As Fig. 6(a) shows, before aging, the addition of ASAs can increase the failure temperature of CRMA. Moreover, compared with various dosages for each type of ASA, the CRMAs with 0.50% M5000, 0.50% M1 or 0.75% LOF-6500 show the highest failure temperature, the increments relative to control sample are 1.3 °C, 2.3 °C and 1.3 °C respectively. Additionally, as Fig. 6(b) shows, after RTFO, except for 0.75% M1 and 0.25% LOF-6500, other ASAs can increase the failure temperature of CRMA after RTFO. The CRMAs with 0.50% M5000, 0.25% M1 or 0.50% LOF-6500 show the highest failure temperature, the increments relative to control sample are 4.1 °C, 4.5 °C and 2.8 °C respectively. 3.6. MSCR test The Jnr and R for CRMA with various ASAs after RTFO at 76 °C under 0.1 kPa and 3.2 kPa are shown in Fig. 7. As seen in Fig. 7(a) and (c), regardless of the stress levels, except for 0.75% M1 and 0.25% LOF-6500, other ASAs can decrease the Jnr of CRMA after RTFO at 76 °C. It suggests that the interfusion of ASAs can enhance the deformation resistance of CRMA at high temperature. Moreover, the CRMAs with 0.50% M5000, 0.25% M1 and 0.50% LOF6500 show the most obvious improvement. Besides, as seen in Fig. 7(b) and (d), irrespective of the stress levels, the CRMAs with various ASAs (except for 0.75% M1 and 0.25% LOF-6500) show
the higher R than control sample. This result suggests that the addition of ASAs enhances the elastic response of CRMA. Above results indicate that three ASA with various dosages can improve the rutting resistance of CRMA under repeated loads, which is in accordance with the results from G*/sin d. 3.7. Amplitude sweep test A linear region of asphalt binder may be defined at small strains where the G* is relatively independent of shear strain. The region will change with the magnitude of G*. According to AASHTO T 315-12, the linear region is defined as the range in strains where the G* is 95% or more of the zero-strain value. Fig. 8 shows, before aging, the G* and d values of CRMA with various ASAs during various strains at 76 °C. Based on the G* data, it can be determined that the shear strain range from 0.01 to 0.1 is the linear region of all binders before aging. It means that after adding various ASAs the G* of CRMA is still relatively independent of shear strain when its range is from 0.01 to 0.1. Additionally, as Fig. 8 shows, the interfusion of various ASAs reduces the d of CRMA. It indicates that the CRMAs with ASA have the more elastic components than control sample. Consequently, the deformation resistance of the CRMAs with ASA at high temperature is better. This result is in accordance with the results from temperature sweep test. Fig. 9 shows, after RTFO, the G* and d values of CRMA with various ASAs during various strains at 76 °C. As seen in Fig. 9(a), the G* data shows that the strain ranging from 0.01 to 0.1 is linear viscoelastic range of the CRMA with various dosages M5000 after RTFO. Moreover, the CRMA with M5000 shows the lower d
244
J. Tang et al. / Construction and Building Materials 194 (2019) 238–246
Fig. 8. G* and d values of CRMA with various ASAs before aging during various strains at 76 °C (a) M5000, (b) M1 and (c) LOF-6500.
compared with control sample. However, as seen in Fig. 9(b), the G* data implies that introducing M1 (especially for 0.75% dosage) greatly narrows the linear viscoelastic range of CRMA after RTFO. Additionally, as seen in Fig. 9(c), the G* data also indicates that adding LOF-6500 (aside from 0.75% LOF-6500) significantly reduces the linear viscoelastic range of CRMA after RTFO. Above results suggest that the addition of M1 or LOF-6500 increases the sensibility of CRMA after RTFO to shear strain, while the M5000 has no influence on that of CRMA after RTFO to shear strain.
PG 76-22 with control sample. However, for M1, the CRMA with 0.25% or 0.75% dosage has the PG 76-22, while the CRMA with 0.50% dosage increases one high temperature grade and decreases one low temperature grade. Meanwhile, for LOF-6500, various dosages LOF-6500 do not change the high temperature grade, whereas they decrease one low temperature grade. Above results suggest that M5000 and M1 (except for 0.50% dosage) have no influence on the PG of CRMA, while LOF-6500 can decrease one low temperature grade of CRMA.
3.8. BBR test
4. Conclusions
BBR test is conducted to evaluate the low temperature performance of asphalt binders. Fig. 10 shows the S and m-value of CRMA with various ASAs after PAV at various temperatures. As seen in Fig. 10, irrespective of the ASA types and dosages, adding ASAs increases the S and decreases the m-value. This result illustrates that three ASAs can weaken the low temperature performance of CRMA after PAV, which may be attributed to the formed organogels. Compared with M5000 and M1, the enhancement in S and the reduction in m-value for the CRMA with LOF-6500 are more obvious. Furthermore, for M1 and LOF-6500, the CRMA with 0.50% dosage has the highest S and the lowest m-value, whereas the CRMA with 0.75% dosage M5000 has the highest S and the lowest m-value.
In this research, the influence of three liquid ASAs with different dosages on the rheological properties of CRMA was studied. The main results are as follows:
3.9. Performance grade Performance grade (PG) is critical indicator assessing the high and low temperature performance of asphalt binder. The PG of CRMA with various ASAs is displayed in Table 1. As illustrated in Table 1, the CRMAs with various dosages M5000 show the same
(1) Based on the FTIR analysis, many functional groups containing NAH exist in three ASAs, and a small number of aldehydes exist in CRMA. Thus the reaction between amine and anhydride can happen, and the products usually are organogels which can exhibit exceptional thermal and mechanical stability compared with amine substances or anhydrides. (2) After adding three ASAs with 0.25%–0.75% dosages, the rotational viscosity, G*, G*/sin d and failure temperature of CRMA before aging are enhanced, while the d is reduced. It implies that the high temperature stability of CRMA is enhanced. Moreover, the CRMAs with 0.50% M5000, 0.50% M1 and 0.75% LOF-6500 show the highest enhancement. (3) Three ASAs (except for 0.75% M1 and 0.25% LOF-6500) can enhance the G*, G*/sin d and failure temperature of CRMA after RTFO, whereas reduce the Jnr, demonstrating that the
J. Tang et al. / Construction and Building Materials 194 (2019) 238–246
Fig. 9. G* and d values of CRMA with various ASAs after RTFO during various strains at 76 °C (a) M5000, (b) M1 and (c) LOF-6500.
Fig. 10. S and m-value of CRMA with various ASAs after PAV at various temperatures (a) M5000, (b) M1 and (c) LOF-6500.
245
246
J. Tang et al. / Construction and Building Materials 194 (2019) 238–246
Table 1 PG of CRMA with various ASAs. CRMA types Control sample CRMA + M5000
Performance grade 0.25% 0.50% 0.75%
76–22 76–22 76–22 76–22
CRMA + M1
0.25% 0.50% 0.75%
76–22 82–16 76–22
CRMA + LOF-6500
0.25% 0.50% 0.75%
76–16 76–16 76–16
high temperature stability of CRMA after RTFO is also enhanced. Besides, the CRMAs with 0.50% M5000, 0.25% M1 and 0.50% LOF-6500 show the most obvious improvement. (4) According to the amplitude sweep test results, the introduction of three ASAs with 0.25%–0.75% dosages does not change the linear viscoelasticity of CRMA before aging when the shear strain range is from 0.01 to 0.1. However, after RTFO, M1 and LOF-6500 (aside from 0.75% dosage) significantly reduce the linear viscoelastic range of CRMA. (5) Adding three ASAs with 0.25%-0.75% dosages increases the S and reduces the m-value of CRMA after PAV, suggesting that the low temperature performance of CRMA is weakened. Furthermore, compared with M5000 and M1, LOF-6500 shows the more serious influence. PG analysis indicates that M5000 and M1 (except for 0.50% dosage) have no influence on the PG of CRMA, while LOF-6500 can decrease one low temperature grade of CRMA. Conflict of interest None. Acknowledgements This work was supported by the Hunan Provincial Natural Science Foundation of China (No. 2017JJ3015), the Transportation Science and Technology Development and Innovation Project of Hunan Province (No. 201705), the Science and Technology Planning Project of Changsha (Nos. kc1703038, kq1706018) and. The authors gratefully acknowledge their financial support. References [1] G. Airey, Rheological properties of styrene butadiene styrene polymer modified road bitumens, Fuel 82 (2003) 1709–1719.
[2] M. García-Morales, P. Partal, F.J. Navarro, C. Gallegos, Effect of waste polymer addition on the rheology of modified bitumen, Fuel 85 (2006) 936–943. [3] B.V. Kök, M. Yilmaz, M. Guler, Evaluation of high temperature performance of SBS+Gilsonite modified binder, Fuel 90 (2011) 3093–3099. [4] G. Polacco, S. Filippi, F. Merusi, G. Stastna, A review of the fundamentals of polymer-modified asphalts: asphalt/polymer interactions and principles of compatibility, Adv. Colloids Interface Sci. 224 (2015) 72–112. [5] Z.G. Feng, J.Y. Yu, The research for high-performance SBR compound modified asphalt, Constr. Build. Mater. 24 (2010) 410–418. [6] J. Shen, S. Amirkhanian, The influence of crumb rubber modifier (CRM) microstructures on the high temperature properties of CRM binders, Int. J. Pavement Eng. 6 (2007) 265–271. [7] S.K. Palit, K.S. Reddy, B.B. Pandey, Laboratory evaluation of crumb rubber modified asphalt mixes, J. Mater. Civ. Eng. 16 (2004) 45–53. [8] Q. Wang, S. Li, X. Wu, S. Wang, C. Ouyang, Weather aging resistance of different rubber modified asphalts, Constr. Build. Mater. 106 (2016) 443–448. [9] S. Kim, S.J. Lee, Y.B. Yun, K.W. Kim, The use of CRM-modified asphalt mixtures in Korea: evaluation of high and ambient temperature performance, Constr. Build. Mater. 67 (2014) 244–248. [10] B. Shirini, R. Imaninasab, Performance evaluation of rubberized and SBS modified porous asphalt mixtures, Constr. Build. Mater. 107 (2016) 165–171. [11] M. Arabani, S.A. Tahami, G.H. Hamedi, Performance evaluation of dry process crumb rubber-modified asphalt mixtures with nanomaterial, Road Mater. Pavement 19 (2018) 1241–1258. [12] V.S. Punith, F. Xiao, S.N. Amirkhanian, Effects of lime content on moisture susceptibility of rubberized stone matrix asphalt mixtures using warm mix additives in terms of statistical analysis, J. Mater. Civ. Eng. 24 (2012) 1431– 1440. [13] H. Yu, Z. Leng, Z. Dong, Z. Tan, F. Guo, J. Yan, Workability and mechanical property characterization of asphalt rubber mixtures modified with various warm mix asphalt additives, Constr. Build. Mater. 175 (2018) 392–401. [14] F. Xiao, S.N. Amirkhanian, Effects of liquid antistrip additives on rheology and moisture susceptibility of water bearing warm mixtures, Constr. Build. Mater. 24 (2010) 1649–1655. [15] D.W. Park, W.J. Seo, J. Kim, H.V. Vo, Evaluation of moisture susceptibility of asphalt mixture using liquid anti-stripping agents, Constr. Build. Mater. 144 (2017) 399–405. [16] C.Z. Zhu, G.Q. Xu, H.L. Zhang, F.P. Xiao, S. Amirkhanian, C.F. Wu, Influence of different anti-stripping agents on the rheological properties of asphalt binder at high temperature, Constr. Build. Mater. 164 (2018) 317–325. [17] G. Yang, W.S. Chang, D.T. Hallinan Jr., A convenient phase transfer protocol to functionalize gold nanoparticles with short alkylamine ligands, J. Colloids Interface Sci. 460 (2015) 164–172. [18] X. Yang, T. Mei, J. Yang, C. Zhang, M. Lv, X. Wang, Synthesis and characterization of alkylamine-functionalized graphene for polyolefin-based nanocomposites, Appl. Surf. Sci. 305 (2014) 725–731. [19] H. Yao, Q. Dai, Z. You, Fourier Transform Infrared Spectroscopy characterization of aging-related properties of original and nano-modified asphalt binders, Constr. Build. Mater. 101 (2015) 1078–1087. [20] D. Lesueur, The colloidal structure of bitumen: consequences on the rheology and on the mechanisms of bitumen modification, Adv. Colloids Interface Sci. 145 (2009) 42–82. [21] S. Wu, Z. Zhao, Y. Xiao, M. Yi, Z. Chen, M. Li, Evaluation of mechanical properties and aging index of 10-year field aged asphalt materials, Constr. Build. Mater. 155 (2017) 1158–1167. [22] S.C. Xu (Ed.), Organic Chemistry, Higher Education Press, Beijing, 2014, pp. 377–378 (in Chinese). [23] R.D. Mahapatra, J. Dey, Instant gels from mixtures of amines and anhydrides at room temperature, Colloids Surf. B 147 (2016) 422–433. [24] A. James, D. Stewart, The use of fatty amine derivatives to slow down the agehardening process in bitumen Rome, in: Proc. of International Symposium Chemistry of Bitumens, 1991, pp. 671–684. [25] I. Gawel, F. Czechowski, J. Kosno, An environmental friendly anti-ageing additive to bitumen, Constr. Build. Mater. 110 (2016) 42–47. [26] X. Lu, I. Ulf, Effect of ageing on bitumen chemistry and rheology, Constr. Build. Mater. 16 (2002) 15–22.
Contents lists available at ScienceDirect
Construction and Building Materials journal homepage: www.elsevier.com/locate/conbuildmat
Effect of liquid ASAs on the rheological properties of crumb rubber modified asphalt Juncheng Tang a, Chongzheng Zhu a, Henglong Zhang a,⇑, Guoqing Xu a, Feipeng Xiao b, Serji Amirkhanian c a Key Laboratory for Green & Advanced Civil Engineering Materials and Application Technology of Hunan Province, College of Civil Engineering, Hunan University, Changsha 410082, China b Key Laboratory of Road and Traffic Engineering of Ministry of Education, Tongji University, Shanghai 201804, China c Department of Civil, Construction, and Environmental Engineering, University of Alabama, Tuscaloosa 35487, USA
h i g h l i g h t s
g r a p h i c a l a b s t r a c t
Effect of liquid ASAs on the
rheological properties of CRMA was investigated. ASAs with 0.25–0.75% dosages can improve the high temperature stability of CRMA. ASAs weaken the low temperature performance of CRMA to some extent. FTIR result indicates that the chemical reaction between amine in ASA and anhydride in CRMA can happen.
a r t i c l e
i n f o
Article history: Received 20 May 2018 Received in revised form 17 October 2018 Accepted 2 November 2018 Available online 10 November 2018 Keywords: Crumb rubber modified asphalt Liquid anti-stripping agents Rheological properties Fourier transform infrared spectroscopy
⇑ Corresponding author. E-mail address: [email protected] (H. Zhang). https://doi.org/10.1016/j.conbuildmat.2018.11.028 0950-0618/Ó 2018 Elsevier Ltd. All rights reserved.
a b s t r a c t Effect of three liquid anti-stripping agents (ASAs) (M5000, M1 and LOF-6500) on the rheological properties of crumb rubber modified asphalt (CRMA) was investigated. ASAs with three dosages (0.25%, 0.50%, and 0.75%) were interfused in CRMA using melt blending method. All binders were aged employing rolling thin film oven (RTFO) and pressure aging vessel (PAV). Fourier transform infrared spectroscopy (FTIR) was employed to characterize chemical functional groups of ASAs and CRMA. The high temperature rheological properties were evaluated by rotational viscosity, G*, d, G*/sin d, failure temperature, Jnr and R, while the low temperature rheological properties were assessed by S and m-value. FTIR result indicates that the chemical reaction between amine in ASA and anhydride in CRMA can happen, and usually form organogels which have exceptional thermal and mechanical stability compared with the amine substances and anhydrides. Rheological tests results show that, with adding various ASAs, the rotational viscosity, G*, G*/sin d, failure temperature, R and S are enhanced, while the d and m-value are reduced. It suggests that ASAs improve the high temperature stability of CRMA whereas weaken the low temperature performance of CRMA. Amplitude sweep test results suggest that adding various ASAs does not change the linear viscoelasticity of CRMA before aging when the shear strain range is from 0.01 to 0.1. However, after RTFO, adding M1 and LOF-6500 (aside from 0.75% dosage) greatly reduces the linear viscoelastic range of CRMA. Performance grade (PG) analysis illustrates that M5000 and M1 (except for 0.50% dosage) have no influence on the PG of CRMA, while LOF-6500 decreases one low temperature grade of CRMA. Ó 2018 Elsevier Ltd. All rights reserved.
J. Tang et al. / Construction and Building Materials 194 (2019) 238–246
1. Introduction
2. Experimental section
Asphalt pavement has been the major type of pavement due to its excellent performance. However, with the increase of the traffic and heavy vehicle and the damaging from external environmental factors, virgin asphalt pavement is difficult to fulfill the demand of pavement performance and durability. Therefore, some modifiers are used to improve performance of virgin asphalt [1–3]. Polymer modifiers (e.g. styrene-butadiene-styrene copolymer and styrenebutadiene rubber) as a type of common modifier could effectively enhance high and low temperature performances and anti-aging ability of virgin asphalt [4,5]. Besides, crumb rubber (CR) is another type of significant modifier. Many research have demonstrated that CR also could evidently improve high and low temperature, anti-fatigue and anti-aging performances of virgin asphalt [6–8]. Moreover, compared with expensive polymer modifiers, using CR is more economical, as well as more environmentally friendly due to waste rubber recycled. However, similar to virgin asphalt, moisture damage for crumb rubber modified asphalt (CRMA) is also a potential problem, even if some research have indicated that the moisture damage resistance of virgin asphalt could be enhanced limitedly by adding CR using wet process [9,10]. Worse still, for dry process or warm mix CRMA mixture, the moisture damage resistance could even be weakened [11–13]. Therefore, it is necessary to improve the moisture damage resistance of CRMA. Kim et al. [9] and Punith et al. [12] pointed out that hydrated lime could effectively improve the moisture sensitivity of CRMA. Arabani et al. [11] researched the effect of nanomaterial Zycosoil on property of dry process CRMA mixture, and found that Zycosoil could improve the moisture susceptibility. From the above, few research focus on the improvement in moisture damage resistance of CRMA. Some common liquid antistripping agents (ASAs) which have shown excellent antistripping performance for virgin asphalt or warm mix asphalt have not been applied to CRMA [14,15]. Hence, it is meaningful to do a systematic investigation on the performances of CRMA with liquid ASAs. This research aimed to study the effect of three liquid ASAs (M5000, M1 and LOF-6500) with three dosages (0.25%, 0.50%, and 0.75%) on the rheological properties of CRMA. Fourier transform infrared spectroscopy (FTIR) was employed to characterize chemical functional groups of ASAs and CRMA. The high temperature rheological properties were evaluated by rotational viscosity, G*, d, G*/sin d, failure temperature, Jnr and R, while the low temperature rheological properties were assessed by S and m-value.
2.1. Materials
239
In this study, Inman PG 64-22 from southeast area of USA was adopted as base asphalt. Three common liquid ASAs, namely MORLIE 5000 (M5000), EVOTHERM M1 (M1) and AD-hereÒLOF-65-00 (LOF-6500), were chosen. The essential properties of base asphalt and ASAs could be found in our published paper [16]. Crumb rubber was processed under ambient conditions, the size was 40 mesh (0.425 mm). 2.2. Preparation of crumb rubber modified asphalt containing ASA Melt blending method was utilized to prepare crumb rubber modified asphalt (CRMA) containing ASA. Firstly, base asphalt was heated until flow state. Then, 10% crumb rubber and different dosages (0%, 0.25%, 0.50% and 0.75%) ASA were introduced in base asphalt employing a mechanical mixer, and the operating conditions were 177 °C, 1000 rpm and 30 min. Besides, all prepared binders were aged employing rolling thin film oven (RTFO) according to ASTM D 2872 and pressure aging vessel (PAV) according to ASTM D 6521. 2.3. Experimental methods Chemical functional groups of ASAs and CRMA were characterized employing FTIR. Fourier infrared spectrometer from Thermo Nicolet Corp was used, and the operation of FTIR adopted transmission mode. The setting parameters such as wavenumber range, scanning number and resolution were 4000–400 cm1, 32 and 4 cm1, respectively. The rotational viscosity test (135 °C and 165 °C) was conducted employing Brookfield Viscometer in accordance with ASTM D 4402. Both temperature sweep mode and amplitude sweep mode were conducted employing dynamic shear rheometer according to ASTM D 7175. The variation of rheological properties such G*, d, G*/sin d and failure temperature as temperature or shear strain was measured. The high temperature deformation resistance of various CRMA binders after RTFO under repeated loads was assessed employing Multiple Stress Creep and Recovery (MSCR) test according to ASTM D 7405. The percent recovery (R) and non-recoverable creep compliance (Jnr) under 0.1 kPa and 3.2 kPa stress level were measured.
Fig. 1. Infrared spectrums of ASAs and CRMA (a) ASAs and (b) CRMA.
240
J. Tang et al. / Construction and Building Materials 194 (2019) 238–246
Fig. 2. Rotational viscosity of CRMA with various ASAs at 135 °C and 165 °C.
The low temperature performance of various CRMA binders after PAV was assessed employing bending beam rheometer (BBR) test according to ASTM D 6648. The creep stiffness (S) and creep rate (m-value) under 6 °C, 12 °C and 18 °C were measured. Three replicates for each type of binder were measured.
three ASAs are mainly made up of amine substances, many peaks belonging to the amine substances can be found in the infrared spectrums of ASAs. The peak at 3293 cm1 belongs to the stretching vibration of NAH, while both the two peaks at 1651 cm1 and 1557 cm1 are ascribed to the bending vibration of NAH [17,18]. The peak at 1128 cm1 is ascribed to the stretching vibration of aliphatic CAN [17]. In addition, as seen in Fig. 1(b), these weak peaks at 1825 cm1, 1743 cm1, 1710 cm1, 1700 cm1 and 1678 cm1 are ascribed to the stretching vibration of C@O. Furthermore, the peaks at 1825 cm1 and 1743 cm1 originate from anhydride, whereas the peaks at 1710 cm1, 1700 cm1 and 1678 cm1 result from aldehyde, carboxylic acid and ketone, respectively [19]. These substances containing C@O are mainly ascribed to the oxidation of asphalt [19–21], thus their amount in the virgin asphalt is quite little. Based on the above FTIR analysis for the chemical functional groups of ASAs and CRMA, a reaction between amine in ASAs and anhydride in asphalt binder can happen during the mixing process of ASAs and asphalt binder (the specification from ASAs manufacturer also stated that these ASAs are incompatible with strong oxidizing agents, halides, anhydride, etc). The reaction equation is shown below. The reaction products usually are organogels, which can show exceptional thermal and mechanical stability in comparison with the amine substances or anhydrides [22,23].
3. Results and discussion
ð1Þ
3.1. FTIR analysis The infrared spectrums of ASAs and CRMA are displayed in Fig. 1(a) and (b), separately. As the Fig. 1(a) shows, because the
Fig. 3. G* and d values of CRMA with various ASAs before aging (a) M5000, (b) M1 and (c) LOF-6500.
J. Tang et al. / Construction and Building Materials 194 (2019) 238–246
241
Fig. 4. G* and d values of CRMA with various ASAs after RTFO (a) M5000, (b) M1 and (c) LOF-6500.
3.2. Rotational viscosity Influence of different ASAs with different dosages on rotational viscosity at 135 °C and 165 °C of CRMA is displayed in Fig. 2. As the Fig. 2 shows, regardless of the temperatures, as the dosages increase from 0.25% to 0.75%, the viscosity of CRMA with M5000 or M1 increases initially and decreases afterwards, while that of CRMA with LOF-6500 keeps increasing tendency. Furthermore, the CRMA with 0.50% M5000 has the highest viscosity, the increments at 135 °C and at 165 °C are 44.3% and 43.8% of control sample, respectively. The increase in viscosity is ascribed to the organogels formed by mixing the amines in ASAs with the anhydrides in asphalt binder. However, as the dosage of ASA increases, the anhydrides (the amount is quite little) in CRMA are exhausted, the softening effect of ASAs for CRMA (the viscosity of CRMA is much higher than that of three ASAs) becomes more and more evident. Consequently, the viscosity of CRMA starts decreasing when the dosage of ASA exceeds some certain dosage. 3.3. Complex modulus and phase angle The G* and d of CRMA with various ASAs before aging are displayed in Fig. 3. As seen in Fig. 3(a) and (b), with the dosage of M5000 or M1 increasing, the G* firstly increases and then decreases. The CRMA with 0.50% M5000 or 0.50% M1 shows the highest G*. These results are consistent with the rotational viscosity result. As seen in Fig. 3(c), although there is no similar regularity to M5000 or M1 by analyzing the G* of CRMA with three dosages LOF-6500, the CRMA with LOF-6500 shows the higher G*
than the CRMA without LOF-6500. Furthermore, the enhancement in G* for M1 is more obvious compared with M5000 and LOF-6500. Besides, as seen in Fig. 3, regardless of the ASA types, the addition of ASA with different dosages can decrease the d of CRMA, indicating that the elastic behavior is enhanced when the dosages are limited to the 0.75% range. For M5000 or M1, the CRMA with 0.25% has the lowest d, whereas the CRMA with 0.50% LOF-6500 shows the lowest d. Above results that both the enhancement in G* and the reduction in d are also caused by the organogels formed after adding ASA in CRMA. Fig. 4 shows the G* and d of CRMA with various ASAs after RTFO. As seen in Fig. 4, except for 0.75% M1 and 0.25% LOF-6500, other ASAs increase the G* of CRMA after RTFO. Moreover, regardless of the ASA types, the CRMA with 0.50% has the highest G* (the difference for the CRMA with M1 between 0.25% and 0.50% is quite little). Besides, for M5000 and M1, various dosages of ASA can reduce the d of CRMA after RTFO. However, as the dosage increases, the change in G* and d of CRMAs with three ASAs does not have obvious regularity. These irregular results may be caused by various factors. Four possible factors as follows: 1) After RTFO, some new anhydrides in CRMA are produced, which in turn restarts the reaction (1); 2) Some amines in ASAs belong to active antioxidants, which can retard the hardening of CRMA during RTFO [24,25]; 3) The amine substances in three ASAs are different. The main ingredients of M5000 are alkylamines, alkanol amines and alkylene amines, while the main ingredient of M1 and LOF-6500 are fatty amines derivatives and amidoamines respectively [16]; 4) ASAs have softening effect on CRMA when the amount of ASAs exceeds a certain dosage.
242
J. Tang et al. / Construction and Building Materials 194 (2019) 238–246
Fig. 5. G*/sin d of CRMA with various ASAs at various temperatures before and after RTFO (a) M5000, (b) M1 and (c) LOF-6500.
Fig. 6. Failure temperature of CRMA with various ASAs (a) before aging and (b) after RTFO.
3.4. Rutting resistance factor Rutting resistance factor (G*/sin d) of CRMA with various ASAs at various temperatures before and after RTFO is displayed in Fig. 5. As Fig. 5(a)–(c) show, before aging, interfusing ASAs increases the G*/sin d of CRMA irrespective of the ASA types and dosages. Furthermore, the CRMA with M1 shows the higher G*/sin d than the CRMA with M5000 or LOF-6500. The result illustrates that the interfusion of ASAs can enhance the rutting resistance of CRMA, which is also attributed to the formed organogels after adding ASAs in CRMA.
Additionally, as seen in Fig. 5, after RTFO, the G*/sin d of various CRMA binders obviously increases compared with unaged CRMA binders. This is because RTFO aging leads to the volatilization of light constituents and the conversion of aromatics and resins to asphaltenes in asphalt binder [26]. Except for 0.75% M1 and 0.25% LOF-6500, other ASAs enhance the G*/sin d of CRMA after RTFO. Furthermore, for M5000 or LOF-6500, the CRMA with 0.50% has the highest G*/sin d, while the CRMA with 0.25% M1 shows the highest G*/sin d. However, there is no obvious regularity that the variation in G*/sin d of CRMA with ASAs as the dosage increases.
J. Tang et al. / Construction and Building Materials 194 (2019) 238–246
243
Fig. 7. Jnr and R for CRMA with various ASAs at 76 °C under 0.1 kPa and 3.2 kPa (a) Jnr-0.1, (b) R-0.1, (c) Jnr-3.2 and (d) R-3.2.
3.5. Failure temperature The failure temperature (before aging, G*/sin d = 1.0 kPa; after RTFO, G*/sin d = 2.2 kPa) is usually utilized to confirm the high temperature performance grade of asphalt binder. As Fig. 6(a) shows, before aging, the addition of ASAs can increase the failure temperature of CRMA. Moreover, compared with various dosages for each type of ASA, the CRMAs with 0.50% M5000, 0.50% M1 or 0.75% LOF-6500 show the highest failure temperature, the increments relative to control sample are 1.3 °C, 2.3 °C and 1.3 °C respectively. Additionally, as Fig. 6(b) shows, after RTFO, except for 0.75% M1 and 0.25% LOF-6500, other ASAs can increase the failure temperature of CRMA after RTFO. The CRMAs with 0.50% M5000, 0.25% M1 or 0.50% LOF-6500 show the highest failure temperature, the increments relative to control sample are 4.1 °C, 4.5 °C and 2.8 °C respectively. 3.6. MSCR test The Jnr and R for CRMA with various ASAs after RTFO at 76 °C under 0.1 kPa and 3.2 kPa are shown in Fig. 7. As seen in Fig. 7(a) and (c), regardless of the stress levels, except for 0.75% M1 and 0.25% LOF-6500, other ASAs can decrease the Jnr of CRMA after RTFO at 76 °C. It suggests that the interfusion of ASAs can enhance the deformation resistance of CRMA at high temperature. Moreover, the CRMAs with 0.50% M5000, 0.25% M1 and 0.50% LOF6500 show the most obvious improvement. Besides, as seen in Fig. 7(b) and (d), irrespective of the stress levels, the CRMAs with various ASAs (except for 0.75% M1 and 0.25% LOF-6500) show
the higher R than control sample. This result suggests that the addition of ASAs enhances the elastic response of CRMA. Above results indicate that three ASA with various dosages can improve the rutting resistance of CRMA under repeated loads, which is in accordance with the results from G*/sin d. 3.7. Amplitude sweep test A linear region of asphalt binder may be defined at small strains where the G* is relatively independent of shear strain. The region will change with the magnitude of G*. According to AASHTO T 315-12, the linear region is defined as the range in strains where the G* is 95% or more of the zero-strain value. Fig. 8 shows, before aging, the G* and d values of CRMA with various ASAs during various strains at 76 °C. Based on the G* data, it can be determined that the shear strain range from 0.01 to 0.1 is the linear region of all binders before aging. It means that after adding various ASAs the G* of CRMA is still relatively independent of shear strain when its range is from 0.01 to 0.1. Additionally, as Fig. 8 shows, the interfusion of various ASAs reduces the d of CRMA. It indicates that the CRMAs with ASA have the more elastic components than control sample. Consequently, the deformation resistance of the CRMAs with ASA at high temperature is better. This result is in accordance with the results from temperature sweep test. Fig. 9 shows, after RTFO, the G* and d values of CRMA with various ASAs during various strains at 76 °C. As seen in Fig. 9(a), the G* data shows that the strain ranging from 0.01 to 0.1 is linear viscoelastic range of the CRMA with various dosages M5000 after RTFO. Moreover, the CRMA with M5000 shows the lower d
244
J. Tang et al. / Construction and Building Materials 194 (2019) 238–246
Fig. 8. G* and d values of CRMA with various ASAs before aging during various strains at 76 °C (a) M5000, (b) M1 and (c) LOF-6500.
compared with control sample. However, as seen in Fig. 9(b), the G* data implies that introducing M1 (especially for 0.75% dosage) greatly narrows the linear viscoelastic range of CRMA after RTFO. Additionally, as seen in Fig. 9(c), the G* data also indicates that adding LOF-6500 (aside from 0.75% LOF-6500) significantly reduces the linear viscoelastic range of CRMA after RTFO. Above results suggest that the addition of M1 or LOF-6500 increases the sensibility of CRMA after RTFO to shear strain, while the M5000 has no influence on that of CRMA after RTFO to shear strain.
PG 76-22 with control sample. However, for M1, the CRMA with 0.25% or 0.75% dosage has the PG 76-22, while the CRMA with 0.50% dosage increases one high temperature grade and decreases one low temperature grade. Meanwhile, for LOF-6500, various dosages LOF-6500 do not change the high temperature grade, whereas they decrease one low temperature grade. Above results suggest that M5000 and M1 (except for 0.50% dosage) have no influence on the PG of CRMA, while LOF-6500 can decrease one low temperature grade of CRMA.
3.8. BBR test
4. Conclusions
BBR test is conducted to evaluate the low temperature performance of asphalt binders. Fig. 10 shows the S and m-value of CRMA with various ASAs after PAV at various temperatures. As seen in Fig. 10, irrespective of the ASA types and dosages, adding ASAs increases the S and decreases the m-value. This result illustrates that three ASAs can weaken the low temperature performance of CRMA after PAV, which may be attributed to the formed organogels. Compared with M5000 and M1, the enhancement in S and the reduction in m-value for the CRMA with LOF-6500 are more obvious. Furthermore, for M1 and LOF-6500, the CRMA with 0.50% dosage has the highest S and the lowest m-value, whereas the CRMA with 0.75% dosage M5000 has the highest S and the lowest m-value.
In this research, the influence of three liquid ASAs with different dosages on the rheological properties of CRMA was studied. The main results are as follows:
3.9. Performance grade Performance grade (PG) is critical indicator assessing the high and low temperature performance of asphalt binder. The PG of CRMA with various ASAs is displayed in Table 1. As illustrated in Table 1, the CRMAs with various dosages M5000 show the same
(1) Based on the FTIR analysis, many functional groups containing NAH exist in three ASAs, and a small number of aldehydes exist in CRMA. Thus the reaction between amine and anhydride can happen, and the products usually are organogels which can exhibit exceptional thermal and mechanical stability compared with amine substances or anhydrides. (2) After adding three ASAs with 0.25%–0.75% dosages, the rotational viscosity, G*, G*/sin d and failure temperature of CRMA before aging are enhanced, while the d is reduced. It implies that the high temperature stability of CRMA is enhanced. Moreover, the CRMAs with 0.50% M5000, 0.50% M1 and 0.75% LOF-6500 show the highest enhancement. (3) Three ASAs (except for 0.75% M1 and 0.25% LOF-6500) can enhance the G*, G*/sin d and failure temperature of CRMA after RTFO, whereas reduce the Jnr, demonstrating that the
J. Tang et al. / Construction and Building Materials 194 (2019) 238–246
Fig. 9. G* and d values of CRMA with various ASAs after RTFO during various strains at 76 °C (a) M5000, (b) M1 and (c) LOF-6500.
Fig. 10. S and m-value of CRMA with various ASAs after PAV at various temperatures (a) M5000, (b) M1 and (c) LOF-6500.
245
246
J. Tang et al. / Construction and Building Materials 194 (2019) 238–246
Table 1 PG of CRMA with various ASAs. CRMA types Control sample CRMA + M5000
Performance grade 0.25% 0.50% 0.75%
76–22 76–22 76–22 76–22
CRMA + M1
0.25% 0.50% 0.75%
76–22 82–16 76–22
CRMA + LOF-6500
0.25% 0.50% 0.75%
76–16 76–16 76–16
high temperature stability of CRMA after RTFO is also enhanced. Besides, the CRMAs with 0.50% M5000, 0.25% M1 and 0.50% LOF-6500 show the most obvious improvement. (4) According to the amplitude sweep test results, the introduction of three ASAs with 0.25%–0.75% dosages does not change the linear viscoelasticity of CRMA before aging when the shear strain range is from 0.01 to 0.1. However, after RTFO, M1 and LOF-6500 (aside from 0.75% dosage) significantly reduce the linear viscoelastic range of CRMA. (5) Adding three ASAs with 0.25%-0.75% dosages increases the S and reduces the m-value of CRMA after PAV, suggesting that the low temperature performance of CRMA is weakened. Furthermore, compared with M5000 and M1, LOF-6500 shows the more serious influence. PG analysis indicates that M5000 and M1 (except for 0.50% dosage) have no influence on the PG of CRMA, while LOF-6500 can decrease one low temperature grade of CRMA. Conflict of interest None. Acknowledgements This work was supported by the Hunan Provincial Natural Science Foundation of China (No. 2017JJ3015), the Transportation Science and Technology Development and Innovation Project of Hunan Province (No. 201705), the Science and Technology Planning Project of Changsha (Nos. kc1703038, kq1706018) and. The authors gratefully acknowledge their financial support. References [1] G. Airey, Rheological properties of styrene butadiene styrene polymer modified road bitumens, Fuel 82 (2003) 1709–1719.
[2] M. García-Morales, P. Partal, F.J. Navarro, C. Gallegos, Effect of waste polymer addition on the rheology of modified bitumen, Fuel 85 (2006) 936–943. [3] B.V. Kök, M. Yilmaz, M. Guler, Evaluation of high temperature performance of SBS+Gilsonite modified binder, Fuel 90 (2011) 3093–3099. [4] G. Polacco, S. Filippi, F. Merusi, G. Stastna, A review of the fundamentals of polymer-modified asphalts: asphalt/polymer interactions and principles of compatibility, Adv. Colloids Interface Sci. 224 (2015) 72–112. [5] Z.G. Feng, J.Y. Yu, The research for high-performance SBR compound modified asphalt, Constr. Build. Mater. 24 (2010) 410–418. [6] J. Shen, S. Amirkhanian, The influence of crumb rubber modifier (CRM) microstructures on the high temperature properties of CRM binders, Int. J. Pavement Eng. 6 (2007) 265–271. [7] S.K. Palit, K.S. Reddy, B.B. Pandey, Laboratory evaluation of crumb rubber modified asphalt mixes, J. Mater. Civ. Eng. 16 (2004) 45–53. [8] Q. Wang, S. Li, X. Wu, S. Wang, C. Ouyang, Weather aging resistance of different rubber modified asphalts, Constr. Build. Mater. 106 (2016) 443–448. [9] S. Kim, S.J. Lee, Y.B. Yun, K.W. Kim, The use of CRM-modified asphalt mixtures in Korea: evaluation of high and ambient temperature performance, Constr. Build. Mater. 67 (2014) 244–248. [10] B. Shirini, R. Imaninasab, Performance evaluation of rubberized and SBS modified porous asphalt mixtures, Constr. Build. Mater. 107 (2016) 165–171. [11] M. Arabani, S.A. Tahami, G.H. Hamedi, Performance evaluation of dry process crumb rubber-modified asphalt mixtures with nanomaterial, Road Mater. Pavement 19 (2018) 1241–1258. [12] V.S. Punith, F. Xiao, S.N. Amirkhanian, Effects of lime content on moisture susceptibility of rubberized stone matrix asphalt mixtures using warm mix additives in terms of statistical analysis, J. Mater. Civ. Eng. 24 (2012) 1431– 1440. [13] H. Yu, Z. Leng, Z. Dong, Z. Tan, F. Guo, J. Yan, Workability and mechanical property characterization of asphalt rubber mixtures modified with various warm mix asphalt additives, Constr. Build. Mater. 175 (2018) 392–401. [14] F. Xiao, S.N. Amirkhanian, Effects of liquid antistrip additives on rheology and moisture susceptibility of water bearing warm mixtures, Constr. Build. Mater. 24 (2010) 1649–1655. [15] D.W. Park, W.J. Seo, J. Kim, H.V. Vo, Evaluation of moisture susceptibility of asphalt mixture using liquid anti-stripping agents, Constr. Build. Mater. 144 (2017) 399–405. [16] C.Z. Zhu, G.Q. Xu, H.L. Zhang, F.P. Xiao, S. Amirkhanian, C.F. Wu, Influence of different anti-stripping agents on the rheological properties of asphalt binder at high temperature, Constr. Build. Mater. 164 (2018) 317–325. [17] G. Yang, W.S. Chang, D.T. Hallinan Jr., A convenient phase transfer protocol to functionalize gold nanoparticles with short alkylamine ligands, J. Colloids Interface Sci. 460 (2015) 164–172. [18] X. Yang, T. Mei, J. Yang, C. Zhang, M. Lv, X. Wang, Synthesis and characterization of alkylamine-functionalized graphene for polyolefin-based nanocomposites, Appl. Surf. Sci. 305 (2014) 725–731. [19] H. Yao, Q. Dai, Z. You, Fourier Transform Infrared Spectroscopy characterization of aging-related properties of original and nano-modified asphalt binders, Constr. Build. Mater. 101 (2015) 1078–1087. [20] D. Lesueur, The colloidal structure of bitumen: consequences on the rheology and on the mechanisms of bitumen modification, Adv. Colloids Interface Sci. 145 (2009) 42–82. [21] S. Wu, Z. Zhao, Y. Xiao, M. Yi, Z. Chen, M. Li, Evaluation of mechanical properties and aging index of 10-year field aged asphalt materials, Constr. Build. Mater. 155 (2017) 1158–1167. [22] S.C. Xu (Ed.), Organic Chemistry, Higher Education Press, Beijing, 2014, pp. 377–378 (in Chinese). [23] R.D. Mahapatra, J. Dey, Instant gels from mixtures of amines and anhydrides at room temperature, Colloids Surf. B 147 (2016) 422–433. [24] A. James, D. Stewart, The use of fatty amine derivatives to slow down the agehardening process in bitumen Rome, in: Proc. of International Symposium Chemistry of Bitumens, 1991, pp. 671–684. [25] I. Gawel, F. Czechowski, J. Kosno, An environmental friendly anti-ageing additive to bitumen, Constr. Build. Mater. 110 (2016) 42–47. [26] X. Lu, I. Ulf, Effect of ageing on bitumen chemistry and rheology, Constr. Build. Mater. 16 (2002) 15–22.