scholarly journals Rheology-Chemical Based Procedure to Evaluate Additives/Modifiers Used in Asphalt Binders for Performance Enhancements: Phase 2

2021 ◽  
Author(s):  
Punit Singhvi ◽  
◽  
Javier García Mainieri ◽  
Hasan Ozer ◽  
Brajendra Sharma ◽  
...  
Keyword(s):  
Large Strain ◽  
Asphalt Binder ◽  
Performance Testing ◽  
Alternative Methods ◽  
Asphalt Binders ◽  
High Mass ◽  
Index Test ◽  
Modified Binders ◽  
Modified Binder ◽  
Flexibility Index

The increased use of softer binders in Illinois over the past decade is primarily attributed to the increased use of recycled materials in asphalt pavement construction. The shift in demand of using PG 58-28 over PG 64-22 has resulted in potential alternative methods to produce softer binders more economically using proprietary products. However, there are challenges in using these proprietary products for asphalt modification because of uncertainty in their long-term performance and significant variability in binder chemistry. The current SuperPave performance grading specification for asphalt binders is insufficient in differentiating binders produced from these modifiers. Therefore, the objective of this study is to evaluate the performance of various softener-type asphalt binder modifiers using a wide array of rheological and chemistry tests for their integration into the Illinois Department of Transportation’s material specifications. The small-strain rheological tests and their parameters allowed for consistent grouping of modified binders and can be used as surrogates to identify performing and nonperforming asphalt binders. A new parameter, Δ|G*|peak τ, was developed from the linear amplitude sweep test and showed potential to discriminate binders based on their large-strain behavior. Chemistry-based parameters were shown to track aging and formulation changes. The modifier sources were identified using fingerprint testing and were manifested in the modified binder chemical and compositional characteristics. The two sources of base binders blended with the modifiers governed the aging rate of the modified binders. Mixture performance testing using the Illinois Flexibility Index Test and the Hamburg Wheel-Track Test were consistent with the rheological and chemical findings, except for the glycol amine-based modified binder, which showed the worst cracking performance with the lowest flexibility index among the studied modifiers. This was contrary to its superior rheological performance, which may be attributed to lower thermal stability, resulting in high mass loss during mixing. According to the characterization of field-aged binders, laboratory aging of two pressurized aging vessel cycles or more may represent realistic field aging of 10 to 15 years at the pavement surface and is able to distinguish modified binders. Therefore, an extended aging method of two pressurized aging vessel cycles was recommended for modified binders. Two different testing suites were recommended for product approval protocol with preliminary thresholds for acceptable performance validated with field-aged data.

scholarly journals Kinetic Viscoelasticity of Crosslinking Epoxy Asphalt

2019 ◽  
Vol 2673 (3) ◽  
pp. 551-560 ◽  
Author(s):  
Panos Apostolidis ◽  
Xueyan Liu ◽  
Martin van de Ven ◽  
Sandra Erkens ◽  
Tom Scarpas
Keyword(s):  
Mechanical Properties ◽  
Asphalt Binder ◽  
Crosslinking Density ◽  
Asphalt Binders ◽  
Experimental Program ◽  
Model Parameters ◽  
Epoxy Asphalt ◽  
Pavement Structures ◽  
Chemical Hardening ◽  
Modified Binder

Epoxy modification of asphalt binders has been recognized as a very effective technology to alter the chemistry of asphaltic materials in such a way that long-lasting pavement structures can be designed. However, the phenomena that are involved to build up the physico-mechanical properties of epoxy asphalt systems are still unknown. The focus of this paper is on understanding the link between chemistry and the mechanical properties of epoxy asphalt binders during the thermo-irreversible process of chemical hardening. For this purpose, a constitutive model for predicting the evolution of cure-induced stresses in epoxy asphalt binders is proposed, and an experimental program was developed to determine the model parameters. The cure dependency of physico-mechanical parameters of modified binder was obtained and imported into the model to simulate the build-up of material properties during (non-)isothermal hardening of epoxy asphalt binder. The model is implemented in a commercially finite element tool by coupling the chemical, thermal, and mechanical phenomena with multi-physics strategies, and the results are analyzed to identify the influence of different heating conditions on the crosslinking density and subsequently on stress build-up. It was found that the amount of stress build-up during curing was strongly dependent on the heating conditions, and a higher rate of stress build-up was observed at higher applied temperatures. In other words, the processing conditions during in-plant material production or in-field manufacturing of structures made by epoxy asphalt systems affect the material hardening and subsequently the desired functionalities of pavement structures.

scholarly journals Performance of Warm-Mixed Flame Retardant Modified Asphalt Binder

2019 ◽  
Vol 9 (7) ◽  
pp. 1491
Author(s):  
Ruixia Li ◽  
Kaiwei Zhang ◽  
Jiahui Wu ◽  
Wenjuan Liu
Keyword(s):  
High Temperature ◽  
Flame Retardant ◽  
Performance Test ◽  
Asphalt Binder ◽  
Negative Influence ◽  
Viscosity Reduction ◽  
Asphalt Binders ◽  
Index Test ◽  
Flame Resistance ◽  
Limiting Oxygen Index

In order to analyze the effect of flame retardant and warm mix asphalt (WMA) additives-Sasobit on the flame-retardant performance and pavement performance of asphalt binder, the limiting oxygen index test, conventional performance test, and Superpave evaluation index tests were performed on asphalt binders in the study. The test results show that flame retardant can effectively improve the flame resistance of asphalt binder, while Sasobit has a certain combustion-supporting effect. Therefore, when warm-mixed flame-retardant technology is applied, the concentration of Sasobit should be controlled appropriately. These two modifiers can significantly enhance the high-temperature performance of asphalt binder, but both of them have a slight negative influence on the low-temperature cracking resistance. Sasobit can substantially reduce the high-temperature viscosity of asphalt binder, which helps to improve the construction workability of asphalt binder, while the flame retardant adversely affects the viscosity reduction effect of Sasobit to a certain extent, but the overall impact is not large.

Quantification of the Effect of Binder Source on Flexibility of Long-Term Aged Asphalt Concrete

2020 ◽  
Vol 2674 (9) ◽  
pp. 605-616
Author(s):  
Zehui Zhu ◽  
Punit Singhvi ◽  
Uthman Mohamed Ali ◽  
Hasan Ozer ◽  
Imad L. Al-Qadi
Keyword(s):  
Asphalt Concrete ◽  
Asphalt Binder ◽  
Rheological Parameters ◽  
Index Test ◽  
Performance Grade ◽  
Aged Asphalt ◽  
Aging Conditions ◽  
Aged Binder ◽  
Flexibility Index

Asphalt concrete (AC) aging reduces the resistance of flexible pavements to fatigue, thermal, and block cracking. Therefore, it is critical to understand the effects of AC aging on flexible pavement serviceability. Binder source has a significant effect on AC long-term aging. Therefore, it is necessary to develop a reliable, practical, and systematic method to quantify the effect of binder source on AC cracking resistance. Seven laboratory mixes were designed and produced at three asphalt binder replacement (ABR) levels using various binders, but same binder performance grade (PG). The AC mixes were tested using the Illinois Flexibility Index Test (I-FIT) under unaged and long-term aged conditions. Standard Superpave tests and temperature-frequency sweep tests, were conducted on virgin binders under various aging conditions. By comparing the binder rheological parameters and flexibility index (FI) of long-term aged AC specimens, the [Formula: see text] and m-value after 40-h of aging using a pressure aging vessel (PAV) were identified as valid indicators to reflect the effects of the binder source on AC long-term flexibility. A minimum [Formula: see text] of -8°C and m-value of 0.280 were proposed as the preliminary thresholds. A new parameter, [Formula: see text], which is defined as the m-value of 20-h PAV-aged binder minus the m-value of a 40-h PAV-aged binder, correlates well with the aging rate of AC. A binder with a high [Formula: see text] may induce an excessive drop in flexibility after long-term aging.

scholarly journals High-Temperature Performance Evaluation of Asphaltenes-Modified Asphalt Binders

Molecules ◽  
2020 ◽  
Vol 25 (15) ◽  
pp. 3326
Author(s):  
Amirhossein Ghasemirad ◽  
Nura Bala ◽  
Leila Hashemian
Keyword(s):  
High Temperatures ◽  
High Performance ◽  
Asphalt Binder ◽  
Viscoelastic Behavior ◽  
Asphalt Binders ◽  
Performance Grade ◽  
Modified Binders ◽  
Linear Viscoelastic Behavior ◽  
Linear Viscoelastic ◽  
Gravity Driven

Asphalt binder comprises four main fractions—asphaltenes (A), saturates (S), aromatics (A), and resins (R)—referred to as “SARA”. Asphaltenes plays an important role in determining the linear viscoelastic behavior of asphalt binders. In this research, asphaltenes are added as a distinct modifier to improve the performance properties of asphalt binder. The modified binders are aged using a rolling thin film oven. A dynamic shear rheometer is then used to measure the rheological properties of the binders at high temperatures. Changes in the chemical composition of the modified binders are also studied through the determination of SARA fractions, using precipitation and gravity-driven chromatography methods. The rheological results show that asphaltenes improve the stiffness and elasticity of asphalt binder. It is also shown that the addition of asphaltenes raises the high Performance grade (PG) temperature of the asphalt binder, with every 6% of asphaltenes added resulting in a one-interval increase in high PG temperature grade. SARA analysis shows that the increase in polar fraction content due to the addition of asphaltenes causes the stiffness, elasticity, and viscosity of asphalt binders to increase. The results indicate that asphaltenes are an effective yet inexpensive additive to improve asphalt binder properties at high temperatures.

PHYSICAL PROPERTIES AND STORAGE STABILITY OF GEOPOLYMER MODIFIED ASPHALT BINDER

2016 ◽  
Vol 78 (7-2) ◽  
Author(s):  
Ahmad Nazrul Hakimi Ibrahim ◽  
Nur Izzi Md. Yusoff ◽  
Norliza Mohd Akhir ◽  
Muhamad Nazri Borhan
Keyword(s):  
Physical Properties ◽  
Storage Stability ◽  
Permanent Deformation ◽  
Asphalt Binder ◽  
Asphalt Binders ◽  
Modified Asphalt ◽  
Modified Asphalt Binder ◽  
Potential Alternative ◽  
Modified Binder ◽  
And Storage

This study was conducted to investigate the physical properties and storage stability of the 80/100 penetration grade asphalt modified with geopolymer. In this research, fly ash and alkali activators, namely sodium silicate (Na2SiO3) and sodium hydroxide (NaOH), were used as geopolymer components. The penetration, Ring and Ball softening point, ductility, and viscosity tests were conducted to determine the physical properties of geopolymer modified asphalt (GMA). Five samples of asphalt binders with varying percentages of geopolymer, namely 0, 3, 5, 7 and 9%, by weight of asphalt binder were studied. Results show that geopolymer has good compatibility with asphalt binder. The addition of geopolymer into asphalt binder resulted in improved permanent deformation resistance of the modified binder compared to that of the conventional asphalt. In conclusion, geopolymer could be considered as a potential alternative in the modification of the properties of asphalt binder.

scholarly journals Characterization of Recovery in Asphalt Binders

Materials ◽  
2020 ◽  
Vol 13 (4) ◽  
pp. 920 ◽  
Author(s):  
Fuquan Ma ◽  
Xue Luo ◽  
Zhiyi Huang ◽  
Jinchang Wang
Keyword(s):  
Activation Energy ◽  
Internal Stress ◽  
Asphalt Binder ◽  
Asphalt Binders ◽  
Asphalt Pavements ◽  
Loading Conditions ◽  
Recovery Model ◽  
Modified Asphalt Binder ◽  
Modified Binder ◽  
Styrene Butadiene

The recovery property of asphalt binders plays an important role in the performance and service life of asphalt pavements. Since the internal stress is the driving force for the recovery of asphalt binders, the accurate measurement of the internal stress is full of significance. Based on this rationale, this paper aims to measure the internal stress of asphalt binders using a creep and step-loading recovery (CSR) test and characterizing the recovery behaviors by the internal stress. One base asphalt binder and one styrene–butadiene–styrene (SBS)-modified binder are selected in this study. The key elements of the CSR test are carefully designed and its accuracy is verified in three aspects, including the loading conditions, the effect of disturbance by step-loads, and accuracy of measured internal stress. Then, a kinetics-based recovery model is proposed to evaluate and predict the recovery properties of asphalt binders from its causal relationship. The constant-rate recovery activation energy indicates a major difference with nondestructive and destructive loading conditions, while the fast-rate recovery activation energy keeps almost constant regardless of the loading conditions. After that, the healing activation energy is calculated by using the kinetics-based recovery model and the results indicate that SBS modified asphalt binder shows better healing abilities than a base binder.

scholarly journals Optical Characterization of Asphalt Binders Containing Wax Additives

2020 ◽  
Vol 2020 ◽  
pp. 1-7
Author(s):  
Mithil Mazumder ◽  
Raju Ahmed ◽  
Moon-Sup Lee ◽  
Soon-Jae Lee
Keyword(s):  
Optical Properties ◽  
Aging Process ◽  
Significant Contribution ◽  
Asphalt Binder ◽  
Optical Characterization ◽  
Crumb Rubber ◽  
Asphalt Binders ◽  
Oxidative Aging ◽  
Modified Binder

In between thermal-oxidative (heat and oxygen) and photo-oxidative (ultraviolet irradiation and oxygen) aging process of bitumen, photo-oxidative aging mainly depends on the optical properties of the asphalt binder. The higher the reflection (or the lower the absorption of the binders), the better the pavement serviceability. The literature review indicates that there is limited research conducted on the optical properties of the binder with wax additives. In this paper, the optical properties of commonly used binders (PG 64-22, Rubber modified binder, and SBS modified binder) containing wax additives (LEADCAP and Sasobit) were investigated using UV-Vis spectrometer. The result of this study showed that (1) the addition of modifiers (crumb rubber and SBS) with the base binder slightly increases the absorption of the binder; (2) the binder types and aging level have significant contribution on optical properties; (3) in general, the aged binders were observed to have higher reflectivity compared to the unaged binders; and (4) the addition of wax additives is observed to have a significant effect on the optical properties.

scholarly journals Characterization of thermal storage stability of waste plastic pyrolytic char modified asphalt binders with sulfur

PLoS ONE ◽  
2021 ◽  
Vol 16 (3) ◽  
pp. e0248465
Author(s):  
Abhinay Kumar ◽  
Rajan Choudhary ◽  
Ankush Kumar
Keyword(s):  
Storage Stability ◽  
Asphalt Binder ◽  
Principal Component ◽  
Thermal Storage ◽  
Asphalt Binders ◽  
Waste Plastic ◽  
Modified Asphalt ◽  
Modified Binders ◽  
Pyrolytic Char

Pyrolysis has gained a strong interest in recent times for sustainable treatment and recovery of energy-rich products from different wastes including plastic. Waste plastic pyrolytic char (PPC) generated as a carbonaceous by-product in the pyrolysis process, is gaining attention as an asphalt binder modifier. Adequate thermal storage stability is an essential requirement for a modified asphalt binder to ensure that the composite offers integrity and homogeneous properties during its storage, handling and transportation in the field. The objective of this study was to evaluate and characterize the thermal storage stability properties of PPC modified binders. PPC modified asphalt binders were fabricated and evaluated at multiple dosages of sulfur as a cross-linking agent. In addition to the conventionally used softening point difference (SPD), characterization of thermal storage stability was attempted using rheology-based separation indices (SIs) derived through temperature sweep, frequency sweep, and multiple stress creep and recovery (MSCR) tests. These rheological SIs were based on complex modulus (G*), Superpave rutting parameter (G*/sin δ), Shenoy rutting parameter (SRP), zero shear viscosity (ZSV), and MSCR Jnr (at three stress levels 0.1, 3.2 and 10 kPa). Two formulations of each rheology-based separation index were studied: (1) ratio, and (2) maximum-average difference formulations. The temperature and frequency dependencies of rheological SIs were also evaluated. Further, the Fourier transform infrared spectroscopy (FTIR) was used to characterize storage stability by comparing the chemical functionalities of the PPC modified binders. A 0.3% dosage of sulfur was found to produce the best results considering all SPD, rheology-based SIs and FTIR. Principal component analysis showed that the ratio and maximum-average formulations had similar contributions to the first principal component accounting for more than 99% of the variability.

Development of a Simple Fatigue Cracking Test for Asphalt Binders

2017 ◽  
Vol 2632 (1) ◽  
pp. 79-87 ◽  
Author(s):  
Fujie Zhou ◽  
Pravat Karki ◽  
Soohyok Im
Keyword(s):  
Fatigue Test ◽  
Fatigue Resistance ◽  
Asphalt Binder ◽  
Fatigue Cracking ◽  
Asphalt Binders ◽  
Index Test ◽  
Test Results ◽  
Long Time ◽  
Aging Conditions ◽  
Binder Aging

Current Superpave® PG specification uses parameter | G*|sin(δ) to quantify asphalt binder fatigue resistance. The parameter’s effectiveness has been debated for a long time. AASHTO recently adopted the linear amplitude sweep test as a provisional standard, AASHTO TP 101-12. The authors evaluated the sensitivity of this standard to different aging conditions: unaged original binders, rolling thin-film oven-aged binders, and 20- to 80-h pressure aging vessel–aged binders. Test results showed, in many cases, longer predicted fatigue lives for more-aged binders. Thus this study developed a simple fatigue cracking test for asphalt binders. In this new test, the pure linear amplitude sweep (PLAS) test, peak shear strain was increased linearly from 0% to 30% over a course of 3,000 oscillatory cycles. A new fatigue parameter, the fatigue resistance energy index (FREI), was derived with fracture mechanics. The PLAS test and FREI parameter were sensitive to both binder aging conditions and rejuvenator type and dosage. Four laboratory mixtures were employed to evaluate the correlation between this new binder fatigue test and the two mixture cracking tests: the Texas overlay test and the Illinois flexibility index test. The results showed that the PLAS and FREI correlated well with the mixture cracking tests. Additionally, the proposed method was preliminarily verified with the FHWA accelerated loading facility test, and a fair relationship with the full-scale fatigue test data was observed. It is obvious that the PLAS and associated FREI need further validation through more field test sections.

Evaluation of Degradation of SBS Modified Asphalt Binder Because of RTFO, PAV, and UV Aging using a Novel Extensional Deformation Test

2019 ◽  
Vol 2673 (6) ◽  
pp. 447-457 ◽  
Author(s):  
Roksana Hossain ◽  
Nazimuddin M. Wasiuddin
Keyword(s):  
Asphalt Binder ◽  
Uv Aging ◽  
Extensional Deformation ◽  
Modified Binders ◽  
Modified Asphalt Binder ◽  
Shear Mixing ◽  
Deformation Test ◽  
Modified Binder ◽  
Aged Binder ◽  
Styrene Butadiene

Styrene-butadiene-styrene (SBS) modified PG 64-22 and PG 76-22 binders are studied to investigate the degradation of polymer because of aging applied by: rolling thin film oven (RTFO), pressure aging vessel (PAV), and ultraviolet (UV). Upon observing the temperature increment of unmodified binder during high shear mixing, a polymer mixing procedure has been established. SBS (2%, 4%, and 6%), polyphosphoric acid (PPA) (0.5%, 2%, and 3.5%), and PPA (2%)-SBS (0.5%, 2%, and 3.5%) are mixed with PG 64-22 binder. Sentmanat extensional rheometer, based on dynamic shear rheometer, is used to investigate the extensional deformation characteristics in which SBS modified binders exhibit both first peak elongation force, F1, and second peak elongation force, F2, whereas, unmodified binders and PPA modified binders exhibit no F2. SBS is the most effective in increasing F2 with an increasing rate of 1.16N/% of SBS polymer. At 12°C and 16°C, F2 of RTFO aged SBS modified binder reduces, which indicates the polymer is degrading. In the case of PAV aged SBS modified binder, no F2 is found at 12°C and 16°C. With the increment of temperature, the PAV aged sample shows F2, but the value is less than the F2 of the original and RTFO aged binder of similar stiffness (F1). A normalized parameter, F2/F1, also shows that RTFO and PAV aging degrade SBS. Evaluation of UV aged SBS modified binder shows no F2 at any temperature while oven aged binder shows F2 value at similar aging temperature, duration, and thickness, indicating SBS completely degrades because of UV aging.

Sign in / Sign up

Export Citation Format

Share Document