scholarly journals Recent advances in characterizing the “bee” structures and asphaltene particles in asphalt binders

2020 ◽  
Vol 13 (6) ◽  
pp. 697-706
Author(s):  
Yuhong Wang ◽  
Kecheng Zhao ◽  
Fangjin Li ◽  
Qi Gao ◽  
King Wai Chiu Lai
Keyword(s):  
Near Field ◽  
Asphalt Binder ◽  
Optical Microscope ◽  
Asphalt Binders ◽  
Zero Shear Viscosity ◽  
Surface Features ◽  
Asphaltene Content ◽  
Scanning Transmission ◽  
Before And After ◽  
Binder Aging

AbstractThe microscopic surface features of asphalt binders are extensively reported in existing literature, but relatively fewer studies are performed on the morphology of asphaltene microstructures and cross-examination between the surface features and asphaltenes. This paper reports the findings of investigating six types of asphalt binders at the nanoscale, assisted with atomic force microscopy (AFM) and scanning transmission electron microscopy (STEM). The surface features of the asphalt binders were examined by using AFM before and after being repetitively peeled by a tape. Variations in infrared (IR) absorbance at the wavenumber around 1700 cm−1, which corresponds to ketones, were examined by using an infrared s-SNOM instrument (scattering-type scanning near-field optical microscope). Thin films of asphalt binders were examined by using STEM, and separate asphaltene particles were cross-examined by using both STEM and AFM. In addition, connections between the microstructures and binder’s physicochemical properties were evaluated. The use of both microscopy techniques provide comprehensive and complementary information on the microscopic nature of asphalt binders. It was found that the dynamic viscosities of asphalt binders are predominantly determined by the zero shear viscosity of the corresponding maltenes and asphaltene content. Limited samples also suggest that the unique bee structures are likely related to the growth of asphaltene content during asphalt binder aging process, but more asphalt binders from different crude sources are needed to verify this finding.

scholarly journals Impact of Graphene Oxide on Zero Shear Viscosity, Fatigue Life and Low-Temperature Properties of Asphalt Binder

Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 3073
Author(s):  
Abbas Mukhtar Adnan ◽  
Chaofeng Lü ◽  
Xue Luo ◽  
Jinchang Wang
Keyword(s):  
Graphene Oxide ◽  
Fatigue Life ◽  
Low Temperature ◽  
Shear Viscosity ◽  
Storage Stability ◽  
Asphalt Binder ◽  
Asphalt Binders ◽  
Test Results ◽  
Zero Shear Viscosity ◽  
Modified Asphalt

This study has investigated the impact of graphene oxide (GO) in enhancing the performance properties of an asphalt binder. The control asphalt binder (60/70 PEN) was blended with GO in contents of 0%, 0.5%, 1%, 1.5%, 2%, and 2.5%. The permanent deformation behavior of the modified asphalt binders was evaluated based on the zero shear viscosity (ZSV) parameter through a steady shear test approach. Superpave fatigue test and the linear amplitude sweep (LAS) method were used to evaluate the fatigue behavior of the binders. A bending beam rheometer (BBR) test was conducted to evaluate the low-temperature cracking behavior. Furthermore, the storage stability of the binders was investigated using a separation test. The results of the ZSV test showed that GO considerably enhanced the steady shear viscosity and ZSV value, showing a significant contribution of the GO to the deformation resistance; moreover, GO modification changed the asphalt binder’s behavior from Newtonian to shear-thinning flow. A notable improvement in fatigue life was observed with the addition of GO to the binder based on the LAS test results and Superpave fatigue parameter. The BBR test results revealed that compared to the control asphalt, the GO-modified binders showed lower creep stiffness (S) and higher creep rate (m-value), indicating increased cracking resistance at low temperatures. Finally, the GO-modified asphalt binders exhibited good storage stability under high temperatures.

scholarly journals Investigation of the Effect of Induction Heating on Asphalt Binder Aging in Steel Fibers Modified Asphalt Concrete

Materials ◽  
2019 ◽  
Vol 12 (7) ◽  
pp. 1067 ◽  
Author(s):  
Hechuan Li ◽  
Jianying Yu ◽  
Shaopeng Wu ◽  
Quantao Liu ◽  
Yuanyuan Li ◽  
...  
Keyword(s):  
Induction Heating ◽  
Asphalt Concrete ◽  
Asphalt Binder ◽  
Steel Fibers ◽  
Asphalt Binders ◽  
Carbonyl Index ◽  
Modified Asphalt ◽  
Concrete Damage ◽  
The Difference ◽  
Binder Aging

Induction heating is a valuable technology to repair asphalt concrete damage inside. However, in the process of induction heating, induced particles will release a large amount of heat to act on asphalt binder in a short time. The purpose of this paper was to study the effect of induction heating on asphalt binder aging in steel fibers modified asphalt concrete. The experiments were divided into two parts: induction heating of Dramix steel fibers coated with asphalt binder (DA) and steel wool fibers modified asphalt concrete. After induction heating, the asphalt binders in the samples were extracted for testing aging indices with Fourier Transform Infrared (FTIR), Dynamic Shear Rheometer (DSR), and Four-Components Analysis (FCA) tests. The aging of asphalt binder was analyzed identifying the change of chemical structure, the diversification of rheological properties, and the difference of component. The experiments showed that the binder inside asphalt concrete began aging during induction heating due to thermal oxygen reaction and volatilization of light components. However, there was no peak value of the carbonyl index after induction heating of ten cycles, and the carbonyl index of DA was equivalent to that of binder in asphalt concrete after three induction heating cycles, which indicated the relatively closed environment inside asphalt concrete can inhibit the occurrence of the aging reaction.

The Effect of Asphalt Binder Aging on Fatigue Performance of Evotherm WMA

2012 ◽  
Vol 535-537 ◽  
pp. 1686-1692
Author(s):  
Yong Chun Qin ◽  
Sui Yuan Wang ◽  
Wei Zeng ◽  
Xiao Pei Shi ◽  
Jian Xu ◽  
...  
Keyword(s):  
Fatigue Life ◽  
Asphalt Binder ◽  
Asphalt Mixture ◽  
Warm Mix Asphalt ◽  
Fatigue Tests ◽  
Fatigue Performance ◽  
Asphalt Binders ◽  
Different Temperatures ◽  
Binder Aging ◽  
Lower Production

One of the main benefits advertised with the use of warm mix asphalt (WMA) is the decreasing aging of the asphalt binder resulting from the lower production temperature compared to conventional hot mix asphalt (HMA). Some tests were performed to determine the asphalt binder aging properties from WMA and HMA. Asphalt binders were recovered by extraction and distillation from asphalt mixtures premixed at different temperatures (140°C, 160°C, 180°C for HMA, 100°C and 120°C for WMA) in the mixing plant. Penetration@25°C, softening point (R&B) and rotational Brookfield viscosity tests were carried out. Results show that the aging of asphalt binder increases as the mixing temperature is elevated, and remarkably accelerates at the temperatures higher than 150°C. Warm mix asphalt (for example, mixing temperature at 100°Cor 120°C) can greatly reduce the aging of asphalt. Aging of the asphalt binder is one of the factors that would affect the mixture’s fatigue life. Four-point beam fatigue test samples were mixed and compacted at 140°C for HMA and 120°C for WMA, and fatigue tests with a frequency of 10 Hz and three constant strain levels (150 micro-strain, 300 micro-strain, 450 micro-strain, respectively) were performed. Results show that WMA’s fatigue life was higher than the control HMA, which indicates that it may reduce aging of asphalt binder and improve fatigue performance of asphalt mixture at lower production temperatures.

scholarly journals Laboratory Evaluation of Sustainable PMA Binder Containing Styrene-Isoprene-Styrene (SIS) and Thermoplastic Polyurethane

2020 ◽  
Vol 12 (23) ◽  
pp. 10057
Author(s):  
Hyun Hwan Kim ◽  
Mithil Mazumder ◽  
Soon-Jae Lee ◽  
Moon-Sup Lee
Keyword(s):  
Thermoplastic Polyurethane ◽  
Asphalt Binder ◽  
Asphalt Binders ◽  
Laboratory Evaluation ◽  
Creep Recovery ◽  
Before And After ◽  
Multiple Stress Creep Recovery ◽  
Compaction Processes ◽  
Positive Effect

In this study, thermoplastic polyurethane (TPU) and styrene-isoprene-styrene (SIS) were utilized to enhance asphalt binder properties. Superpave asphalt binder tests and multiple stress creep recovery (MSCR) were conducted to evaluate the physical and rheological performance (viscosity, rutting, and cracking properties) of the asphalt binders before and after short-term aging and after the long-term aging process. The results showed that (i) TPU has a positive effect on workability, including the mixing and compaction processes, which was evident from the reduced binder viscosity; (ii) asphalt binders with TPU and SIS showed better rutting resistance compared to the SIS binders without TPU; (iii) the cracking resistance of asphalt binders was found to be improved significantly with the addition of TPU; and (iv) TPU has the potential to be considered as a sustainable polymer modifier for producing bearable asphalt binders by improving rutting and crack resistance without increasing the melting temperature of the asphalt binders.

Relating Adhesion and Cohesion of Asphalts to the Effect of Moisture on Laboratory Performance of Asphalt Mixtures

2005 ◽  
Vol 1901 (1) ◽  
pp. 33-43 ◽  
Author(s):  
Kunnawee Kanitpong ◽  
Hussain Bahia
Keyword(s):  
Permanent Deformation ◽  
Asphalt Binder ◽  
Asphalt Mixture ◽  
Asphalt Mixtures ◽  
Asphalt Binders ◽  
Fundamental Properties ◽  
Water Conditioning ◽  
Before And After ◽  
Indirect Tensile ◽  
Wheel Tracking

Antistripping additives and polymer modifications are two common modifiers used to improve the fundamental properties of asphalt binders as those properties relate to the performance of asphalt mixtures. Adhesion and cohesion are two important related properties of asphalt binders that can affect asphalt mixture performance before and after water conditioning. The purpose of this study was to quantify the effects of antistripping additives and polymers on the adhesion and cohesion of binders and to relate these effects to the performance of mixtures as measured in the laboratory before and after water conditioning. The performance tests of asphalt mixtures included indirect tensile strength, uniaxial compression permanent deformation, and Hamburg wheel tracking. Asphalt mixtures were produced with different modified binders and with two aggregate types. The binders were modified with antistripping additives and polymers and by chemical treatment and oxidization methods. Granite and limestone were selected as two types of aggregate sources. The results indicate that the performance of asphalt mixtures is highly dependent on modification techniques and water conditioning. The overall performance of polymer-modified mixtures is more desirable than those of unmodified mixtures and of mixtures modified with antistripping additives. Polymers are found to improve rutting performance, adhesion, and cohesion of an asphalt binder. In contrast, the antistripping additive can improve only the adhesion without changing other properties. The results of this study also illustrate that the adhesion and cohesion of an asphalt binder are good indicators of the performance of asphalt mixtures in the laboratory when they are conditioned with water.

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.

Development of a Computer Program for Calculation of the Alpha Parameter in the Linear Amplitude Sweep Test and Comparison with Rheological Parameters

2020 ◽  
Vol 2674 (7) ◽  
pp. 284-298
Author(s):  
Seyed Farhad Abdollahi ◽  
Mehdi Farrokhi ◽  
Nader Tabatabaee
Keyword(s):  
Computer Program ◽  
Fatigue Resistance ◽  
Asphalt Binder ◽  
Relaxation Modulus ◽  
Asphalt Binders ◽  
Rheological Parameters ◽  
Master Curves ◽  
State Highway ◽  
Binder Aging ◽  
Styrene Butadiene

Characterizing and modeling the fatigue performance of an asphalt binder is important when designing asphalt mixtures which can resist premature fatigue failure. Performance grading (PG) standards include the fatigue factor ( G*.sinδ) to evaluate the fatigue resistance of asphalt binders. This criterion seems to be inaccurate, especially when applied to modified asphalt binders. American Association of State Highway and Transportation Officials (AASHTO) TP 101 has been designed to evaluate the fatigue resistance of asphalt binders using Schapery’s work potential theory. The damage evolution rate ( α parameter) is the key element of this method and is calculated from the rheological properties of the undamaged asphalt binder using the slope of the relaxation modulus versus the time on the log-log scale. Owing to the difficulties of conducting the relaxation test, the relaxation modulus is usually obtained using conversion methods. However, AASHTO TP 101 uses a simplified indirect method to calculate α. The present study developed a computer program called RheoSUT with which to construct relaxation master curves using different methods. The relaxation master curves of 27 asphalt binders were evaluated for estimation of the value of α. The results indicated that AASHTO TP 101 yields higher values of α. The results of the sensitivity analysis show that overestimation of α will result in up to about 200% error in the estimation of the fatigue life ( Nf). It is also shown that binder aging and styrene-butadiene-styrene (SBS) modification directly affected the rheological parameters and relaxation master curves. Finally, it is recommended to use the relaxation-master curved based methods of calculation of α instead of the storage-modulus based ones.

Preparation and Properties of Nanoclay/TPS/Asphalt Ternary Binders

2009 ◽  
Vol 620-622 ◽  
pp. 497-500 ◽  
Author(s):  
Shao Peng Wu ◽  
Jin Gang Wang ◽  
Yuan Zhang
Keyword(s):  
Rheological Properties ◽  
High Speed ◽  
Complex Modulus ◽  
Preliminary Investigation ◽  
Asphalt Binder ◽  
Asphalt Binders ◽  
Frequency Sweep ◽  
Modified Asphalt ◽  
Aging Resistance ◽  
Before And After

After a preliminary investigation on the binary asphalt/clay binder, the ternary binder was prepared by adding the nanoclay and TAFPACK-SUPER (TPS) to the original asphalt. The previous research shows that exfoliated/intercalated layers homogeneously are dispersed in the asphalt matrix and the nanocomposite has formed. Rotation Thin Film Oven Test (RTFOT) and Pressure Age Vessel Test (PAV) results indicate that the modified asphalt with 3% organic nano-montmorillonite (OMMT) present better performance of aging resistance. The purpose of this research is to attain ternary asphalt binder with better rheological performance and aging resistance. The ternary modified asphalt binder containing 4% OMMT and 12% TPS by weight were prepared at the laboratory scale using high speed shearing mixer. The rheological properties of OMMT/TPS modified asphalt binders were evaluated before and after aging in present paper. Temperature sweep tests and frequency sweep tests were conducted to characterize the rheological properties of modified asphalt using Dynamic Shear Rheometer (DSR). According to the frequency sweep tests, complex modulus master curves were plotted to analysis the rheological properties. The results indicate that nanoclay/TPS/asphalt ternary binders have more excellent performance of rheological and aging resistance at both high and low temperatures, compared with the virginal bitumen and TPS modified asphalt.

scholarly journals Influence of the Skid Resistance of Ultrathin Wearing Course with Various Types of Asphalt Binders

2020 ◽  
Vol 2020 ◽  
pp. 1-12
Author(s):  
Hongfu Liu ◽  
Teng Guo ◽  
Chenxi Yang ◽  
Yunyong Huang ◽  
Xuelian Li
Keyword(s):  
Asphalt Binder ◽  
Asphalt Mixture ◽  
Asphalt Binders ◽  
Asphalt Pavements ◽  
Skid Resistance ◽  
Modified Asphalt ◽  
Vehicle Loading ◽  
Before And After ◽  
Warm Mix Additives ◽  
Styrene Butadiene

Ultrathin wearing course (UTWC) has been widely applied in both asphalt pavements preventive maintenance and functional overlay. This study’s objective is to evaluate the influence of different modified asphalt binders with warm mix additives on the skid resistance of UTWC and to reveal the attenuation law of skid resistance of UTWC. Three types of modified asphalt binders (Styrene-Butadiene-Styrene- (SBS-) modified asphalt, Acrylester Rubber- (AR-) modified asphalt, and SinoTPS-modified asphalt) and sasobit warm mix asphalt additive were selected to prepare asphalt mixtures. The Model Mobile Load Simulator 3 (MMLS3) was used to simulate repeated vehicle loading and abrasion. The British Pendulum Number (BPN) and Mean Texture Depth (MTD) were chosen to evaluate the skid resistance of the UTWC. The Analysis of Range (ANOR) and Analysis of Variance (ANOVA) were used to verify the significance of asphalt binder on the antiskid performance of the UTWC. ANOR and ANOVA show that the influence of different modified asphalt binders on the skid resistance of the UTWC is significant. The SinoTPS modified asphalt mixture can maintain high texture roughness before and after abrasion, providing excellent and durable skid resistance. The influence of the addition of a warm mixing additive on the skid resistance of UTWC is not significant, and changes in microtexture mainly reflect its impact on antiskid performance. The decay curve of three modified asphalt binders of the skid resistance of the UTWC can be well fitted into an exponential function. The conclusion will play an essential role in selecting the asphalt binder in a UTWC to improve the antiskid performance.

Near-field scanning optical microscopy

1986 ◽  
Vol 44 ◽  
pp. 642-643
Author(s):  
E. Betzig ◽  
A. Harootunian ◽  
M. Isaacson ◽  
A. Lewis
Keyword(s):  
Near Field ◽  
Optical Microscope ◽  
Visible Radiation ◽  
Field Methods ◽  
Optical Elements ◽  
Optical Region ◽  
Order Of Magnitude ◽  
Nondestructive Imaging ◽  
Scanning Optical Microscopy ◽  
Near Field Scanning

In general, conventional methods of optical imaging are limited in spatial resolution by either the wavelength of the radiation used or by the aberrations of the optical elements. This is true whether one uses a scanning probe or a fixed beam method. The reason for the wavelength limit of resolution is due to the far field methods of producing or detecting the radiation. If one resorts to restricting our probes to the near field optical region, then the possibility exists of obtaining spatial resolutions more than an order of magnitude smaller than the optical wavelength of the radiation used. In this paper, we will describe the principles underlying such "near field" imaging and present some preliminary results from a near field scanning optical microscope (NS0M) that uses visible radiation and is capable of resolutions comparable to an SEM. The advantage of such a technique is the possibility of completely nondestructive imaging in air at spatial resolutions of about 50nm.

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