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.

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.

Fatigue Tolerance of Aged Asphalt Binders Modified with Softeners

2021 ◽  
pp. 036119812110255
Author(s):  
Javier J. García Mainieri ◽  
Punit Singhvi ◽  
Hasan Ozer ◽  
Brajendra K. Sharma ◽  
Imad L. Al-Qadi
Keyword(s):  
Shear Stress ◽  
Heavy Traffic ◽  
Asphalt Binder ◽  
Fatigue Cracking ◽  
Data Interpretation ◽  
Complex Stress ◽  
Current Data ◽  
Asphalt Binders ◽  
Failure Patterns ◽  
Peak Shear Stress

Fatigue cracking caused by repeated heavy traffic loading is a critical distress in asphalt concrete pavements and is significantly affected by the selected binder. In recent years, the growing use of recycled asphalt materials has increased the need for the production of softer asphalt binder. Various modifiers/additives are marketed to adjust the grade and/or enhance the binder performance at high and low temperatures. The modifiers are expected to alter the rheological and chemical characteristics of binders and, therefore, their performance. In this study, the damage characteristics of modified and unmodified binders, at standard long-term and extended aging conditions, were tested using the linear amplitude sweep (LAS) test. Current data-interpretation methods for LAS measurements (including AASHTO TP 101-12, T 391-20, and recent literature) showed inconsistent results for modified binders. An alternative method to interpret LAS results was developed in this study. The method considers the data until peak shear-stress is reached because complex stress states and failure patterns are observed in the specimens after that point. The proposed parameter (Δ| G*|peak τ) quantifies the reduction in complex shear modulus measured at the peak shear-stress. The parameter successfully captures the effect of aging and modification of binders.

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.

Dynamic Properties of Asphalt Binders Containing Fiber Modifiers

2010 ◽  
Vol 97-101 ◽  
pp. 724-727 ◽  
Author(s):  
Qun Shan Ye ◽  
Shao Peng Wu
Keyword(s):  
Shear Test ◽  
Dynamic Properties ◽  
Asphalt Binder ◽  
Asphalt Binders ◽  
Test Results ◽  
Modified Asphalt ◽  
Rate Versus ◽  
Complex Shear ◽  
Creep Modulus ◽  
Phase Angles

Dynamic shear test and creep shear test were employed to investigate the dynamic properties of various fiber modified asphalt binders with the fiber content of 1.0%. The test results indicate that complex shear modulus of asphalt binders containing fibers are increased while the phase angles are decreased greatly, which implies that the asphalt binder is reinforced by the addition of fibers and the elastic property of asphalt binder is improved significantly, especially at high frequency levels. The total strain during loading period and the residual strain after the creep shear test of asphalt binders are reduced greatly by the addition of fibers. Furthermore, the creep modulus of fiber modified asphalt binders is increased and the development rate versus loading time of creep modulus is decreased.

scholarly journals Fatigue Resistance and Cracking Mechanism of Semi-Flexible Pavement Mixture

Materials ◽  
2021 ◽  
Vol 14 (18) ◽  
pp. 5277
Author(s):  
Shiqi Wang ◽  
Huanyun Zhou ◽  
Xianhua Chen ◽  
Minghui Gong ◽  
Jinxiang Hong ◽  
...  
Keyword(s):  
Low Temperature ◽  
Fatigue Resistance ◽  
Stress Ratio ◽  
Asphalt Binder ◽  
Asphalt Mixture ◽  
Fatigue Cracking ◽  
Flexible Pavement ◽  
The Poor ◽  
Grouting Material ◽  
Cracking Mechanism

Semi-flexible pavement (SFP) is widely used in recent years because of its good rutting resistance, but it is easy to crack under traffic loads. A large number of studies are aimed at improving its crack resistance. However, the understanding of its fatigue resistance and fatigue-cracking mechanism is limited. Therefore, the semi-circular bending (SCB) fatigue test is used to evaluate the fatigue resistance of the SFP mixture. SCB fatigue tests under different temperature values and stress ratio were used to characterize the fatigue life of the SFP mixture, and its laboratory fatigue prediction model was established. The distribution of various phases of the SFP mixture in the fracture surface was analyzed by digital image processing technology, and its fatigue cracking mechanism was analyzed. The results show that the SFP mixture has better fatigue resistance under low temperature and low stress ratio, while its fatigue resistance under other environmental and load conditions is worse than that of asphalt mixture. The main reason for the poor fatigue resistance of the SFP mixture is the poor deformation capacity and low strength of grouting materials. Furthermore, the performance difference between grouting material and the asphalt binder is large, which leads to the difference of fatigue cracking mechanism of the SFP mixture under different conditions. Under the fatigue load, the weak position of the SFP mixture at a low temperature is asphalt binder and its interface with other materials, while at medium and high temperatures, the weak position of the SFP mixture is inside the grouting material. The research provides a basis for the calculation of the service life of the SFP structure, provides a reference for the improvement direction of the SFP mixture composition and internal structure.

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.

scholarly journals Performance Evaluation of Crumb Rubber Asphalt Modified with Silicone-Based Warm Mix Additives

2020 ◽  
Vol 2020 ◽  
pp. 1-17 ◽  
Author(s):  
Nonde Lushinga ◽  
Liping Cao ◽  
Zejiao Dong ◽  
Chen Yang ◽  
Cyriaque O. Assogba
Keyword(s):  
Asphalt Binder ◽  
Fatigue Cracking ◽  
Crumb Rubber ◽  
Warm Mix Asphalt ◽  
Asphalt Binders ◽  
Water Repellent ◽  
Creep Recovery ◽  
Viscoelastic Continuum Damage ◽  
Warm Mix Additives ◽  
Different Temperatures

This research was conducted to elucidate better understanding of the performance of crumb rubber asphalt modified with silicone-based warm mix additives. Two different silicone-based warm mix asphalt (WMA) additives (herein Tego XP and Addibit) were used to prepare crumb rubber modified (CRM) warm mix asphalt binders. The viscosity of these CRM binders was measured at different temperatures and shearing rates. Furthermore, softening point and penetration tests, Multiple Stress Creep Recovery (MSCR), Time Sweep (TS), Atomic Force Microscopy (AFM), Frequency sweep (FS), and Fourier Transform Infrared (FTIR) tests were also conducted on prepared samples. Based on these robust and rigorous laboratory experiments, it was established that viscosity of CRM binders was reduced by addition of Tego XP and Addibit WMA additives. However, WMA additives had different influence on rheological properties of the binder. CRM binder with Tego XP improved resistance to rutting of the binders but would degrade the fatigue performance. On the contrary, viscoelastic continuum damage (VECD) model results and those of phase angle approach revealed that the binder with Addibit improved resistance to fatigue cracking of the binders but had no adverse effects on high temperature rutting performance. FTIR test results established a presence of polydimethylsiloxane (PDMS) in CRM binders with Tego XP and Addibit. PDMS is a well-known hydrophobic organic and inorganic polymer that is water repellent; therefore, binders containing these silicone-based warm mix additives could be beneficial in resisting moisture damage in asphalt binders and mixtures. Morphology of CRM binders with and without WMA revealed good distribution of the rubber particles in asphalt binder matrix. Further addition of WMA increased surface roughness of the binder, which can be correlated to changes in microstructure properties of the binder. Therefore, the study concluded that addition of Tego XP and Addibit reduces viscosity and improves mechanical properties of the asphalt binder.

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 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.

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