Methods to evaluate intermediate temperature properties of asphalt mixtures by the semi-circular bending (SCB) test

2021 ◽  
pp. 1-13
Author(s):  
Faramarz Safazadeh ◽  
Pedro Romero ◽  
Abu Sufian Mohammad Asib ◽  
Kevin VanFrank
Keyword(s):  
Asphalt Mixtures ◽  
Intermediate Temperature ◽  
Scb Test

scholarly journals Fracture Behavior Analysis of Semi-Circular Bending Test

2019 ◽  
Vol 271 ◽  
pp. 03007
Author(s):  
David Renteria ◽  
Shadi Saadeh ◽  
Enad Mahmoud
Keyword(s):  
Fracture Behavior ◽  
Asphalt Mixture ◽  
Asphalt Mixtures ◽  
Bending Test ◽  
Random Generation ◽  
Crack Initiation And Propagation ◽  
Air Voids ◽  
Generation Technique ◽  
Initiation And Propagation ◽  
Scb Test

The objective of this paper is to investigate the effect of air voids on the fracture properties of asphalt mixtures using SCB test in Discrete Element Method (DEM). Superpave and Coarse Matrix High Binder (CMHB) mixtures gradation were used to generate the percentages of aggregate, mastic, and air voids within the specimens. Aggregates and air voids were randomly generated for each asphalt mixture case. Model results illustrate that the crack initiation and propagation is controlled by the location of the aggregate particles and air voids in the mixture. Additionally, the absence of air voids above the tip of the notch increases the stiffness of the sample and increase its resistance to failure. The novelty of using DEM and the random generation technique for generating numerical specimens proved to be a useful approach in investigating the properties of the mastic, aggregate and interface as they relate to fracture of asphalt mixtures.

Relationship between Rheological Indices and Cracking Performance of Virgin, Recycled, and Rejuvenated Asphalt Binders and Mixtures

2021 ◽  
pp. 036119812110074
Author(s):  
Fawaz Kaseer ◽  
Amy Epps Martin ◽  
Edith Arámbula-Mercado
Keyword(s):  
Asphalt Mixture ◽  
Asphalt Mixtures ◽  
Intermediate Temperature ◽  
Index Test ◽  
Crossover Temperature ◽  
Aging Condition ◽  
Cracking Performance ◽  
R Value ◽  
Rheological Indices

Long-term cracking performance of asphalt mixtures is heavily influenced by asphalt binder rheology, and changes in binder stiffness, ductility, and aging condition significantly affect the cracking resistance of the corresponding asphalt mixture. This study evaluated the effectiveness of several common and recently developed binder rheological indices in capturing the effects of binder performance grade (PG) and source, recycled binder content, recycling agent (rejuvenator) dose, and long-term aging. These binder rheological indices included the Superpave intermediate-temperature PG (PGI), the Glover-Rowe (G-R) parameter, the crossover temperature (Tδ = 45°), the rheological index (R-value), and ΔTc. This study also directly compared the binder rheological indices with the cracking performance of corresponding asphalt mixtures to explore possible correlations and their robustness. Asphalt mixture cracking performance was evaluated using the Illinois Flexibility Index Test (I-FIT) for intermediate-temperature cracking, and the disk-shaped compact tension (DCT) test and the uniaxial thermal stress and strain test (UTSST) for low-temperature cracking. Results indicated that all the binder rheological indices (except PGI) consistently captured the effects of binder blend composition and proportions and aging condition, with a few exceptions. Results also showed that the G-R parameter, the crossover temperature (Tδ = 45°), and ΔTc had the best correlation to asphalt mixture and field core cracking performance as compared with other rheological indices (PGI and R-value), with ΔTc demonstrating the overall best correlation to mixture cracking performance.

Low Temperature Cracking Evaluation of Asphalt Rubber Mixtures Using Semi-Circular Bending Test

2011 ◽  
Vol 243-249 ◽  
pp. 4201-4206 ◽  
Author(s):  
Jing Hui Liu
Keyword(s):  
Low Temperature ◽  
Asphalt Concrete ◽  
Asphalt Mixtures ◽  
Bending Test ◽  
Asphalt Pavements ◽  
Dry Process ◽  
Wet Process ◽  
Asphalt Rubber ◽  
Scb Test ◽  
Low Temperature Cracking

Low temperature cracking is the main distress in asphalt pavements in winter. As asphalt rubber course is increasing, there is no standard method to characterize the resistance to cracking of asphalt rubber mixtures. This paper investigates the use of a Semi Circular Bend (SCB) test as a candidate for a low-temperature cracking specification. Based on the SCB test, this paper presents the findings of a laboratory study that aimed to evaluate the effects of recycled tire rubber on the Low temperature cracking properties of asphalt mixtures. Three mix types, a conventional hot-mix asphalt concrete, a dry process rubber modified asphalt concrete, and a wet process asphalt-rubber asphalt concrete, were included in the investigation. It is found that the asphalt mixtures produced by the wet process showed much better low temperature crack resistance, the binder effect modified by rubber was significant.

Binder composition and intermediate temperature cracking performance of asphalt mixtures containing RAS

2015 ◽  
Vol 16 (sup2) ◽  
pp. 275-295 ◽  
Author(s):  
Samuel B. Cooper ◽  
Ioan Negulescu ◽  
Sreelatha S. Balamurugan ◽  
Louay Mohammad ◽  
William H. Daly
Keyword(s):  
Asphalt Mixtures ◽  
Intermediate Temperature ◽  
Cracking Performance ◽  
Binder Composition

Relationships among Chemistry, Rheology, and Fracture/Fatigue Performance of Recovered Asphalt Binders and Asphalt Mixtures Containing Reclaimed Asphalt Pavement

2020 ◽  
Vol 2674 (10) ◽  
pp. 927-938
Author(s):  
Peyman Barghabany ◽  
Wei Cao ◽  
Louay N. Mohammad ◽  
Samuel B. Cooper ◽  
Samuel B. Cooper
Keyword(s):  
Asphalt Pavement ◽  
Asphalt Binder ◽  
Asphalt Mixture ◽  
Asphalt Mixtures ◽  
Intermediate Temperature ◽  
Asphalt Binders ◽  
Rheological Parameters ◽  
Cracking Resistance ◽  
Reclaimed Asphalt ◽  
Four Point Bending

Because of limited amounts of natural resources, reclaimed asphalt pavement (RAP) has gained popularity in the asphalt pavement industry to meet sustainability requirements in asphalt pavement. Concerns have been raised in relation to the intermediate temperature cracking performance of asphalt mixtures containing RAP. The objective of this study was to evaluate the intermediate temperature cracking resistance of asphalt mixtures and recovered asphalt binders containing RAP. Seven plant-produced asphalt mixtures from three transportation agencies with various RAP contents and the extracted asphalt binders were evaluated with respect to intermediate temperature cracking resistance. Asphalt binder experiments included chemical and rheological characterization of recovered asphalt binders. Chemical characterization consisted of Fourier transform infrared spectroscopy and saturates/aromatics/resins/asphaltenes component analysis. Linear amplitude sweep and time sweep tests were also performed to characterize the rheological properties of asphalt binders. Asphalt mixture experiments included four-point bending beam fatigue and semi-circular bend tests. Results indicated that, as expected, asphalt mixtures with high RAP contents resulted in asphalt binders and mixtures with reduced cracking resistance. Relationships between the asphalt binder chemical and rheological parameters and asphalt mixture cracking resistance were also investigated. Asphalt binder rheological and chemical parameters were well correlated. Asphalt binder rheological parameters showed reasonable to strong relationships with the four-point bending beam fatigue test result. The work presented in this paper is part of FHWA Transportation Pooled Fund Project TPF-5(294) “Develop Mix Design and Analysis Procedure for Asphalt Mixtures Containing High RAP and/or RAS Contents.”

Effect of Testing Configuration in Semi-Circular Bending Fracture of Asphalt Mixtures: Experiments and Statistical Analyses

2019 ◽  
Vol 2673 (5) ◽  
pp. 320-328 ◽  
Author(s):  
Gabriel Nsengiyumva ◽  
Yong-Rak Kim
Keyword(s):  
Fracture Behavior ◽  
Peak Load ◽  
Test Methods ◽  
Asphalt Mixtures ◽  
Statistical Analyses ◽  
Test Results ◽  
Scb Test ◽  
Transportation Agencies ◽  
Bending Fracture ◽  
Flexibility Index

The semi-circular bending (SCB) test is a simple, efficient, and easily applicable method in the pavement community to characterize fracture behavior. This makes it widely used as a quality control (QC) and quality assurance (QA) approach at several transportation agencies. However, public–private testing laboratories have implemented SCB test methods using different load-support fixture conditions with an insufficient understanding of how the conditions affect the results and testing variability. This could be particularly problematic when using SCB test results obtained from different load-support fixtures as QC–QA (or pass/fail) purposes. This study investigated the effect of SCB testing configurations on test results and their variability by conducting tests using six different load-support fixtures. Several fracture-related indicators such as fracture energy, flexibility index, peak load, and the coefficient of the cracking index resulting from the six different load-support fixtures were compared. Test results and statistical analyses showed that SCB tests generally showed repeatable results, whereas load-support fixtures can affect test results and their repeatability, thus care should be taken when choosing a testing fixture. The addition of roller springs generally increased the variability of the test results. It appears that the mid-span jig was detrimental to testing repeatability, and friction at the support should be avoided because it can erroneously increase fracture resistance with a higher variability.

Asphalt mixtures containing RAS and/or RAP: relationships amongst binder composition analysis and mixture intermediate temperature cracking performance

2016 ◽  
Vol 18 (sup1) ◽  
pp. 209-234 ◽  
Author(s):  
Samuel B. Cooper ◽  
Ioan Negulescu ◽  
Sreelatha S. Balamurugan ◽  
Louay Mohammad ◽  
William H. Daly ◽  
...  
Keyword(s):  
Asphalt Mixtures ◽  
Intermediate Temperature ◽  
Composition Analysis ◽  
Cracking Performance ◽  
Binder Composition

scholarly journals Influence of Laboratory Long-Term Aging on Selected Fracture Parameters of Asphalt Mixtures

Materials ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 811
Author(s):  
Pavla Vacková ◽  
Jan Valentin ◽  
Majda Belhaj
Keyword(s):  
Asphalt Mixtures ◽  
Bending Test ◽  
Cracking Behavior ◽  
Reclaimed Asphalt ◽  
Fracture Properties ◽  
Three Point Bending ◽  
Complex Information ◽  
Scb Test ◽  
Fracture Work

The paper presents the influence of laboratory aging simulation on fracture properties determined on 150 variants of asphalt mixtures. The fracture properties were determined by two different test approaches—semi-circular bending test (SCB test) and three-point bending test on beam specimens (3-PB test). The aging was simulated according to one of the methods defined in EN 12697-52 (storage of test specimens in chamber at temperature of 85 °C for 5 days). The evaluated group of variants covered asphalt mixtures for all road layers. The group was further divided according to used bituminous binder (unmodified vs. modified) and reclaimed asphalt content. The results showed that strength parameters (flexural strength and fracture toughness) increase with aging. It further shows that fracture work provides more complex information about the cracking behavior. For the aging indexes, it was found that for mixtures with modified binders and mixtures which did not contain reclaimed asphalt (RA), the values were higher. The aging indexes for fracture work showed different results for both performed tests.

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