scholarly journals Application of Acoustic Emissions Technique in Assessment of Cracking Performance of Asphalt Pavement Materials

2021 ◽  
Author(s):  
Behzad Behnia
Keyword(s):  
Low Temperature ◽  
Acoustic Emissions ◽  
Asphalt Binders ◽  
Asphalt Pavements ◽  
Oxidative Aging ◽  
Aged Asphalt ◽  
Asphalt Materials ◽  
Cracking Performance ◽  
Low Temperature Cracking ◽  
Viable Approach

This chapter focuses on various applications of acoustic emissions (AE) technique in evaluation of cracking in asphalt pavements including (1) assessment of low-temperature cracking of asphalt binders and mixtures and (2) quantitative characterization of rejuvenators’ efficiency in restoring aged asphalt pavements to their crack-resistant state. The AE-based embrittlement temperature results of 24 different asphalt materials consisting of eight different binders, each at three oxidative aging levels are presented. Results show that embrittlement temperatures correlated well with corresponding bending beam rheometer (BBR-based) critical cracking temperatures with R2 = 0.85. This chapter also presents application of AE for evaluation of rejuvenators’ efficiency on asphalt materials at various oxidative aging levels. The Geiger’s iterative source location method was employed to accurately determine embrittlement temperatures throughout the thickness of rejuvenator-treated asphalt samples. Results showed that the low temperature cracking properties of oxidative aged materials after 2 weeks of dwell time of rejuvenator have been recuperated. Moreover, it was observed that cracking characteristics of aged asphalt 6–8 weeks after applying rejuvenator far exceeded that of the virgin materials. The promising results suggest that the AE technique can be considered as a viable approach for the assessment of low temperature behavior of asphalt pavements.

Evaluation of Carbon Nanotubes Asphalt Modification Using the Superpave Criteria

2021 ◽  
Vol 902 ◽  
pp. 135-143
Author(s):  
Mohammad Ali Khasawneh ◽  
Khalid Ghuzlan ◽  
Nada Bani Melhem
Keyword(s):  
Carbon Nanotubes ◽  
Low Temperature ◽  
Rheological Properties ◽  
Asphalt Binder ◽  
Fatigue Cracking ◽  
Asphalt Binders ◽  
Asphalt Pavements ◽  
Low Temperature Cracking ◽  
Asphalt Modification ◽  
Rotational Viscosity

Rutting, fatigue cracking and low temperature cracking are the most important distresses in asphalt pavements as a result of changes in rheological properties of asphalt binder. Many types of modifiers were used to enhance asphalt behavior at both low and high temperatures. In this study, carbon nanotubes (CNT) were used as one of many nanomaterials that take a large attention in the latest research related to asphalt modification against different types of distresses. Effect of CNT on rheological properties of asphalt binder was investigated by testing unmodified and CNT modified asphalt binders using two of Superpave devices: Dynamic Shear Rheometer (DSR) and Bending Beam Rheometer (BBR). Penetration, softening point, flash point and rotational viscosity (RV) tests were carried out as well. CNT was added in 0.1%, 0.5% and 1% by weight of asphalt binder. It was found that adding CNT in 0.5% and 1% increase stiffness of asphalt and consequently asphalt pavement rutting resistance. On the other hand, this increase in stiffness affected pavement behavior adversely which is not desirable for fatigue and low temperature cracking. However, Superpave specifications were still satisfied and asphalt binder’s relaxation properties were improved upon CNT modification. It was eventually found that 0.5% of CNT is the optimum percentage for the best performance.

scholarly journals Study on Low-Temperature Cracking Performance of Asphalt under Heat and Light Together Conditions

Materials ◽  
2020 ◽  
Vol 13 (7) ◽  
pp. 1541 ◽  
Author(s):  
Limin Li ◽  
Zhaoyang Guo ◽  
Longfei Ran ◽  
Jiewen Zhang
Keyword(s):  
Low Temperature ◽  
Early Stage ◽  
Asphalt Pavement ◽  
Climatic Conditions ◽  
Asphalt Binders ◽  
Composition Analysis ◽  
Cracking Resistance ◽  
Modified Asphalt ◽  
Cracking Performance ◽  
Low Temperature Cracking

The low-temperature cracking performance of asphalt is considered one of the main deteriorations in asphalt pavements. However, there have been few studies on the low-temperature cracking performance of asphalt under heat and light together. Hence, the ductility test, bending beam rheometer (BBR) test, and asphalt composition analysis test are combined to investigate the low-temperature cracking performance under heat and light together based on the climatic conditions of China. The styrene–butadiene–styrene block copolymer (SBS)-modified asphalt binders were prepared with different modifier types and base asphalt in this research. The results show that the low-temperature cracking resistance of asphalt reduces under heat and light together. It is obviously reduced at the early stage, and it becomes worse with the increase of the aging time, temperature, and ultraviolet (UV) intensity. The asphalt composition has a significant impact on its low-temperature cracking performance, and the SBS modifier can improve the low-temperature cracking resistance of asphalt. The rational selection of base asphalt and modifier can improve the low-temperature cracking performance of asphalt. Under heat and light together, whether base asphalt or modified asphalt, the change trends of their ductility and component content are similar. Therefore, to improve the anti-cracking ability of the asphalt pavement, it is suggested to use the ductility of asphalt aged by heat and light together for 15 days as the evaluation index of the low-temperature cracking performance of asphalt, and asphalt should be selected according to the temperature and UV intensity of the asphalt pavement use area.

Influence Analysis of Performance on Sasobit Warm Mix Asphalt with Salinity

2014 ◽  
Vol 490-491 ◽  
pp. 138-141
Author(s):  
Kun Wang ◽  
Jing Ya Chen ◽  
Xiang Qu
Keyword(s):  
Low Temperature ◽  
Environmental Benefits ◽  
Fatigue Performance ◽  
Test Results ◽  
Temperature Performance ◽  
Cracking Performance ◽  
Low Temperature Cracking ◽  
Short And Long Term ◽  
Analysis Of Performance

Sasobit warm mix drainage asphalt pavement has become increasingly popular due to its environmental benefits and comfortable using effect. However, test results show that its low-temperature and anti-fatigue performance have a certain degree of reduced. To improve the performance of asphalt four different doses (1%, 3%, 5% and 7%) of salt are added to the Sasobit asphalt. Laboratory tests were used to simulate short and long term aging asphalt in the process of construction and using pavement. A series of binder tests including bending beam rheometer (BBR), dynamic shear rheometer (DSR) and Brookfield viscosity tests were conducted. Results show an increase of rutting performance for warm mix binders with Sasobit while asphalt with salt has similar high temperature performance to original asphalt. Unlike Sasobit which has a decrease of cracking performance for asphalt at low-temperature, salinity can greatly improve the Low-temperature performance. And the low-temperature cracking performance and anti-fatigue performance presents a tendency of climbing up first and then declining with the increase of salinity. The figure of viscosity-temperature curve shows that the optimum of salinity is 5%.Further more, asphalt with Sasobit and salt can gain better performance and same mixing and compaction effect in lower 20°C than hot mix asphalt without it.

Behaviour of recycled asphalt pavements at low temperatures

1991 ◽  
Vol 18 (3) ◽  
pp. 428-435 ◽  
Author(s):  
M. Sargious ◽  
N. Mushule
Keyword(s):  
Finite Element ◽  
Low Temperature ◽  
Thermal Stresses ◽  
Asphalt Pavements ◽  
Recycled Asphalt ◽  
Expected Performance ◽  
Different Types ◽  
Low Temperature Cracking ◽  
Proper Comparison ◽  
Better Than

This paper summarizes the results of a study conducted to evaluate the behaviour of recycled asphalt pavements with respect to low-temperature cracking. For this purpose, a recycled mix consisting of 45.2% reclaimed materials and 54.8% virgin materials as well as a virgin control mix were used in the research program. In the design of both mixes, their initial properties were kept as close as possible to each other to allow for a proper comparison between recycled and virgin asphalt pavements. Using mix properties that were determined experimentally in the laboratory, thermal stresses resulted from drop in temperature and the expected cracking temperatures were determined for both mixes. An experimental analysis based on laboratory tests that consider the pavement properties only as well as a more complete theoretical analysis based on a finite element computer program known as FETAB were included in this study. The program incorporates subgrade parameters, as well as pavement properties and thickness. Using these variables as inputs to the program, the expected performance of recycled and virgin asphalt pavements of various thicknesses and resting on different types of subgrade, with respect to low-temperature cracking, was studied. The results of the study indicated that recycled asphalt pavements would perform better than virgin asphalt pavements of similar initial properties. Key words: asphalt, finite element, low-temperature cracking, reclaimed, recycled, thermal stresses.

Effect of Hydrated Lime on Long-Term Oxidative Aging Characteristics of Asphalt

2002 ◽  
Vol 1810 (1) ◽  
pp. 17-24 ◽  
Author(s):  
Shin-Che Huang ◽  
J. Claine Petersen ◽  
Raymond Robertson ◽  
Jan F. Branthaver
Keyword(s):  
Phase Angle ◽  
Fatigue Cracking ◽  
Hydrated Lime ◽  
Age Hardening ◽  
Asphalt Binders ◽  
Asphalt Pavements ◽  
Initial Stiffness ◽  
Oxidative Aging ◽  
Useful Lifetime

An experiment involving neat asphalts AAD-1, ABD, and their mixtures with two different grades of hydrated lime was conducted to investigate the effect of lime on the long-term aging characteristics of asphalt binders. Rheological properties of unaged and aged asphalt-lime mixtures were measured with a dynamic shear rheometer at 25°C (77°F) and 60°C (140°F). The addition of hydrated lime to one asphalt (AAD-1) effectively reduced oxidative age hardening. In addition, the phase angle reached the same value as aging time reached after approximately 800 h at 60°C in the pressure-aging vessel for AAD-1 and its mixtures with lime. After 800 h of aging, the phase angle was greater for the limetreated asphalt than for the untreated asphalt, and it continued to decrease at a slower rate. This result indicates that the addition of lime to this asphalt increases the initial stiffness of the binder, but, more importantly, it preserves elasticity during long-term oxidative aging. Thus, for this asphalt, at a level of oxidation typical of pavements, limetreated and untreated asphalts arrived at the same viscosity with time, but the lime-treated asphalt had better viscous flow properties than the untreated asphalt. It could then be predicted that the aged, lime-treated asphalt would be more resistant to fatigue cracking. The other asphalt tested (ABD) did not exhibit substantial effects of lime on the rate of oxidative age hardening. This highly compatible, low-asphaltene asphalt is not typical of most paving asphalts. Because hydrated lime has been shown to reduce oxidative age hardening both in the laboratory and during the first few years in the pavement, adding hydrated lime should extend the useful lifetime of most asphalt pavements.

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