scholarly journals Study on the Effect of Regeneration Agent on the Viscosity Properties of Aged Asphalt

Materials ◽  
2022 ◽  
Vol 15 (1) ◽  
pp. 380
Author(s):  
Jiangang Yang ◽  
Luhua Luo ◽  
Jie Gao ◽  
Jing Xu ◽  
Chengping He
Keyword(s):  
Asphalt Pavement ◽  
Gel Permeation Chromatography ◽  
Asphalt Mixtures ◽  
Utilization Rate ◽  
Recycled Asphalt ◽  
Characteristic Functional ◽  
Positive Role ◽  
Force Microscopy ◽  
Needle Penetration ◽  
Aged Asphalt

China’s highway asphalt pavement has entered the stage of major repair, and improving the utilization rate of recycled asphalt pavement (RAP) is the main issue. The key link affecting the performance of recycled asphalt mixtures is the regeneration of aged asphalt, and the effect of the regenerant dosing on the high-temperature performance and viscosity of aged asphalt is the main content to be studied in this research. The aging behavior of asphalt seriously affects the roadworthiness of asphalt mixtures. In this study, we investigated the effect of changes in the microscopic properties of the aged asphalt on its viscosity properties during regeneration using gel permeation chromatography (GPC), Fourier-transform infrared spectroscopy (FTIR), and atomic force microscopy (AFM) as well as Brinell viscosity tests. This study simulated asphalt aging by the RTFOT test, and then we obtained an aged asphalt with a needle penetration of 30. We prepared different regenerated asphalts by adding regeneration agent with doses of 2%, 4%, and 6% to the aged asphalt. The results showed that the regeneration agent could effectively reduce the viscosity of the aged asphalt, which can play a positive role in improving the construction and ease of the aged asphalt. Rejuvenation agents affected the aging asphalt sulfoxide and carbon group indices. Moreover, rejuvenation agents can also significantly reduce the intensities of their characteristic functional group indices. The results of the AFM test showed that the increase in the dose of regeneration agent increased the number of the asphalt bee-like structures and decreased the area of individual bee-like structures. The results of the GPC test were consistent with the results of the AFM test, and the increase in the dose of regeneration agent reduced the asphalt macromolecule content. The viscosity properties and microstructure of the aged asphalt changed positively after the addition of the regeneration agent, indicating that the regeneration agent had a degrading and diluting effect on macromolecules.

scholarly journals A Review on the Durability of Recycled Asphalt Mixtures Embraced with Rejuvenators

2021 ◽  
Vol 13 (16) ◽  
pp. 8970
Author(s):  
Zaid Hazim Al-Saffar ◽  
Haryati Yaacob ◽  
Herda Yati Katman ◽  
Mohd Khairul Idham Mohd Satar ◽  
Munder Bilema ◽  
...  
Keyword(s):  
Asphalt Pavement ◽  
Climatic Conditions ◽  
Asphalt Mixtures ◽  
Reclaimed Asphalt Pavement ◽  
Extensive Literature ◽  
Recycled Asphalt ◽  
Reclaimed Asphalt ◽  
Traffic Loads ◽  
Aged Asphalt ◽  
Future Challenges

Reclaimed asphalt pavement (RAP) has received much attention recently due to its increased use in hot mix asphalt (HMA) pavements to enhance pavement sustainability. The use of aged asphalt in RAP, which is highly oxidised and has lost its properties due to exposure to traffic loads and climatic conditions throughout its lifespan, can cause asphalt mixtures to stiffen and embrittle, thus negatively affecting the behaviour of asphalt mixtures. This issue may be resolved by including rejuvenating agents that can restore both physical and rheological properties of aged asphalt by increasing maltene fractions and decreasing asphaltene. However, the high restoration capacity of any kind of rejuvenating agent does not assure the durability of restored aged asphalt. This study explored the performance and durability of rejuvenated asphalt mixtures embedded with several types of rejuvenators identified from the extensive literature review. The study serves as a significant reference to predict future challenges in rejuvenating aged asphalt.

scholarly journals Quantitative Analysis of the Blending Degree of Virgin and RAP Binders in Recycled Asphalt Mixtures with a High RAP Content

2018 ◽  
Vol 8 (12) ◽  
pp. 2668 ◽  
Author(s):  
Zhen Yang ◽  
Guoyi Zhuang ◽  
Xiaoshu Wei ◽  
Jintao Wei ◽  
Huayang Yu ◽  
...  
Keyword(s):  
Asphalt Pavement ◽  
Asphalt Mixtures ◽  
Reclaimed Asphalt Pavement ◽  
Structural Index ◽  
Comprehensive Understanding ◽  
Recycled Asphalt ◽  
Reclaimed Asphalt ◽  
Standard Curve ◽  
Study Results ◽  
Mineral Additives

Recycled asphalt mixtures (RAM), which are prepared by blending reclaimed asphalt pavement (RAP), virgin bitumen and mineral additives, provide a variety of advantages, including resource recycling, reductions in costs, and reduced negative environmental impacts. However, multiple agencies have expressed concerns about the utilization ratio of RAP; thus, a comprehensive understanding of the blending degree of virgin and RAP binders in RAM would be significantly helpful for promoting the application of RAP. This study aims to quantitatively analyze the blending degree of virgin and RAP binders in RAM with high RAP contents. Carboxyl-terminated butadiene acrylonitrile (CTBN) was utilized as a tracer to mark the virgin bitumen; in addition, Fourier transform infrared (FTIR) spectroscopy was used to develop the structural index of CTBN (ICTBN). By establishing the standard curve between ICTBN and the CTBN content, the blending degree of virgin and RAP binders at different locations within RAM can be determined quantitatively. The study results indicate that the RAP binder was completely blended with the virgin bitumen in the outer RAP layer. However, the blending degree decreased with an increase in the RAP depth, and the blending degree in the inner RAP layer was only approximately half that which was found in the case of complete blending.

Mechanistic and Volumetric Properties of Asphalt Mixtures with Recycled Asphalt Pavement

2005 ◽  
Vol 1929 (1) ◽  
pp. 28-36 ◽  
Author(s):  
Jo Sias Daniel ◽  
Aaron Lachance
Keyword(s):  
Dynamic Modulus ◽  
Creep Compliance ◽  
Asphalt Pavement ◽  
Superposition Principle ◽  
Asphalt Mixtures ◽  
Volumetric Properties ◽  
Recycled Asphalt Pavement ◽  
Recycled Asphalt ◽  
Creep Flow ◽  
Tension And Compression

This research examines how the addition of recycled asphalt pavement (RAP) changes the volumetric and mechanistic properties of asphalt mixtures. A Superpave® 19-mm mixture containing 0% RAP was the control for evaluating properties of mixes containing 15%, 25%, and 40% RAP. Two types of RAP were evaluated: a processed RAP and an unprocessed RAP (grindings). Testing included dynamic modulus in tension and compression, creep compliance in compression, and creep flow in compression. Dynamic modulus and creep compliance master curves were constructed with the use of the time–temperature superposition principle to describe the behavior of each mix over a range of temperatures. The voids in mineral aggregate (VMA) and voids filled with asphalt (VFA) of the RAP mixtures increased at the 25% and 40% levels, and there was also an influence of preheating time on the volumetric properties. The dynamic modulus of the processed RAP mixtures increased from the control to 15% RAP level, but the 25% and 40% RAP mixtures had dynamic modulus curves similar to that of the control mixture in both tension and compression. The creep compliance curves showed similar trends. A combination of gradation, asphalt content, and volumetric properties is likely the cause of these trends.

scholarly journals Potential of Using Imidazoline in Recycled Asphalt Pavement

2019 ◽  
Vol 14 (4) ◽  
pp. 521-542
Author(s):  
Robert Jurczak ◽  
Paweł Mieczkowski ◽  
Bartosz Budziński
Keyword(s):  
Asphalt Concrete ◽  
Asphalt Pavement ◽  
Asphalt Mixtures ◽  
Fatigue Performance ◽  
Recycled Asphalt Pavement ◽  
Recycled Asphalt ◽  
Stiffness Modulus ◽  
Optimum Content ◽  
Environmental Considerations ◽  
Freezing Temperatures

The environmental considerations need to be taken into account in any road resurfacing and upgrading project, for example, by reusing asphalt rubble for production of new pavement courses. Mixtures containing larger amounts of recycled asphalt pavement are improved by adding rejuvenator additives. The tests performed on the recycled asphalt mixtures containing lard imidazoline confirm the suitability of this agent for paving applications. Lard imidazoline was found to improve the stiffness modulus, fatigue performance and resistance to the action of water and freezing temperatures. The parameters obtained at the optimum content of additive complied with the criteria defined for virgin asphalt concrete and other mixtures of that kind.

scholarly journals Towards the Use of Waste Pig Fat as a Novel Potential Bio-Based Rejuvenator for Recycled Asphalt Pavement

Materials ◽  
2020 ◽  
Vol 13 (4) ◽  
pp. 1002
Author(s):  
Nader Nciri ◽  
Taesub Shin ◽  
Namho Kim ◽  
Arnaud Caron ◽  
Hanen Ben Ismail ◽  
...  
Keyword(s):  
Low Temperature ◽  
Asphalt Pavement ◽  
Fatigue Cracking ◽  
Recycled Asphalt ◽  
Excellent Thermal Stability ◽  
Temperature Performance ◽  
Aged Asphalt ◽  
Ft Ir ◽  
Low Temperature Performance ◽  
The Impact

This article presents a novel potential bio-based rejuvenator derived from waste pig fat (WPF) for use in recycled asphalt applications. To achieve this purpose, the impact of different doses waste pig fat (e.g., 0, 3, 6, and 9 wt.% WPF) on the reclaimed asphalt pavement binder (RAP-B) performance is investigated. The unmodified and WPF-modified asphalts are characterized by means of Fourier-transform infrared spectroscopy (FT-IR), thin-layer chromatography–flame ionization detection (TLC-FID), scanning electron microscopy (SEM), atomic force microscopy (AFM), thermogravimetric analysis (TGA), and differential scanning calorimetry (DSC). Physico-rheological properties of asphalt blends are assessed through Brookfield viscometer, softening point, penetration, and dynamic shear rheometer (DSR) tests. TLC-FID data highlighted that incremental WPF addition into RAP-B restored its original balance maltenes-to-asphaltenes ratio; finding which was supported by FT-IR analysis. SEM disclosed that WPF has a great compatibility with the aged asphalt. AFM observations showed that grease treatment induced a decline in surface roughness (i.e., bee structures) and a rise in friction force (i.e., para-phase dimension) of RAP binder. TGA/DSC studies revealed that the bio-modifier not only possesses an excellent thermal stability but also can substantially enhance the binder low-temperature performance. Empirical and DSR tests demonstrated that WPF improved the low-temperature performance grade of RAP-B, reduced its mixing and compaction temperatures, and noticeably boosted its fatigue cracking resistance. The rejuvenation of aged asphalt employing WPF is feasible and can be an ideal approach to recycle both of RAP and waste pig fats.

scholarly journals Investigation on Hamburg Wheel-Tracking Device Stripping Performance Properties of Recycled Hot-Mix Asphalt Mixtures

Materials ◽  
2020 ◽  
Vol 13 (21) ◽  
pp. 4704
Author(s):  
Waqas Rafiq ◽  
Madzlan Bin Napiah ◽  
Muslich Hartadi Sutanto ◽  
Wesam Salah Alaloul ◽  
Zarisha Nadia Binti Zabri ◽  
...  
Keyword(s):  
Hot Mix Asphalt ◽  
Asphalt Pavement ◽  
Asphalt Mixtures ◽  
Asphalt Pavements ◽  
Recycled Asphalt ◽  
Persistent Problem ◽  
Moisture Stability ◽  
Tracking Device ◽  
Wheel Tracking ◽  
Hamburg Wheel Tracking

Moisture damage in hot mix asphalt pavements is a periodic but persistent problem nowadays, even though laboratory testing is performed to identify different moisture-susceptible mixtures. In this study, a Hamburg Wheel Tracking device (HWTD) was used for rutting tests which were conducted on control and a high percentage of recycled asphalt pavement (RAP), i.e., 30%, 50% and 100% of virgin mixtures, under air dry and water-immersed conditions. Similarly, the extracted bitumen from RAP was tested for binder physical properties. Results showed that the asphalt mixtures containing RAP have less rut depth as compared to the control mix both in air dry and immersion conditions and hence showed better anti-rutting properties and moisture stability. Stripping performance of control and RAP containing mixtures was also checked, concluding that the RAP mixture was greatly dependent on the interaction between the binder (virgin plus aged) and aggregates.

Detection of Reclaimed Asphalt Pavement Presence in Asphalt Mixtures Using a Method of Successive Asphalt Binder Extraction

2021 ◽  
Vol 904 ◽  
pp. 458-463
Author(s):  
Jiří Sachr ◽  
Ondrej Dasek ◽  
Petr Hyzl
Keyword(s):  
Asphalt Pavement ◽  
Asphalt Binder ◽  
Asphalt Mixtures ◽  
Reclaimed Asphalt Pavement ◽  
Reclaimed Asphalt ◽  
Needle Penetration ◽  
Successive Extraction ◽  
Complex Shear ◽  
Empirical Tests ◽  
Aged Binder

The work deals with the detection of presence of RAP (reclaimed asphalt pavement) in asphalt mixtures. Information about the presence of RAP in an asphalt layer can be technically advantageous, for example, when planning further recycling of the layer. The method described in the paper can also be used to verify the success of a treatment of an aged binder in RAP, which is dosed in the production of new asphalt mixtures. The asphalt binder was obtained by a method of successive extraction from asphalt mixtures with different RAP content. Basic empirical tests of the asphalt binder (needle penetration and softening point) were chosen to detect the presence of RAP. The complex shear modulus G* was further determined on the extracted binders using a dynamic shear rheometer (DSR).

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