scholarly journals Effect of Cereclor as Rejuvenator to Enhance the Aging Resistance of Reclaimed Asphalt Pavement Binder

Materials ◽  
2020 ◽  
Vol 13 (7) ◽  
pp. 1582 ◽  
Author(s):  
Ghulam Yaseen ◽  
Imran Hafeez
Keyword(s):  
Artificial Aging ◽  
Asphalt Pavement ◽  
Colloidal System ◽  
Reclaimed Asphalt Pavement ◽  
Aging Effects ◽  
Reclaimed Asphalt ◽  
Long Run ◽  
Aging Resistance ◽  
Long Life

Asphalt is the most commonly used material for pavement construction around the world, and therefore, it is vital to acquaint a practice that restores the reclaimed asphalt pavement (RAP) binder properties to the required level of performance by adding proper rejuvenators. However, a rejuvenator may perform better in the early stages of its application but may not necessarily perform better in the long run. The aim of this study is to assess the rejuvenation effect on the aging resistance of RAP binder in long-life performance through applying artificial aging. In this study, base virgin binder of pen grade 60/70 and RAP binder rejuvenated with Cereclor were subjected to artificial aging to simulate the short- and long-term aging effects. Penetration, softening point, ductility, and viscosity; saturates, aromatics, resins, and asphaltene (SARA) fractionation; and Fourier-transform infrared (FTIR) spectroscopy, bending beam rheometer (BBR), and dynamic shear rheometer (DSR) tests were conducted to evaluate the potential improvements in various properties of RAP binder. The results indicated that the physical, fractional composition, rheological, and aging resistance of RAP binder improved through the rejuvenation mechanism. Therefore, the rejuvenator improved the chemical structure through re-balancing the constituents in the colloidal system, even after long-term re-aging, which proves it to be an aging-resistant binder. Furthermore, it has been concluded that Cereclor has substantial rejuvenation potential even after applying artificial aging, and it can be utilized in pavement recycling to achieve long-life performance. Furthermore, the results depict good correlations between the physical, rheological, and chemical parameters of virgin and RAP binder.

scholarly journals The Influence of Reclaimed Asphalt Pavement on the Mechanical Performance of Bituminous Mixtures. An Analysis at the Mortar Scale

2020 ◽  
Vol 12 (20) ◽  
pp. 8343
Author(s):  
Ana E. Hidalgo ◽  
Fernando Moreno-Navarro ◽  
Raúl Tauste ◽  
M. Carmen Rubio-Gámez
Keyword(s):  
Mechanical Performance ◽  
Asphalt Pavement ◽  
Mechanical Analysis ◽  
Elastic Response ◽  
Reclaimed Asphalt Pavement ◽  
Reclaimed Asphalt ◽  
Bituminous Mixtures ◽  
Water Sensitivity ◽  
Term Performance

The main characteristics of bituminous mixtures manufactured with a considerable amount of reclaimed asphalt pavement (RAP), compared to conventional mixtures, are a reduction in workability, an increase in stiffness, and a loss of ductility, due to the presence of the aged bitumen contained in the RAP particles. To minimize these impacts, softer binders or rejuvenators are commonly used in the design of these mixtures in order to restore part of the ductility lost and to reduce the stiffness. In spite of previous investigations demonstrating that the mortar plays an essential role in the workability, long-term performance, and durability of bituminous mixtures (where cracking, cohesion, and adhesion problems all start at this scale), not many studies have assessed the impacts caused by the presence of RAP. In response to this, the present paper analyzes the workability, fatigue performance, and water sensitivity of bituminous mortars containing different amounts of RAP (from 0% to 100%) and rejuvenators. Mortar specimens were compacted using a gyratory compactor and studied via dynamic mechanical analysis under three point bending configuration. The results demonstrated that the presence of RAP reduces the workability and ductility of asphalt mortars. However, it also causes an increase in their stiffness, which induces a more elastic response and causes an increase in their resistance to fatigue, which could compensate for the loss of ductility. This aspect, together with the low water sensitivity shown, when using Portland cement as an active filler, would make it possible to produce asphalt materials with high RAP contents with a similar long-term mechanical performance as traditional ones. In addition, the use of rejuvenators was demonstrated to effectively correct the negative workability and ductility impacts caused by using RAP, without affecting the fatigue resistance and material adhesion/cohesion.

Use of Blended Binder Tests to Estimate Performance of Mixtures with High Reclaimed Asphalt Pavement/Recycled Asphalt Shingles Content

2021 ◽  
pp. 036119812199742
Author(s):  
Yuan Zhang ◽  
Daniel Swiertz ◽  
Hussain U. Bahia
Keyword(s):  
Asphalt Pavement ◽  
Effective Means ◽  
Creep Recovery ◽  
Reclaimed Asphalt Pavement ◽  
Recycled Asphalt ◽  
Performance Properties ◽  
Reclaimed Asphalt ◽  
Recycled Asphalt Shingles ◽  
Asphalt Shingles

The purpose of this study is to assess the use of blended binder tests to estimate mixture performance properties of high reclaimed asphalt pavement (RAP)/recycled asphalt shingles (RAS) mixtures utilizing recycling agents as a means to evaluate different recycling agents and estimate their doses for a given mixture. Blended binder properties are measured by using standard performance grading (PG) and PG+ test methods and correlating the results with corresponding performance properties of mixtures. Blended binders consisting of virgin and recovered binders and recycling agents were prepared and tested for PG grading properties, multiple stress creep recovery grades, and linear amplitude sweep fatigue life after the rolling thin-film oven and pressure aging vessel aging. Mixtures were tested for rutting resistance and cracking resistance at intermediate temperature and at low temperatures after being subjected to short-term oven aging and long-term oven aging. The correlation between the blended binder properties and mixture performance properties is used to identify the binder test parameters that can be used to predict the long-term performance of high RAP/RAS mixtures and the effects of various recycling agents. Results generally indicate that use of direct testing of recovered binders with recycling agents is an effective means to estimate required initial dose for recycling agent, and testing actual blended binders can be used to predict mixture performance-related properties for the testing conditions used in this study.

Long-Term Durability Studies on Chemically Treated Reclaimed Asphalt Pavement Material as a Base Layer for Pavements

2017 ◽  
Vol 2657 (1) ◽  
pp. 1-9 ◽  
Author(s):  
Anand J. Puppala ◽  
Aravind Pedarla ◽  
Bhaskar Chittoori ◽  
Vijay Krishna Ganne ◽  
Soheil Nazarian
Keyword(s):  
Fly Ash ◽  
Asphalt Pavement ◽  
Construction Material ◽  
El Paso ◽  
Base Material ◽  
The United States ◽  
Base Layer ◽  
Reclaimed Asphalt Pavement ◽  
Reclaimed Asphalt

For several years reclaimed asphalt pavement (RAP) material has been used as a construction material in hot-mix asphalt (HMA) to reduce material costs and stabilize pavements. Of the 45 million tons of RAP produced every year in the United States, only 33% is being used in HMA. Recent studies have demonstrated that RAP can be used effectively in base layers when it is blended with aggregate base materials and stabilized with cement or fly ash additives. This adoption in the pavement base layer helps maximize the reutilization of RAP material and minimize its disposal in landfills, thereby making it an environmentally friendly practice. However, studies reported so far addressed only the strength and stiffness characteristics of stabilized RAP in base layers in the short term, and not many studies have addressed its long-term behavior. In this study the long-term durability of untreated as well as stabilized specimens was tested by conducting standard durability testing to replicate the moisture fluctuations in the field from seasonal variations. In addition, leachate studies were conducted to examine the effect of rainfall infiltration on the leachability of the cement or fly ash stabilizer from stabilized RAP mixtures. Durability studies revealed a very low volumetric change and good retaining strength at the end of three, seven, and 14 cycles for RAP material from the El Paso, Texas, area, and leachate tests proved that the leaching of cement or fly ash stabilizer from RAP mixes cannot be considered to be a concern for long-term performance. However, approximately 2 years of field infiltration were replicated in the laboratory in this study. Of the several RAP mixtures studied, the mixture composed of 60% RAP and 40% base material with 2% cement was identified as an effective long-term-performing mixture.

scholarly journals Performance Assessment of Reclaimed Asphalt Pavement (RAP) in Road Surface Mixtures

Recycling ◽  
2021 ◽  
Vol 6 (2) ◽  
pp. 32
Author(s):  
Vítor Antunes ◽  
José Neves ◽  
Ana Cristina Freire
Keyword(s):  
Current Knowledge ◽  
Asphalt Pavement ◽  
Permanent Deformation ◽  
Reclaimed Asphalt Pavement ◽  
Reclaimed Asphalt ◽  
Bituminous Mixtures ◽  
Road Pavement ◽  
Water Sensitivity ◽  
Short And Long Term

Considerable amounts of Reclaimed Asphalt Pavement (RAP) are produced every year, as the road network requires maintenance to ensure the safety and comfort of its users. RAP is a 100% recyclable material and a useful fit to be re-introduced into another cycle without downgrading its functionality. Despite the current knowledge about the benefits associated with RAP use, it is not yet largely applied in several countries. This paper aims to validate, on the basis of both short- and long-term mechanical behaviours, the application of a bituminous mixture with a high RAP incorporation rate (75%) in road pavement wearing courses. A crude tall oil rejuvenator was used. Both short- and long-term oven ageing procedures were employed to simulate the ageing that occurs during mixture production and in-service life, respectively. The tests for validating the RAP mixture as an alternative solution comprised stiffness, resistance to fatigue, permanent deformation, and determination of the water sensitivity. Furthermore, the RAP bitumen mobilisation degree was evaluated and a mixing protocol was established. In comparison with virgin bituminous mixtures, it was found that, in general, the high RAP mixtures presented similar or better behaviour. The ageing process had a hardening effect namely in terms of stiffness and resistance to permanent deformation, without significant effects on the resistance to fatigue and water damage.

scholarly journals Effect of Rejuvenated Binder on the Pavement Rutting Performance at Different Aging Levels

2020 ◽  
Vol 2020 ◽  
pp. 1-8
Author(s):  
Hesham A. Ali ◽  
Farshad Haddadi ◽  
Mojtaba Mohammadafzali ◽  
Greg Sholar ◽  
Howard Moseley
Keyword(s):  
Asphalt Pavement ◽  
Effective Means ◽  
Reclaimed Asphalt Pavement ◽  
Test Results ◽  
Short Term ◽  
Moisture Susceptibility ◽  
Reclaimed Asphalt ◽  
Performance Grading ◽  
Determining Factor

The use of Reclaimed Asphalt Pavement (RAP) in virgin mixtures is an effective means of promoting sustainability. The objective of this research was to investigate the effect of rejuvenated binder on the rutting performance and moisture susceptibility of high RAP content mixtures. All mixtures were tested at three aging levels, one short-term aging level, and two long-term aging levels. The performance of the specimens and the level of diffusion were measured and compared, and the correlation between binder test and rutting test results was evaluated. Based on the results, the degree of diffusion is not a determining factor in the performance of the mixture. However, the amount of the rejuvenator and Superpave performance grading (PG) of the rejuvenated binder is the most effective parameter. Results indicate that the short-term aged recycled mix exhibits a better rutting resistance than the virgin mix when its HTPG is 6°C higher than the virgin mix.

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