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

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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Rejuvenator Influence on Aged Binder Material Properties

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.730.380 ◽

2017 ◽

Vol 730 ◽

pp. 380-388 ◽

Cited By ~ 2

Author(s):

Michal Varaus ◽

Tomas Koudelka ◽

Pavel Sperka

Keyword(s):

Asphalt Pavement ◽

Asphalt Binder ◽

Asphalt Mixtures ◽

Reclaimed Asphalt Pavement ◽

Optimum Amount ◽

Bending Beam Rheometer ◽

Reclaimed Asphalt ◽

Binder Material ◽

Aged Binder ◽

Ball Test

As the amount of reclaimed asphalt pavement (RAP) material used in asphalt mixtures has increased recently, it is vital to address problems regarding aged binder incorporated in RAP. Asphalt binder hardens during its production process as well as during service life of pavements. External influences such as oxygen and ultraviolet radiation affect greatly bitumen characteristics. Thanks to adding rejuvenating agents, the original binder properties should be recovered and resulting asphalt binder parameters should become equal to those measured upon the reference material. In this study, four different rejuvenator agents and one neat soft binder were employed to rejuvenate the artificially aged binder by a complete blending between both constituents. Thereafter, empirical as well as performance based binder properties were examined with a dynamic shear rheometer (DSR) and with a bending beam rheometer (BBR). Three different dosages of each rejuvenator were added to evaluate the required amount for the original binder properties to be restored. Moreover, the softening efficiency of each agent was assessed by means of the Ring and Ball test. Finally, the optimum amount of each rejuvenator needed for the blend to achieve the target specification was determined. It can be concluded that the rejuvenators affect binder properties greatly, and mainly in a positive way. However, the data also indicate significant discrepancies between the types of the rejuvenator.

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Desempenho de misturas asfálticas recicladas mornas e sua influência no dimensionamento do revestimento asfáltico

Semina Ciências Exatas e Tecnológicas ◽

10.5433/1679-0375.2020v41n2p157 ◽

2020 ◽

Vol 41 (2) ◽

pp. 157

Author(s):

Fernanda Gadler ◽

Leonardo Fagundes Rosemback Miranda ◽

Joe Villena

Keyword(s):

Resilient Modulus ◽

Asphalt Pavement ◽

Asphalt Binder ◽

Binder Content ◽

Asphalt Mixtures ◽

Recycled Concrete ◽

Concrete Aggregate ◽

Reclaimed Asphalt Pavement ◽

Recycled Concrete Aggregate ◽

Reclaimed Asphalt

The main purpose is to evaluate the performance of asphalt regarding resilient modulus and fatigue curve.The asphalt was produced with two wastes, reclaimed asphalt pavement (RAP) and recycled concrete aggregate (RCA), using the technique of warm mixtures. The evaluation includes, based on these parameters, the thickness differences in the design of asphalt layer for each mixture. Five asphalt mixtures were produced with incorporation of RAP and RCA, in different gradation fractions (fine and/or course), without adding any natural aggregate. In view of the aim of the article, the mixtures were evaluated through tests of resilient modulus and fatigue life, in order to support the design, establishing the necessary thickness to meet traffic demands of each mixture. The design was performed using MeDiNa software. Among all results, it is highlighted that asphalt binder content is the component that exerts the greatest influence on the resilient modulus of the mixtures. As for fatigue, in addition to the binder content, the possible anchoring of the asphalt binder in the pores of the RCA may have favored the performance of the GARC_MRAP mixture. Still, all mixtures with RAP, both in fine or course fraction, resulted in lower coating thicknesses compared to the REF, for the same load request, with better performance of the GARC_MRAP mixture produced with 100 % waste material and incorporation of only 3.1 % neat binder.

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Use of Rejuvenators to Rejuvenate Asphalt Binders in RAP

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.737.547 ◽

2017 ◽

Vol 737 ◽

pp. 547-553

Author(s):

Iva Krcmova ◽

Petr Hyzl ◽

Pavla Nekulova ◽

Pavel Coufalik ◽

Ondrej Dasek

Keyword(s):

Asphalt Pavement ◽

Asphalt Binder ◽

Chemical Properties ◽

Asphalt Binders ◽

Reclaimed Asphalt Pavement ◽

Reclaimed Asphalt ◽

Aged Asphalt ◽

Empirical Tests ◽

The Individual ◽

Physical And Chemical

With increased demand and limited aggregate and binder supply, hot mix asphalt (HMA) producers discovered that reclaimed asphalt pavement (RAP) is a valuable component in HMA. This paper is concerned with the current issue of higher using RAP (Reclaimed Asphalt Pavement) in asphalt mixtures for pavement wearing courses. It describes the effects of application of three types of rejuvenation additives on properties of aged asphalt binders made from a regular RAP. These rejuvenation additives restore the physical and chemical properties of aged binders. In addition, the aged asphalt binder with rejuvenators applied was subjected to a short-term laboratory aging using the RTFOT (Rolling Thin Film Oven Test). This method simulate aging asphalt binder during the manufacturing process and laying. To assess the binder properties, both the standard empirical tests and more advanced functional tests (dynamic shear rheometer and bending beam rheometer) have been performed. Last part of the paper provides an evaluation of the individual rejuvenation additives. Based on the results it can be concluded that a positive change in properties of aged asphalt binder after applying all the three rejuvenators has been proven.

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Variability of Reclaimed Asphalt Pavement (RAP) Properties within a State and Its Effects on RAP Specifications

Transportation Research Record Journal of the Transportation Research Board ◽

10.1177/0361198120917679 ◽

2020 ◽

Vol 2674 (6) ◽

pp. 73-84

Author(s):

Alexander J. Austerman ◽

Walaa S. Mogawer ◽

Kevin D. Stuart

Keyword(s):

Asphalt Pavement ◽

Asphalt Binder ◽

Mixture Design ◽

Reclaimed Asphalt Pavement ◽

Reclaimed Asphalt ◽

Performance Specifications ◽

Aged Binder ◽

Transportation Agencies ◽

The U.S

Reclaimed Asphalt Pavement (RAP) is a highly recyclable material that provides a source of aggregates and asphalt binder to be re-utilized in new paving mixtures. State transportation agencies in the U.S. have constructed their specifications to allow for the use of RAP in new paving mixtures, but with conditions so that suitably performing mixtures are developed. These conditions are imposed because of concerns that the aged binder contained within the RAP may negatively impact the resultant mixtures performances. Many state transportation agencies have constructed their specifications with respect to the AASHTO guidance on utilizing RAP in Superpave mixtures. Questions remain as to the accuracy of these methods, especially if the RAP stockpiles’ properties vary greatly. The purpose of this study was to characterize and compare the properties of the RAP stockpiles being used throughout Massachusetts and to determine the impacts that these properties have on the currently utilized specifications for RAP. The properties of the RAP stockpiles within Massachusetts varied greatly. No geographical or regionalization of RAP properties could be made. By default, the current specifications for using RAP makes no distinction between RAP stockpile properties, especially at smaller percentages like <15% or at low RAP binder ratios (RAPBR). The data from this study demonstrated that this could lead to mixtures without the appropriate virgin binder grade and therefore they could exhibit subpar performance. Specifications should be revised to require more thorough testing of RAP for each mixture design, regardless of the allowable percentage or RAPBR, to ensure adequate mixture performance is maintained.

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Effect of Aged Binder Distribution on the Fracture Tolerance of Asphalt Mixtures with Reclaimed Asphalt Pavement

Journal of Testing and Evaluation ◽

10.1520/jte20210227 ◽

2021 ◽

Vol 50 (2) ◽

pp. 20210227

Author(s):

Yu Yan ◽

David Hernando ◽

Bongsuk Park ◽

Gabriele Tebaldi ◽

Reynaldo Roque

Keyword(s):

Asphalt Pavement ◽

Asphalt Mixtures ◽

Reclaimed Asphalt Pavement ◽

Reclaimed Asphalt ◽

Fracture Tolerance ◽

Aged Binder

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Mechanical Performance of Reclaimed Asphalt Pavement Modified with Waste Frying Oil and Crumb Rubber

Materials ◽

10.3390/ma14112781 ◽

2021 ◽

Vol 14 (11) ◽

pp. 2781

Author(s):

Munder Bilema ◽

Mohamad Yusri Aman ◽

Norhidayah Abdul Hassan ◽

Zubair Ahmed Memon ◽

Hend Ali Omar ◽

...

Keyword(s):

Asphalt Pavement ◽

Asphalt Binder ◽

Asphalt Mixture ◽

Moisture Damage ◽

Crumb Rubber ◽

Asphalt Mixtures ◽

Reclaimed Asphalt Pavement ◽

Waste Frying Oil ◽

Rutting Resistance ◽

Reclaimed Asphalt

Researchers are exploring the utilisation of reclaimed asphalt pavement (RAP) as a recycled material to determine the performance of non-renewable natural aggregates and other road products such as asphalt binder, in the construction and rehabilitation stage of asphalt pavements. The addition of RAP in asphalt mixtures is a complex process and there is a need to understand the design of the asphalt mixture. Some of the problems associated with adding RAP to asphalt mixtures are moisture damage and cracking damage caused by poor adhesion between the aggregates and asphalt binder. There is a need to add rejuvenators to the recycled mixture containing RAP to enhance its performance, excepting the rutting resistance. This study sought to improve asphalt mixture performance and mechanism by adding waste frying oil (WFO) and crumb rubber (CR) to 25 and 40% of the RAP content. Moreover, the utilisation of CR and WFO improved pavement sustainability and rutting performance. In addition, this study prepared five asphalt mixture samples and compared their stiffness, moisture damage and rutting resistance with the virgin asphalt. The results showed enhanced stiffness and rutting resistance of the RAP but lower moisture resistance. The addition of WFO and CR restored the RAP properties and produced rutting resistance, moisture damage and stiffness, which were comparable to the virgin asphalt mixture. All waste and virgin materials produce homogeneous asphalt mixtures, which influence the asphalt mixture performance. The addition of a high amount of WFO and a small amount of CR enhanced pavement sustainability and rutting performance.

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Laboratory Observation and Evaluation of Asphalt Blends of Reclaimed Asphalt Pavement Binder with Virgin Binder using SEM/EDS

Transportation Research Record Journal of the Transportation Research Board ◽

10.1177/0361198118782023 ◽

2018 ◽

Vol 2672 (28) ◽

pp. 69-78 ◽

Cited By ~ 5

Author(s):

Yanxu Jiang ◽

Xingyu Gu ◽

Zhou Zhou ◽

Fujian Ni ◽

Qiao Dong

Keyword(s):

Asphalt Pavement ◽

Energy Dispersive Spectrometer ◽

Asphalt Mixture ◽

Asphalt Mixtures ◽

Reclaimed Asphalt Pavement ◽

Recycled Asphalt ◽

Laboratory Observation ◽

Reclaimed Asphalt ◽

Recycling Agent ◽

Aged Binder

In this paper, microscopic technique tests were carried out to observe and evaluate the degree of blending between reclaimed asphalt pavement (RAP) binder and virgin binder in hot mixed asphalt mixture. To this end, titanium dioxide (TiO2) was selected as a tracer to tag virgin binder. Scanning electron microscope/energy dispersive spectrometer (SEM/EDS) experiments were conducted on compacted recycled asphalt mixtures and virgin asphalt mixtures. The element mass ratio of titanium over sulfur (Ti:S) was proposed as an quantitative indicator of blending ratio to accurately evaluate the degree of partial blending between RAP and virgin binders. The SEM/EDS images visually displayed the partial blending in high RAP mixtures. Different partial blending patterns were observed under different handling processes. The results of EDS tests indicated that with the increase of the RAP content, the blending degree of virgin and aged binder decreased rapidly, and the homogeneity of blended binder became weakened. In addition, aging process and recycling agent could improve the efficiency of RAP binder as it is blended with virgin one, and it should be noted that the inter-diffusion of old and new binders need enough time. This methodology provides a systemic approach to determine the degree of binder blending in RAP mixture.

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