scholarly journals THE STUDY OF RECYCLED ASPHALT CONCRETE AGGREGATE AS SUBBASE COURSE MATERIAL IN COLD REGIONS

1999 ◽  
Vol 4 ◽  
pp. 127-134
Author(s):  
Ryuji ABE ◽  
Morito TAKAHASHI ◽  
Yasunori HAYASAKA
Author(s):  
Vasyl Nagaychuk ◽  
Sergii Illiash

The hot in-place recycling (HIR) belongs to the successful strategies of asphalt concrete pavements rehabilitation that provides effective elimination of such surface defects as cracking, rutting, stripping, raveling, and bleeding including defects caused by the non-conformity of asphalt concrete to the standard specifications. The HIR technologies are divided into four methods: «Reshape», «Repave», «Remix», and «Remix Plus». Among those methods, «Remix» and «Remix Plus» are more complicated technologically and are connected with changing the composition of existed (old) asphalt concrete. The composition of existed asphalt concrete should be corrected through the addition some of new components (aggregates, asphalt binder, rejuvenating agent, or new hot-mixed asphalt concrete mixture) to the hot-milled old asphalt layer. This article is dedicated to the methods of calculation of new and recycled aggregate mixture gradation regarding to the Ukrainian standards. The proposed methods of calculation consider such main peculiarities of HIR-recycled materials and layer design as: 1) old asphalt concrete, particularly its aggregate parts, can used in a non-fractioned form only; 2) HIR-recycled asphalt concrete layer should be designed with or without the maximal layer thickness restriction. The proposed methods also give the possibility to correct the technological process if the calculated amount of new material necessitated to the correction of old asphalt concrete aggregate grading does not allow to maintain the projected layer thickness. The implementation of the proposed technique of calculation of aggregate grading with and without restriction of the maximal thickness of recycled asphalt concrete layer allows enhance quality of recycled materials and promotes the entire adaptation of HIR technologies to the Ukrainian standards. Keywords: hot in-place recycling of asphalt concrete, «Remix», «Remix Plus», recycled asphalt concrete mixture, correction of aggregate gradation.


2021 ◽  
Vol 26 ◽  
pp. 100429
Author(s):  
Petr Kucera ◽  
Martin Lidmila ◽  
Petr Jasansky ◽  
Marek Pycha ◽  
Michael P.N. Burrow ◽  
...  

Materials ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 717
Author(s):  
Andrzej Głuchowski ◽  
Raimondas Šadzevičius ◽  
Rytis Skominas ◽  
Wojciech Sas

Buried pipe design requires knowledge about the fill to design the backfill structure. The interaction between the backfill envelope and the pipe impacts the structural performance of the buried pipe. The backfill material and compaction level respond to the backfill’s overall strength and, therefore, for pipe-soil interaction. The strength of backfill material is described in terms of modulus of soil reaction E’ and constrained modulus Eode. As the E’ is an empirical parameter, the Eode can be measured in the laboratory by performing the oedometer tests. In this study, we have performed extensive oedometric tests on five types of anthropogenic materials (AM). Three of them are construction and demolition materials (C–D materials) namely, recycled concrete aggregate (RCA), crushed brick (CB), and recycled asphalt pavement (RAP). Two of them are industrial solid wastes (ISW) namely, fly ash and bottom slag mix (FA + BS) and blast furnace slag (BFS). The results of the tests revealed that AM behaves differently from natural aggregates (NA). In general, the Eode value for AM is lower than for NA with the same gradation. Despite that, some of AM may be used as NA substitute directly (RCA or BFS), some with special treatment like CB and some with extra compaction efforts like RAP or FA + BS.


2013 ◽  
Vol 40 (2) ◽  
pp. 181-187 ◽  
Author(s):  
Jean-Pascal Bilodeau ◽  
Guy Doré ◽  
Jonas Depatie

The use of recycled asphalt pavement (RAP) aggregates as replacement for new materials in the pavement base weakens the layer in regards to the resistance to permanent deformation under repeated loading. A mechanistic based design procedure is proposed to ensure that base layers containing RAP particles have a similar rutting behaviour to base layers made of virgin aggregates. The design procedure allows calculating an asphalt concrete thickness increase that is based on permanent deformation behaviour of base materials. The calculation approach is based on multistage triaxial permanent deformation tests performed on granular material samples with varied RAP content. The tests allowed proposing an equation that relates permanent strain rate, RAP content, and deviatoric stress, which is the basis of the design procedure. Design charts are proposed to select adequate thickness increase for the asphalt concrete layer according to the expected RAP content in the base layer and asphalt concrete modulus.


Author(s):  
Jhony Habbouche ◽  
Ilker Boz ◽  
Benjamin Shane Underwood ◽  
Cassie Castorena ◽  
Saqib Gulzar ◽  
...  

The objective of this paper is to provide information from multiple perspectives on the current state of the practice with regard to using recycled materials and recycling agents (RAs) in asphalt concrete mixtures. This information was collected through a survey of U.S. transportation agencies and RA suppliers combined with a search of RA-related specifications and pilot projects previously constructed. Moreover, a case study describing the Virginia Department of Transportation’s experience with RAs provides a tangible example of how at least one agency is approaching the potential implementation of these technologies. This practice review was achieved by documenting the experience, lessons learned, and best practices of multiple asphalt experienced contractors and asphalt binder suppliers in the Virginia area. This paper follows a similar survey conducted in 2014 as part of NCHRP 09-58 and provides a second look at the use of RAs across North America. Not all state departments of transportation have experience with using RAs. Factors preventing the use of RAs included specification limitations, lack of expertise in processing recycled materials, supporting data, and negative prior experiences. Developing a performance-based testing framework is mandatory for the successful use of RAs. In general, good and frequent communication with the RA supplier is critical and necessary during the planning stages, the production of mixtures, and the continuous quality control by the supplier to resolve issues when they arise. Finally, a strong quality control and quality assurance-testing program should be implemented to ensure that materials meet the properties needed to produce a good-performing mixture.


2020 ◽  
Vol 5 (4) ◽  
pp. 34
Author(s):  
Patricia Kara De Maeijer

This Special Issue “Recent Advances and Future Trends in Pavement Engineering” has been proposed and organized to present recent developments in the field of innovative pavement materials and engineering. For this reason, the articles and state-of-the-art reviews highlighted in this editorial relate to different aspects of pavement engineering, from recycled asphalt pavements to alkali-activated materials, from hot mix asphalt concrete to porous asphalt concrete, from interface bonding to modal analysis, from destructive testing to non-destructive pavement monitoring by using fiber optics sensors.


2019 ◽  
Vol 12 (1) ◽  
pp. 250 ◽  
Author(s):  
Debora Acosta Álvarez ◽  
Anadelys Alonso Aenlle ◽  
Antonio José Tenza-Abril ◽  
Salvador Ivorra

The main objective of this work is to evaluate the properties of hot asphalt mixtures that have been manufactured with different recycled concrete aggregate (RCA) percentages (0%, 20%, 40%, 60% and 80% of the fraction 5–13 mm) and asphalt (4%, 4.5% and 5%). Dense asphalt mixtures were made; partially replacing the natural aggregate (NA) fraction between 5 and 13 mm. Marshall specimens were manufactured to determine the main properties of the asphalt concrete (AC) in terms of density, voids, stability and deformation. Additionally, the optimal asphalt content (OAC) was determined, and measured the water sensibility, the stiffness modulus and the permanent deformation. The results corroborate the potential for using these sources of construction and demolition waste (CDW) as a RCA in asphalt concrete and show that the hot asphalt mixtures with up to 40% substitution of natural aggregate by recycled aggregate in the fraction 5–13 mm present good behavior.


2013 ◽  
Vol 668 ◽  
pp. 309-312
Author(s):  
Jia Liang

In the past few years, recycled asphalt materials have been used successfully in asphalt concrete pavement in China. However, there are no results of the performance of using abson method and vacuum rotating reclaim to recycled asphalt. The objective of this study is to investigation performance of recycled asphalt materials using abson method and vacuum rotating reclaim. Abson method and vacuum rotating reclaim were implemented to analyze the characteristics of different aging degree recycled asphalt in this article. Lanlian-70 asphalt put into pressure aging vessels after the time of 0 hour,5 hour,10 hour,15 hour, 20 hour of aging. Afterwards, the different aging degree asphalt was dissolved by trichloroethylene, and then asphalt solution reclaimed using abson method and vacuum rotating reclaim. In the end, the performances of recycled asphalt were tested, such as penetration, softening point, ductility. The characteristics were compared of different aging degree recycled asphalt and origin asphalt. Comparison results indicate that the indexes of recycled asphalt are decease of the penetration and ductility, increase of softening point. However, decreased value and increased value is minimal. Therefore, recycled asphalt will not make asphalt ageing in the process of recycled asphalt.


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