PARTICULARITIES OF HOT-IN-PLACE RECYCLING WITH CHANGING THE ASPHALT CONCRETE MIXTURE AGGREGATE GRADATION

2018 ◽  
pp. 20-27
Author(s):  
Vasyl Nagaychuk ◽  
Sergii Illiash
Keyword(s):  
Layer Thickness ◽  
Asphalt Concrete ◽  
Recycled Aggregate ◽  
Concrete Mixture ◽  
Concrete Aggregate ◽  
Recycled Asphalt ◽  
Recycled Materials ◽  
Aggregate Gradation ◽  
Methods Of Calculation ◽  
Concrete Layer

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.

Review From Multiple Perspectives for the State of the Practice on the Use of Recycled Asphalt Materials and Recycling Agents in Asphalt Concrete Surface Mixtures

2021 ◽  
pp. 036119812110611
Author(s):  
Jhony Habbouche ◽  
Ilker Boz ◽  
Benjamin Shane Underwood ◽  
Cassie Castorena ◽  
Saqib Gulzar ◽  
...  
Keyword(s):  
Quality Control ◽  
Asphalt Concrete ◽  
Asphalt Binder ◽  
Concrete Surface ◽  
Lessons Learned ◽  
Multiple Perspectives ◽  
Recycled Asphalt ◽  
Recycled Materials ◽  
Continuous Quality ◽  
Virginia Department

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.

scholarly journals Influence of Partial Coarse Fraction Substitution of Natural Aggregate by Recycled Concrete Aggregate in Hot Asphalt Mixtures

2019 ◽  
Vol 12 (1) ◽  
pp. 250 ◽  
Author(s):  
Debora Acosta Álvarez ◽  
Anadelys Alonso Aenlle ◽  
Antonio José Tenza-Abril ◽  
Salvador Ivorra
Keyword(s):  
Asphalt Concrete ◽  
Coarse Fraction ◽  
Asphalt Mixtures ◽  
Recycled Concrete ◽  
Construction And Demolition Waste ◽  
Recycled Aggregate ◽  
Concrete Aggregate ◽  
Recycled Concrete Aggregate ◽  
Demolition Waste ◽  
Natural Aggregate

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.

Total Recycled Asphalt Mixes: Characteristics and Field Performance

2019 ◽  
Vol 2673 (12) ◽  
pp. 149-162 ◽  
Author(s):  
Fazal R. Safi ◽  
Imad L. Al-Qadi ◽  
Kamal Hossain ◽  
Hasan Ozer
Keyword(s):  
Complex Modulus ◽  
Steel Slag ◽  
Field Performance ◽  
Recycled Concrete ◽  
Environmental Benefits ◽  
Recycled Aggregates ◽  
Concrete Aggregate ◽  
Recycled Asphalt ◽  
Recycled Materials ◽  
Transverse Cracking

The use of recycled materials in asphalt concrete (AC) pavement has increased significantly because of their economic and environmental benefits. The use of recycled materials can pose risks to the performance of asphalt pavements, however. The Illinois Department of Transportation developed five total recycled asphalt (TRA) mixes in the pursuit of environmentally sustainable pavements. These mixes contain up to 60% asphalt binder replacement (ABR) obtained from reclaimed asphalt pavement (RAP) and recycled asphalt shingles. Virgin aggregates were replaced by 100% recycled aggregates including RAP, steel slag, and recycled concrete aggregate (RCA). Based on laboratory testing, all the mixes offered excellent rutting resistance because of their high ABR content. The TRA mixes were relatively less compliant and not very sensitive to field aging, whereas indirect tensile strength tests showed indistinguishable results. All mixes had comparable complex modulus |E*| and phase angle ([Formula: see text]) values at low temperatures. Laboratory-compacted specimens had relatively low flexibility index (FI) compared with field cores taken after construction. The FI values of the field cores decreased with aging, higher recycled materials content, or both. An exponential increase in transverse cracking was observed in the field cores because of their relatively high ABR, RCA/steel slag content, or both. The progression of field transverse cracking over time and FI values are well correlated. A three-dimensionally balanced mix design was introduced and used successfully to distinguish between AC mixes; it is proposed as a tool for better control mix designs and optimum field performance.

Utilization of Construction and Demolition Debris Under Traffic-Type Loading in Base and Subbase Applications

2000 ◽  
Vol 1714 (1) ◽  
pp. 33-39 ◽  
Author(s):  
Thomas Bennert ◽  
Walter J. Papp ◽  
Ali Maher ◽  
Nenad Gucunski
Keyword(s):  
New Jersey ◽  
Resilient Modulus ◽  
Permanent Deformation ◽  
Recycled Concrete ◽  
Concrete Aggregate ◽  
Recycled Asphalt ◽  
Recycled Materials ◽  
Laboratory Test Results ◽  
Mixed Samples ◽  
Construction And Demolition Debris

As construction and remediation take place throughout New Jersey, the amount of construction and demolition debris increases, while the availability of landfill space decreases. A viable solution for disposing of these materials is to incorporate them into base and subbase applications. An extensive laboratory program was conducted on two types of construction and demolition debris: recycled concrete aggregate (RCA) and recycled asphalt pavement aggregate (RAP). These two materials were compared with dense-graded aggregate base coarse (DGABC), which currently is being used in roadway base applications in New Jersey. Both RCA and RAP were mixed at various percentages with the DGABC to evaluate whether an optimum mix blend could be formulated. The materials were evaluated under a traffic-type loading scheme that included resilient modulus and permanent deformation via cyclic triaxial testing. Laboratory tests indicated that the RAP, RCA, and DGABC blended materials all obtained higher resilient modulus values than the currently used DGABC. The permanent deformation results indicated that the RCA mixed samples obtained the lowest amount of permanent deformation when the material was cyclically loaded to 100,000 cycles. In contrast, the permanent deformation testing on RAP mixed samples resulted in the highest amount of permanent deformation at the same number of cycles. Existing models currently used for quarried base and subbase materials were used to predict the permanent deformation in the recycled materials. Laboratory test results indicated that these models could be used for predicting permanent deformation in unbound recycled materials.

scholarly journals Development and Guidance of Green Concrete for Leed™ Applications

2010 ◽  
Vol 5 (4) ◽  
pp. 111-120
Author(s):  
John T Kevern
Keyword(s):  
Green Building ◽  
Cementitious Materials ◽  
Recycled Concrete ◽  
Supplementary Cementitious Materials ◽  
Recycled Aggregate ◽  
Strength Development ◽  
Concrete Aggregate ◽  
Total Contribution ◽  
Recycled Materials ◽  
Concrete Mixtures

As green building rating systems such as LEED™ become more popular, the use of recycled materials in construction is increasing. Concrete can be produced with significant quantities of supplementary cementitious materials or recycled aggregate materials. However, modifying concrete mixture proportions for improved recycled content credits also impacts strength and long-term durability. Without properly understanding the effects recycled materials have on concrete, greener concrete can be less desirable from a lifecycle perspective from poor durability. This research investigates the impacts different types and quantities of supplementary cementitious materials and recycled concrete aggregate have on strength development and concrete durability, specifically deicer scaling. Improvements to deicer scaling resistance were investigated using a novel soybean oil sealer. The concrete mixtures were also evaluated within the LEED™ recycled materials criteria for selection based on economy and total contribution value. Considerations are included to assist designers in the selection of greener concrete mixtures for appropriate applications.

A Study of Relationship Between Residual Asphalt in Aggregate Surface and Aging Degree of its Asphalt

2012 ◽  
Vol 602-604 ◽  
pp. 985-989
Author(s):  
Wen Tsung Liu ◽  
Ming Ho Tu
Keyword(s):  
Asphalt Concrete ◽  
Coarse Aggregate ◽  
Soxhlet Extraction ◽  
Recycled Asphalt ◽  
Recycled Materials ◽  
The Road ◽  
Coarse Aggregates ◽  
Processing Techniques ◽  
Relationship Of ◽  
The Relationship

Abstract. Laying the road, a lot of asphalt mixing plants use recycled asphalt concrete instead of fresh asphalt concrete. The main reason is that the plants don’t need to provide the viscosity inspection when testing because it is not mentioned in the contract. Even if the value of bitumen viscosity is high in the test report, it is difficult to prove effectively whether to join the asphalt recycled materials or not. This study is to explore the relationship between their extraction of bitumen and coarse aggregate cleanliness by Soxhlet extraction from asphalt recycled materials and fresh asphalt concrete. Besides, we look for the differences after washing asphalt. The research focuses on the method to view the number of the cleanliness on the coarse aggregate surface. The coarse aggregates will be divided into four kinds of sieve (3/4 ", 1/2", 3/8 ", # 4) in process. The selected range is by the built-in program of Photoshop_CS3. We determined the percentage of asphalt area on the aggregates in line with the RGB values. We further used the image processing techniques (Matlab program of image analysis) to assess the relationship of the above mention and compared the basic properties of the asphalt.

scholarly journals Providing interlayer adhesion of dissimilar layers of top road surfaces

2021 ◽  
Vol 274 ◽  
pp. 02003
Author(s):  
Talgat Gabdullin ◽  
Marat Makhmutov
Keyword(s):  
Layer Thickness ◽  
Asphalt Concrete ◽  
Road Construction ◽  
Concrete Mixture ◽  
Cement Concrete ◽  
The Road ◽  
Road Pavement ◽  
Concrete Base ◽  
Pavement Layers ◽  
Asphalt Concrete Pavement

The article reviews the option of how to make the top pavement of asphalt-concrete mixture adhere reliably to the base, which is the underlying cement-concrete coating. The bitumen-latex emulsion is suggested as a binder for the two pavement layers. The research aimed to determine the optimal layer thickness of the bituminous-latex emulsion to be applied and achieve the maximum interlayer adhesion between the top asphalt-concrete pavement and the cement-concrete base. After full-scale experiments, the required layer thickness of the bitumen-latex emulsion was 2 mm. With this layer thickness of the binder, road pavement layers do not delaminate and shear when stressed by the intensive flows of vehicles moving on the roads. The results obtained are important for the road construction industry for suggesting the formulation of bitumen-latex emulsion and finding the most effective layer thickness to be applied. The suggested formulation of a bitumen-latex emulsion is frost-resistant. The article describes the experimental steps for determining the optimal application thickness at a fair length. The maintenance-free life of roads with an asphalt-concrete mixture on a cement-concrete base interlayered with a bitumen-latex emulsion as a binder is assumed to get much longer.

The feasibility of using asphalt concrete with a high percentage of recycled asphalt material in a railway trackbed layer

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