Upgraded Overlay Tester and Its Application to Characterize Reflection Cracking Resistance of Asphalt Mixtures

Upgraded Overlay Tester and Its Application to Characterize Reflection Cracking Resistance of Asphalt Mixtures PDF Author: Fujie Zhou
Publisher:
ISBN:
Category : Pavements
Languages : en
Pages : 48

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Book Description
Reflection cracking is a major concern when placing an overlay on a cracked pavement. The opening and closing of joints and/or cracks induced by daily temperature cycles is a major contributor to reflection cracking. This mechanism is currently being simulated in the laboratory at the Texas Transportation Institute (TTI) using a specially modified overlay-tester device. To evaluate the overlay tester concept laboratory results are presented on cores from four Texas projects, three of which performed very poorly and one which performed excellently. The asphalt mixture on US 175 in Dallas was placed on a cracked stabilized base and did not have a single reflection crack after 10 years in service, whereas the mixtures on two projects were badly cracked after only few months. The results clearly show that the upgraded TTI overlay tester can effectively differentiate between the reflection cracking resistance of different asphalt mixtures. It is also found that the reflection cracking resistance of asphalt mixture has a good correlation with the asphalt binder properties. In this report the upgraded TTI overlay tester is also used to quantify the benefits of modified asphalt binders. This benefit is demonstrated with a single mix where specimens were prepared with a variety of asphalt binders. The mix prepared with PG 64-22 plus 3 percent SBR latex demonstrated superior reflection cracking resistance while still maintaining adequate rutting resistance. It is proposed that the overlay tester is a practical device which can be incorporated into mixture design systems, to complement the current systems, which often focus solely on minimizing rutting potential. In many instances it is necessary to optimize both crack resistance and rutting potential to obtain adequate long-term pavement performance.

Upgraded Overlay Tester and Its Application to Characterize Reflection Cracking Resistance of Asphalt Mixtures

Upgraded Overlay Tester and Its Application to Characterize Reflection Cracking Resistance of Asphalt Mixtures PDF Author: Fujie Zhou
Publisher:
ISBN:
Category : Pavements
Languages : en
Pages : 48

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Book Description
Reflection cracking is a major concern when placing an overlay on a cracked pavement. The opening and closing of joints and/or cracks induced by daily temperature cycles is a major contributor to reflection cracking. This mechanism is currently being simulated in the laboratory at the Texas Transportation Institute (TTI) using a specially modified overlay-tester device. To evaluate the overlay tester concept laboratory results are presented on cores from four Texas projects, three of which performed very poorly and one which performed excellently. The asphalt mixture on US 175 in Dallas was placed on a cracked stabilized base and did not have a single reflection crack after 10 years in service, whereas the mixtures on two projects were badly cracked after only few months. The results clearly show that the upgraded TTI overlay tester can effectively differentiate between the reflection cracking resistance of different asphalt mixtures. It is also found that the reflection cracking resistance of asphalt mixture has a good correlation with the asphalt binder properties. In this report the upgraded TTI overlay tester is also used to quantify the benefits of modified asphalt binders. This benefit is demonstrated with a single mix where specimens were prepared with a variety of asphalt binders. The mix prepared with PG 64-22 plus 3 percent SBR latex demonstrated superior reflection cracking resistance while still maintaining adequate rutting resistance. It is proposed that the overlay tester is a practical device which can be incorporated into mixture design systems, to complement the current systems, which often focus solely on minimizing rutting potential. In many instances it is necessary to optimize both crack resistance and rutting potential to obtain adequate long-term pavement performance.

Pilot Implementation of the Overlay Tester and Double-blade Saw

Pilot Implementation of the Overlay Tester and Double-blade Saw PDF Author: Xiaodi Hu
Publisher:
ISBN:
Category : Pavements
Languages : en
Pages : 38

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Book Description


Asphalt Paving Technology 2015

Asphalt Paving Technology 2015 PDF Author: Eugene Skok
Publisher: DEStech Publications, Inc
ISBN: 160595294X
Category : Technology & Engineering
Languages : en
Pages : 768

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Book Description
Recent research on asphalt binder aging and rejuvenatorsKey data on asphalt performance and formulationsUpdates on tests and specificationsFully-searchable text on CD-ROM (included) This series volume comprises research papers and technical reports developed within the U.S.-based Association of Asphalt Paving Technologists. The book is divided into sessions focused on technology, specifications, cold recycling of RAP, and rejuvenators, with special emphasis on aging and on how rejuvenators are modeled, formulated and used to improve asphalt binders and prevent cracking. The CD-ROM displays figures and illustrations in articles in full color along with a title screen and main menu screen. Each user can link to all papers from the Table of Contents and Author Index and also link to papers and front matter by using the global bookmarks which allow navigation of the entire CD-ROM from every article. Search features on the CD-ROM can be by full text including all key words, article title, author name, and session title. The CD-ROM has Autorun feature for Windows 2000 with Service Pack 4 or higher products along with the program for Adobe Acrobat Reader with Search 11.0. One year of technical support is included with your purchase of this product.

Advanced Testing and Characterization of Bituminous Materials, Two Volume Set

Advanced Testing and Characterization of Bituminous Materials, Two Volume Set PDF Author: Andreas Loizos
Publisher: CRC Press
ISBN: 0203092988
Category : Technology & Engineering
Languages : en
Pages : 1318

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Book Description
Bituminous materials are used to build durable roads that sustain diverse environmental conditions. However, due to their complexity and a global shortage of these materials, their design and technical development present several challenges. Advanced Testing and Characterisation of Bituminous Materials focuses on fundamental and performance testing

8th RILEM International Conference on Mechanisms of Cracking and Debonding in Pavements

8th RILEM International Conference on Mechanisms of Cracking and Debonding in Pavements PDF Author: Armelle Chabot
Publisher: Springer
ISBN: 9402408673
Category : Technology & Engineering
Languages : en
Pages : 735

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Book Description
This book presents the latest advances in research to analyze mechanical damage and its detection in multilayer systems. The contents are linked to the Rilem TC241 - MCD scientific activities and the proceedings of the 8th RILEM International Conference on Mechanisms of Cracking and Debonding in Pavements (MCD2016). MCD2016 was hosted by Ifsttar and took place in Nantes, France, on June 7-9, 2016. In their lifetime, pavements undergo degradation due to different mechanisms of which cracking is among the most important ones. The damage and the fracture behavior of all its material layers as well as interfaces must be understood. In that field, the research activities aims to develop a deeper fundamental understanding of the mechanisms responsible for cracking and debonding in asphalt concrete and composite (e.g. asphalt overlays placed on PCC or thin cement concrete overlay placed on asphalt layer) pavement systems.

PRO 37: 5th International RILEM Conference on Cracking in Pavements – Mitigation, Risk Assessment and Prevention

PRO 37: 5th International RILEM Conference on Cracking in Pavements – Mitigation, Risk Assessment and Prevention PDF Author: C. Petit
Publisher: RILEM Publications
ISBN: 9782912143471
Category : Pavements
Languages : en
Pages : 748

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Book Description


Overlay Tester

Overlay Tester PDF Author: Fujie Zhou
Publisher:
ISBN:
Category : Pavements
Languages : en
Pages : 90

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Book Description
The focus of many asphalt mixture design procedures over the past 10 years has led to the development of stiffer, drier mixtures. However, these mixes are more difficult to construct and are potentially more prone to reflective cracking. In this research the upgraded overlay tester is introduced and proposed as a simple performance test on reflective cracking. The overlay tester can be run on standard size samples, typically 6 in (150 mm) long by 3 in (75 mm) wide by 1.5 in (38 mm) high. These specimens can be prepared from either field cores or from Superpave Gyratory Compactor (SGC) molded specimens. The test is rapid and repeatable, and poor samples fail in minutes. It characterizes both crack initiation and crack propagation properties of asphalt mixtures. Based on repeatability study results, three replicates are recommended for the overlay tester. Sensitivity studies indicate that the overlay tester provides reasonable test results. Increasing asphalt content will significantly improve the reflective cracking resistance of asphalt mixtures. In a series of tests on Texas mixtures, it was determined that aggregate absorption has a major impact on the performance of specimens in the overlay tester. This topic has not received much attention recently but it obviously needs to be investigated. In the lab these highly absorptive aggregates did not severely impact the rutting performance but they had a major impact on cracking life. The effectiveness of the overlay tester was validated by five case studies in Texas. The overlay tester results all correlated well with the field performance. Furthermore, the overlay tester results have good correlations with beam fatigue test results and low temperature performance of asphalt mixtures in the field. A preliminary framework of asphalt overlay mixture designs and associated criteria have been proposed. Based on the framework, two examples of asphalt overlay mixture designs are presented in this report. This framework and the associated criteria are preliminary and they will need further refinement. Finally, a brand new overlay tester has been manufactured and delivered to TxDOTs central lab at the edar Park office. In addition, training for the operation and analysis has been provided.

Tests to Identify Poor Quality Coarse Limestone Aggregates and Acceptable Limits for Such Aggregates in Bituminous Mixes

Tests to Identify Poor Quality Coarse Limestone Aggregates and Acceptable Limits for Such Aggregates in Bituminous Mixes PDF Author: John P. Harris
Publisher:
ISBN:
Category : Aggregates (Building materials)
Languages : en
Pages : 128

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Book Description
The primary objective of this project was to examine the effects of poor quality coarse limestone aggregate on hotmix asphalt performance and to determine how much of the poor quality limestone can be used before adversely affecting performance. A Type C aggregate composed of a high quality limestone from one quarry was blended with soft and absorptive limestone aggregates from two other quarries in different proportions using a PG 64-22 asphalt binder. The individual aggregates were run through Los Angles abrasion, Micro-Deval, magnesium sulfate soundness, specific gravity, and absorption tests. Molded bituminous samples were tested with the Hamburg wheel tracker, dynamic modulus, and the overlay tester.

Journal of the Association of Asphalt Paving Technologists

Journal of the Association of Asphalt Paving Technologists PDF Author:
Publisher:
ISBN:
Category : Asphalt industry
Languages : en
Pages : 1200

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Book Description


Federally Coordinated Program of Highway Research, Development, and Technology. Annual Progress Report. Fiscal Year 1985

Federally Coordinated Program of Highway Research, Development, and Technology. Annual Progress Report. Fiscal Year 1985 PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 704

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Book Description