Balanced Mix Design For Surface Asphalt Mixtures
DOWNLOAD
Download Balanced Mix Design For Surface Asphalt Mixtures PDF/ePub or read online books in Mobi eBooks. Click Download or Read Online button to get Balanced Mix Design For Surface Asphalt Mixtures book now. This website allows unlimited access to, at the time of writing, more than 1.5 million titles, including hundreds of thousands of titles in various foreign languages. If the content not found or just blank you must refresh this page
Balanced Mix Design For Surface Asphalt Mixtures
DOWNLOAD
Author : Stacey D. Diefenderfer
language : en
Publisher:
Release Date : 2021
Balanced Mix Design For Surface Asphalt Mixtures written by Stacey D. Diefenderfer and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 2021 with Pavements, Asphalt--Design and construction categories.
In 2017, the Virginia Department of Transportation (VDOT) began to evaluate the feasibility of introducing performance requirements into mix design using the balanced mix design (BMD) method. VDOT has since committed to the implementation of the BMD method in an effort to improve asphalt mixture performance. Through a collaborative effort with industry, VDOT developed two special provisions for use with field trials that use the BMD method to specify as-designed mixture performance. This study documented and evaluated the field trials that were the first applications of these specifications in 2019 to design, produce, and place BMD asphalt mixtures in Virginia. The analyses addressed the application of the BMD concept, production variability, comparisons of mixtures, and differences in specimen test response with and without reheating of the loose mixture for fabrication. Nine mixtures were evaluated from the two field trials; the mixtures incorporated combinations of different reclaimed asphalt pavement (RAP) contents, two binder grades, two recycling agents, and two warm mix asphalt (WMA) additives. Volumetric and gradation analysis was performed on the mixtures. The Cantabro mass loss test (Cantabro test), the indirect tensile cracking test (IDT-CT), and the Asphalt Pavement Analyzer (APA) test were performed on laboratory-produced design specimens and non-reheated and reheated plant-produced, laboratory-compacted specimens. All findings and conclusions are limited to the mixtures evaluated. Based on the test results, mixtures containing a softer binder, WMA additives, 40% RAP, and recycling agents may be designed and produced to meet current BMD performance thresholds and current volumetric properties, gradation, and asphalt content requirements. The laboratory performance test results indicated that for some mixtures, WMA additives and a recycling agent may be expected to provide performance that is equal to or better than the performance of their counterpart mixtures containing only a WMA additive. In addition, results indicated that the evaluated asphalt mixtures containing 40% RAP and softer binders or a recycling agent can be expected to provide performance that is equal to or better than the performance of their counterpart mixtures with 30% RAP. The long-term field and laboratory performance of all of these mixtures needs to be evaluated to verify these early findings. The relationships between performance test results and mixture properties need further study, and improvements in test methods and criteria should be pursued. Based on the outcomes of the study, it is necessary to determine the precision estimates for the Cantabro and APA tests. In addition, the development of different performance criteria for the Cantabro and IDT-CT tests to be applied to non-reheated specimen testing may be necessary. The performance of multiple Cantabro and IDT-CT performance tests for each lot during production may be necessary such that an average test value can be used in BMD quality control, quality assurance, or acceptance practices, because of the variability in individual test results. In light of the lack of failing test results among the mixtures, APA tests may not need to be performed as frequently as Cantabro and IDT-CT tests during production, although this needs to be investigated further.
Balanced Mix Design For Surface Asphalt Mixtures Phase I Initial Roadmap Development And Specification Verification
DOWNLOAD
Author : Stacey D. Diefenderfer
language : en
Publisher:
Release Date : 2021
Balanced Mix Design For Surface Asphalt Mixtures Phase I Initial Roadmap Development And Specification Verification written by Stacey D. Diefenderfer and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 2021 with Pavements, Asphalt--Design and construction categories.
The Virginia Department of Transportation (VDOT), as with many owner agencies, is interested in ways to facilitate the increased durability of asphalt mixtures in an effort to make its roadway network more sustainable, longer lasting, and more economical. The balanced mix design (BMD) method addresses this through the incorporation of performance criteria into mix design and acceptance. VDOT has committed to the implementation of the BMD method in an effort to improve asphalt mixture performance. The purpose of this study was to continue advancing efforts toward VDOT’s implementation of BMD by developing a performance-based mix design roadmap for application in Virginia. The proposed roadmap was developed to provide guidance on the specific needs and activities necessary for VDOT to adopt the BMD concept. A specific need outlined in the roadmap was to validate and/or refine the selected initial performance tests and associated test threshold criteria. To accomplish this, 13 asphalt mixtures were evaluated using performance-measuring laboratory tests. The results of these tests were used to assess the initial performance tests and test threshold criteria selected for BMD use. The proposed roadmap is intended to be an evolving resource for outlining the agenda of activities necessary for implementation of BMD. The roadmap identified specific needs addressed in this study. Based on the results for the mixtures evaluated as part of those needs, the Asphalt Pavement Analyzer (APA) rut test (hereinafter “APA test”); indirect tensile cracking test (IDT-CT) (hereinafter “IDT-CT test”); and Cantabro mass loss test (hereinafter “Cantabro test”) are suitable for continued use in BMD. The current threshold criteria for all three tests were reasonable, based on additional testing and analysis. The study recommends that the roadmap for BMD continue to be refined to provide a clear direction of the activities necessary for implementation and serve as a resource to evaluate progress. VDOT should continue to use the APA, IDT-CT, and Cantabro tests for BMD. The APA and IDT-CT test results should be compared and correlated with those of fundamental rutting and cracking tests, respectively, and with performance predictions obtained from mechanistic-empirical pavement design simulations and field performance for full assurance that test threshold values are appropriate. In addition, the differences in test results attributable to mixture reheating and different specimen types, such as laboratory-compacted specimens and field cores, should be addressed. The study further recommends evaluating the Cantabro, IDT-CT, and APA test results to determine acceptable variability and establish precision statements.
Balanced Mix Design For Surface Mixtures 2020 Field Trials
DOWNLOAD
Author : Stacey D. Diefenderfer
language : en
Publisher:
Release Date : 2023
Balanced Mix Design For Surface Mixtures 2020 Field Trials written by Stacey D. Diefenderfer and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 2023 with Pavements, Asphalt--Design and construction categories.
The Virginia Department of Transportation (VDOT) has been working toward the implementation of balanced mix design (BMD) for several years. During that time, special provisions have been developed to address dense-graded surface mixtures with reclaimed asphalt pavement (RAP) contents up to 30% and with RAP contents of 40% and above. In 2020, five field trials encompassing 12 mixtures were constructed to evaluate BMD mixtures designed and produced in accordance with VDOT’s special provision for surface mixtures with high RAP contents. Typical dense-graded Superpave surface mixtures were used as controls. This study documented and assessed these trials to provide information to evaluate the impact of various RAP contents and additives, production variability, reheating, and binder properties on BMD performance test results. Twelve mixtures were evaluated during the five field trials. The mixtures included combinations of different RAP contents, two binder grades, four recycling agents, and fiber. Volumetric and gradation analysis was performed on the mixtures. The Cantabro mass loss test (Cantabro test), the indirect tensile cracking test (IDT-CT), and the Asphalt Pavement Analyzer (APA) test were performed on laboratory-produced design specimens and non-reheated and reheated plant-produced, laboratory-compacted specimens. All findings and conclusions are limited to the mixtures evaluated. Based on the test results, mixtures containing 35% or greater RAP contents, softer binders, recycling agents, and fiber may be designed and produced to meet current BMD performance thresholds and current volumetric properties, gradation, and asphalt content requirements. It was found that some mixtures that were volumetrically designed under current VDOT specifications met BMD requirements. In addition, the expected trends in mixture performance testing were not always observed, likely due to masking by variability due to specimen fabrication practices or by inherent test variability. Results showed that modest relationships between non-reheated and reheated specimen results for the Cantabro test and IDT-CT were present. In addition, changes due to the use of a softer binder and/or recycling agents were seen in the BMD mixture binders as compared with the control mixture binder. Finally, comparisons of extracted and recovered binders from control and BMD mixtures were found to depend on the binder test under consideration, with different tests indicating differences in expected performance. Based on the outcomes of the study, a testing protocol capable of evaluating the performance of recycling agents used in BMD mixtures is needed. This protocol would provide a means for VDOT to evaluate and accept these materials such that their use in innovative mixtures can be allowed in a manner that preserves the goals of sustainable, longer-lasting, and cost-effective pavements. In addition, efforts should be made to determine the effect of asphalt binder properties on the overall performance of asphalt mixtures with a primary focus on cracking and durability to allow VDOT to specify better-performing binders for use in asphalt mixtures. This would allow for the further optimization of mixture properties that should result in improved mixture performance.
Balanced Mix Design For Surface Mixtures 2021 And 2022 Plant Mix Schedule Pilots
DOWNLOAD
Author : Stacey D. Diefenderfer
language : en
Publisher:
Release Date : 2023
Balanced Mix Design For Surface Mixtures 2021 And 2022 Plant Mix Schedule Pilots written by Stacey D. Diefenderfer and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 2023 with Pavements, Asphalt concrete--Testing categories.
Many state highway agencies are currently exploring a new approach for designing and accepting asphalt mixtures, known as the balanced mix design (BMD) method (hereinafter “BMD”). The Virginia Department of Transportation (VDOT) has made a commitment to adopt BMD to enhance the performance of asphalt mixtures. Since 2018, VDOT has taken incremental steps to phase in the use of BMD in production while addressing concerns expressed by VDOT and the industry. The use of BMD line items in selected 2021 and 2022 contracts has been an important learning opportunity for VDOT and the industry along the path to implementation. This study documented and assessed the 2021 and 2022 maintenance plant mix schedule pilots. The objectives of the study were to provide information on quality control, acceptance testing, and independent assurance testing; analyze the performance properties of reheated mixtures and extracted and recovered binders; and document lessons learned from the process. The analysis addressed several topics, including variability in production and testing and binder characterization and implications for performance. The pilot projects were developed by the VDOT districts using maintenance plant mix schedule contracts. In 2021, approximately 72,000 tons of BMD mixtures were paved on selected routes in 10 maintenance schedules across five districts. In 2022, approximately 222,000 tons of BMD mixtures were paved in 13 maintenance schedules distributed across all nine VDOT districts, with at least one BMD contract executed per district. The Cantabro mass loss test, the indirect tensile cracking test (IDT-CT), the Asphalt Pavement Analyzer rut test, and the indirect tensile test at high temperature (IDT-HT) were performed on laboratory-produced design specimens and non-reheated and reheated plant-produced, laboratory-compacted specimens. Basic and advanced binder testing and analysis were conducted on extracted and recovered binders from selected samples of the mixtures. Based on the test results, the successful outcomes observed during the pilot projects in 2021 and 2022 clearly demonstrated the efficacy of applying BMD to surface mixtures (SMs) with A and D designations. Moreover, there was a decrease in variability in test results from 2021 to 2022, showcasing the benefits derived from training and experience in BMD testing performance. Notably, it was found that the source and formulation of the virgin binder used, along with the properties of the aged binder in reclaimed asphalt pavement (RAP) stockpiles, contributed to substantial variations in binder properties and affected the expected performance of the produced mixtures. The study recommends that (1) efforts be pursued toward full implementation of BMD in Virginia for SMs with A and D designations, as supported by VDOT’s 2024 BMD special provision; (2) a comprehensive ruggedness study focusing on the refinement of specimen preparation and test methods for the IDT-CT and IDT-HT be initiated to assess key factors that demand stricter control and additional guidance during specimen preparation for the IDT-CT and IDT-HT; and (3) a comprehensive study to assess the relationships between the properties of virgin and RAP asphalt binders and those of the corresponding asphalt mixtures be conducted.
Functional Characteristics Of Dense Graded Asphalt Surface Mixtures
DOWNLOAD
Author : Ilker Boz
language : en
Publisher:
Release Date : 2023
Functional Characteristics Of Dense Graded Asphalt Surface Mixtures written by Ilker Boz and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 2023 with Pavements, Asphalt--Design and construction categories.
As asphalt mix design criteria evolve beyond prescriptive to performance-based specifications, traditional limits may be challenged in the pursuit of material durability. As designers explore these limits, it is important to understand how basic design criteria ultimately affect the comfort and safety of the public who travels over these mixtures. This study assessed the short-term functional (surface) characteristics of pavements constructed using dense-graded asphalt surface mixtures designed with the balanced mix design (BMD) methodology as compared to counterpart mixtures designed using the existing design methodology (Superpave). Another objective of this study was to establish a functional performance baseline for the Virginia Department of Transportation’s (VDOT) BMD trial mixtures constructed in the 2019 through 2021 construction seasons in terms of friction and macrotexture. This study also sought to define a potential empirical relationship to link mixture volumetric properties to the surface characteristics of asphalt mixtures in terms of macrotexture. In this effort, 52 different field projects encompassing pairs of BMD and control mixtures with service lives ranging from 0.1 to 2.8 years were surveyed for friction, macrotexture, and pavement roughness. Descriptive statistics and parametric statistical techniques were used to identify systematic trends or differences in the functional characteristics of the pavements. The results showed that application of the BMD methodology resulted in slight changes in volumetric properties and gradations of asphalt mixtures, but these changes mostly fell within the production variability limits of conventionally designed mixtures. The results also showed that BMD mixtures, on average, provided similar or better friction, macrotexture, and smoothness characteristics. In addition, similar or more uniform texture characteristics were, on average, obtained for the surfaces receiving BMD mixtures, potentially indicating better construction uniformity. Further, an empirical model incorporating production volumetric and gradation properties was developed to predict macrotexture. The study concludes that based on the results from the sites evaluated, use of the BMD methodology yields similar or better functional surface characteristics when compared to those of conventionally designed mixtures. The study recommends the continuation of BMD implementation, as the functional characteristics are either preserved or enhanced with the use of the BMD methodology. Further, the study recommends the assessment of existing and future BMD projects and continued collaboration among VDOT’s Maintenance Division, Materials Division, and Traffic Operations Division on developing a friction and texture management framework
Simple And Practical Tests For Rutting Evaluation Of Asphalt Mixtures In The Balanced Mix Design Process
DOWNLOAD
Author : Ilker Boz
language : en
Publisher:
Release Date : 2023
Simple And Practical Tests For Rutting Evaluation Of Asphalt Mixtures In The Balanced Mix Design Process written by Ilker Boz and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 2023 with Asphalt-Testing categories.
The Virginia Department of Transportation (VDOT) is currently using the asphalt pavement analyzer (APA) as a testing tool to screen the rutting potential of asphalt mixtures as part of its balanced mix design (BMD) method. However, the cost and availability of APA equipment in VDOT and contractor laboratories and the speed of testing are main barriers to the routine use of APA in the BMD process, especially during the production of asphalt mixtures. The existence of alternative tests that are simple, practical, and performance indicative can help facilitate the implementation of BMD into practice. The monotonic loading tests (hereinafter “monotonic tests”) have been proposed to address the need for simpler tests. This study was undertaken to assess the feasibility of using monotonic tests as a screening tool to evaluate the rutting potential of dense-graded asphalt surface mixtures as part of the BMD initiative in Virginia. In this effort, three monotonic tests, the indirect tensile at high temperature (IDT-HT) test, rapid rutting (RR) test, and Marshall stability and flow (MS) test, identified from the literature, were evaluated using 17 plant-produced asphalt mixtures with “A” and “D” designations. The results were used to assess the monotonic tests and the APA test relative to each other through several performance metrics and correlations with fundamental rutting tests and mechanistic-empirical–based simulations. The results were also used to develop performance threshold criteria for the considered tests. The results showed that the IDT-HT and RR tests can be used to screen the rutting potential of asphalt mixtures meeting VDOT mixture volumetric and gradation requirements for the A and D mixtures. The initial performance criteria for the IDT-HT and RR tests were established for these mixtures. Based on the results, the IDT-HT test was found to be the most suitable alternative test to the APA test. The study recommends using the IDT-HT test as part of the BMD initiative with a corresponding minimum strength of 133 kPa as a performance criterion based on the testing conditions used in this study. Implementation of traffic-based performance criteria for the A and D mixtures should be explored, as the current practice does not differentiate the performance between these mixtures. The results of the IDT-HT, RR, and the APA tests should be compared and correlated with those from fundamental rutting tests and with performance predictions obtained from mechanistic-empirical pavement design simulations using a larger number of mixtures to verify the findings of this study. In addition, the results should be compared to field performance results for full assurance that the implemented tests and associated threshold values are appropriate. Fine-tuning the testing process for the IDT-HT, RR, and APA tests and establishing precision estimates and statements are necessary for proper quality assurance practices. The study further recommends hands-on training and demonstration of the tests being considered by VDOT as part of the BMD implementation.
Nebraska Balanced Mix Design Phase I
DOWNLOAD
Author : Farzad Yazdipanah
language : en
Publisher:
Release Date : 2023
Nebraska Balanced Mix Design Phase I written by Farzad Yazdipanah and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 2023 with categories.
Balanced mix design (BMD) is an alternative concept for designing asphalt mixtures that mainly focuses on performance of mixtures rather than only volumetric analysis. Using this concept, it would be possible to account for the incorporation of recycled asphalt mixtures, warm technology, polymers, rejuvenators, and other foreign additives, as well as external effective factors on the mix design such as environmental effects. This project sought to investigate performance-based methodologies for the asphalt mix design by taking a step to develop a preliminary Nebraska BMD framework. With that, selection of appropriate performance tests, finding a functional laboratory aging protocol, and defining performance test criteria were the main long-term goals developed in this phase of study. To this end, three main types of distresses were taken into consideration (rutting, fatigue cracking, and moisture susceptibility), and a set of performance tests including well-established tests (Hamburg Wheel Track (HWT), Illinois Flexibility Index Test (I-FIT), Tensile Strength Ration (TSR)) and surrogate tests (IDEAL-RT, HT-IDT, G-stability, IDEAL-CT) were selected to capture these distresses on two types of high-performance commonly used asphalt mixtures in Nebraska (SLX and SPR). For the fatigue cracking analysis, long-term aging conditioning was conducted using two common aging protocols (NCHRP 09-54 and NCAT). Three types of data were utilized in this study including laboratory performance test results for the lab-compacted and field core specimens, as well as field data based on pavement surface condition monitoring. The validity of the surrogate performance tests was accomplished not only by correlating the field core results with field condition data, but also with correlating every individual surrogate test result to that of a well-established test. Further, the sensitivity, practicality, cost-effectiveness, and variability of different tests were assessed using statistical
Development Of A Balanced Mix Design Method In Oregon
DOWNLOAD
Author : Erdem Coleri
language : en
Publisher:
Release Date : 2020
Development Of A Balanced Mix Design Method In Oregon written by Erdem Coleri and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 2020 with Binders (Materials) categories.
According to recent surveys conducted with state Department of Transportations (DOTs) and asphalt contractors, commonly used asphalt mixture properties are not directly reflecting the long-term performance of asphalt mixtures. In addition, there are several new additives, polymers, rubbers, and high-quality binder types incorporated into asphalt mixtures today. Volumetric mixture design methods are not capable of capturing the benefits of using all these new technologies on asphalt mixture performance. Furthermore, the interaction of virgin binders with reclaimed asphalt pavement (RAP) mixtures with high binder replacement contents and the level of RAP binder blending into the asphalt mixture are still not well understood. Due to all these complications related to the more complex structure of today's asphalt mixtures, simple volumetric evaluations to determine the optimum binder content may not result in reliable asphalt mixture designs. Two volumetrically identical mixtures may provide completely different rutting and cracking performance according to laboratory tests. For all these reasons, in this study, a procedure to incorporate performance tests for rutting and cracking (with a new long-term aging protocol developed in this study) into current asphalt mixture design methods was developed to be able to validate or revise the optimum binder content determined by the volumetric mix design method. Developed balanced mix design method is expected to improve the long-term performance of asphalt-surfaced pavements in Oregon.
Balanced Design Of Asphalt Mixtures
DOWNLOAD
Author : David E. Newcomb
language : en
Publisher:
Release Date : 2018
Balanced Design Of Asphalt Mixtures written by David E. Newcomb and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 2018 with Pavements, Asphalt categories.
A balanced mix design (BMD) sets a maximum asphalt content based on the rutting criterion and a minimum asphalt content based on cracking criterion. This project developed a BMD framework for the Minnesota Department of Transportation (MnDOT) and used it to evaluate materials from four Minnesota projects using the Illinois Flexibility Index, the IDEAL-CTAL-CT-CT Cracking Test Index by the Texas A&M Transportation Institute, and the Disk-shaped Compact Tension test for cracking and the Hamburg Wheel Tracking test for rutting. For the four test mixtures, the performance tests and the BMD procedure were successful in distinguishing the influence of asphalt content on cracking resistance and rutting resistance. There was fairly good agreement among the cracking tests for the asphalt content and only a slight deviation from volumetric asphalt content in most cases. The cracking and rutting performance criteria need to be refined for different applications based on characteristics such as climate, lift thickness, traffic level, and placement within the pavement structure.
Designing Stone Matrix Asphalt Mixtures For Rut Resistant Pavements
DOWNLOAD
Author : E. Ray Brown
language : en
Publisher: Transportation Research Board
Release Date : 1999
Designing Stone Matrix Asphalt Mixtures For Rut Resistant Pavements written by E. Ray Brown and has been published by Transportation Research Board this book supported file pdf, txt, epub, kindle and other format this book has been release on 1999 with Asphalt categories.
Part 1: Summary of research results; Part 2: Mixture design method, construction guidelines, and quality control/quality assurance procedures