Author: Randy Clark West
Publisher: Transportation Research Board
ISBN: 0309259134
Category : Pavements, Asphalt
Languages : en
Pages : 162
Book Description
TRB's National Cooperative Highway Research Program (NCHRP) Report 752: Improved Mix Design, Evaluation, and Materials Management Practices for Hot Mix Asphalt with High Reclaimed Asphalt Pavement Content describes proposed revisions to the American Association of State Highway and Transportation Officials (AASHTO) R 35, Superpave Volumetric Design for Hot Mix Asphalt, and AASHTO M 323, Superpave Volumetric Mix Design, to accommodate the design of asphalt mixtures with high reclaimed asphalt pavement contents.
Improved Mix Design, Evaluation, and Materials Management Practices for Hot Mix Asphalt with High Reclaimed Asphalt Pavement Content
Author: Randy Clark West
Publisher: Transportation Research Board
ISBN: 0309259134
Category : Pavements, Asphalt
Languages : en
Pages : 162
Book Description
TRB's National Cooperative Highway Research Program (NCHRP) Report 752: Improved Mix Design, Evaluation, and Materials Management Practices for Hot Mix Asphalt with High Reclaimed Asphalt Pavement Content describes proposed revisions to the American Association of State Highway and Transportation Officials (AASHTO) R 35, Superpave Volumetric Design for Hot Mix Asphalt, and AASHTO M 323, Superpave Volumetric Mix Design, to accommodate the design of asphalt mixtures with high reclaimed asphalt pavement contents.
Publisher: Transportation Research Board
ISBN: 0309259134
Category : Pavements, Asphalt
Languages : en
Pages : 162
Book Description
TRB's National Cooperative Highway Research Program (NCHRP) Report 752: Improved Mix Design, Evaluation, and Materials Management Practices for Hot Mix Asphalt with High Reclaimed Asphalt Pavement Content describes proposed revisions to the American Association of State Highway and Transportation Officials (AASHTO) R 35, Superpave Volumetric Design for Hot Mix Asphalt, and AASHTO M 323, Superpave Volumetric Mix Design, to accommodate the design of asphalt mixtures with high reclaimed asphalt pavement contents.
Superpave Mix Design
Author: Asphalt Institute
Publisher:
ISBN: 9781934154175
Category : Asphalt
Languages : en
Pages : 102
Book Description
Publisher:
ISBN: 9781934154175
Category : Asphalt
Languages : en
Pages : 102
Book Description
Recycling Materials for Highways
Author: National Research Council (U.S.). Transportation Research Board
Publisher: Transportation Research Board National Research
ISBN:
Category : Nature
Languages : en
Pages : 64
Book Description
"This synthesis will be of special interest and usefulness to design engineers, materials technologists, and others seeking information on the potential use of recycled materials in design, construction, rehabilitation, and maintenance of pavements, bases, and other components of the highway system. Detailed information is presented on procedures for pavement recycling."--Avant-propos.
Publisher: Transportation Research Board National Research
ISBN:
Category : Nature
Languages : en
Pages : 64
Book Description
"This synthesis will be of special interest and usefulness to design engineers, materials technologists, and others seeking information on the potential use of recycled materials in design, construction, rehabilitation, and maintenance of pavements, bases, and other components of the highway system. Detailed information is presented on procedures for pavement recycling."--Avant-propos.
A Manual for Design of Hot Mix Asphalt with Commentary
Author:
Publisher: Transportation Research Board
ISBN: 0309155649
Category : Asphalt concrete
Languages : en
Pages : 285
Book Description
Publisher: Transportation Research Board
ISBN: 0309155649
Category : Asphalt concrete
Languages : en
Pages : 285
Book Description
Improved Mix Design, Evaluation, and Materials Management Practices for Hot Mix Asphalt with High Reclaimed Asphalt Pavement Content
Author: Randy Clark West
Publisher:
ISBN: 9780309259132
Category : Pavements, Asphalt
Languages : en
Pages : 164
Book Description
TRB's National Cooperative Highway Research Program (NCHRP) Report 752: Improved Mix Design, Evaluation, and Materials Management Practices for Hot Mix Asphalt with High Reclaimed Asphalt Pavement Content describes proposed revisions to the American Association of State Highway and Transportation Officials (AASHTO) R 35, Superpave Volumetric Design for Hot Mix Asphalt, and AASHTO M 323, Superpave Volumetric Mix Design, to accommodate the design of asphalt mixtures with high reclaimed asphalt pavement contents.
Publisher:
ISBN: 9780309259132
Category : Pavements, Asphalt
Languages : en
Pages : 164
Book Description
TRB's National Cooperative Highway Research Program (NCHRP) Report 752: Improved Mix Design, Evaluation, and Materials Management Practices for Hot Mix Asphalt with High Reclaimed Asphalt Pavement Content describes proposed revisions to the American Association of State Highway and Transportation Officials (AASHTO) R 35, Superpave Volumetric Design for Hot Mix Asphalt, and AASHTO M 323, Superpave Volumetric Mix Design, to accommodate the design of asphalt mixtures with high reclaimed asphalt pavement contents.
Design of a High-binder--high-modulus Asphalt Mixture
Author: G. W. Maupin
Publisher:
ISBN:
Category : Binders (Materials)
Languages : en
Pages : 25
Book Description
Recent studies on long-life flexible pavements indicate that it may be advantageous to design and construct asphalt mixtures comprising the underlying layers in such a manner that very dense mixtures are produced. This will improve not only the fatigue characteristics but also durability through a decrease in air voids. A 19.0 mm mixture was designed and tested at asphalt contents (ACs) higher than the optimum design level. Stiffer binder and recycled asphalt pavement (RAP) were employed to help maintain stiffness in order to prevent instability. The field voids were predicted to decrease approximately 1.0 to 1.5 percent for each 0.4 percent increase in AC, which would improve durability. Flexural stiffness peaked for an 0.5 percent increase in AC, and fatigue life trended upward but needed approximately 1.0 percent additional asphalt for a major beneficial effect. Permeability improved slightly as AC was increased. The researchers think that the Hamburg test would have been more appropriate for this study than the tensile strength ratio test, which indicated no improvement in stripping susceptibility with an increased AC, because it might simulate field conditions better. In addition, the Mechanistic-Empirical Pavement Design Guide Software (Version 0.900) was used to evaluate trial pavement designs with several design alternatives, including varying the binder performance grade, effective binder volume, and air void content to determine the resultant changes in predicted fatigue cracking and rutting of hot-mix asphalt (HMA) layers. This theoretical pavement analysis indicated that increasing the binder content of the HMA intermediate layer beyond the design optimum and increasing the stiffness of the intermediate layer by increasing the high-temperature binder performance grade slightly decreased the predicted fatigue cracking and reduced the rutting of the HMA layers. The analysis also showed that more significant reductions in the predicted fatigue cracking could be realized by increasing the binder content of the HMA base layer slightly beyond the optimum and by reducing the in-place air void content of the HMA base layer. It was recommended that VTRC should further investigate the effects of higher binder contents and lower air voids on the performance of base mixes. Further study of current void criteria to verify optimum pavement performance is also recommended. This project provides a stepping stone to achieve long-lasting perpetual-type flexible pavement. Designs with a high binder content offer the potential to reduce fatigue cracking 20 to 60 percent by incorporating additional asphalt binder and reducing the void content of asphalt base. The use of RAP to maintain the necessary stiffness for high binder contents should provide comparable stiffness to an increasingly expensive PG 70-22 binder for base material. Some effort is taking place in 2007 for reducing voids in base mixes with high RAP content; however, quantification of the economic benefits from that endeavor will be a future goal.
Publisher:
ISBN:
Category : Binders (Materials)
Languages : en
Pages : 25
Book Description
Recent studies on long-life flexible pavements indicate that it may be advantageous to design and construct asphalt mixtures comprising the underlying layers in such a manner that very dense mixtures are produced. This will improve not only the fatigue characteristics but also durability through a decrease in air voids. A 19.0 mm mixture was designed and tested at asphalt contents (ACs) higher than the optimum design level. Stiffer binder and recycled asphalt pavement (RAP) were employed to help maintain stiffness in order to prevent instability. The field voids were predicted to decrease approximately 1.0 to 1.5 percent for each 0.4 percent increase in AC, which would improve durability. Flexural stiffness peaked for an 0.5 percent increase in AC, and fatigue life trended upward but needed approximately 1.0 percent additional asphalt for a major beneficial effect. Permeability improved slightly as AC was increased. The researchers think that the Hamburg test would have been more appropriate for this study than the tensile strength ratio test, which indicated no improvement in stripping susceptibility with an increased AC, because it might simulate field conditions better. In addition, the Mechanistic-Empirical Pavement Design Guide Software (Version 0.900) was used to evaluate trial pavement designs with several design alternatives, including varying the binder performance grade, effective binder volume, and air void content to determine the resultant changes in predicted fatigue cracking and rutting of hot-mix asphalt (HMA) layers. This theoretical pavement analysis indicated that increasing the binder content of the HMA intermediate layer beyond the design optimum and increasing the stiffness of the intermediate layer by increasing the high-temperature binder performance grade slightly decreased the predicted fatigue cracking and reduced the rutting of the HMA layers. The analysis also showed that more significant reductions in the predicted fatigue cracking could be realized by increasing the binder content of the HMA base layer slightly beyond the optimum and by reducing the in-place air void content of the HMA base layer. It was recommended that VTRC should further investigate the effects of higher binder contents and lower air voids on the performance of base mixes. Further study of current void criteria to verify optimum pavement performance is also recommended. This project provides a stepping stone to achieve long-lasting perpetual-type flexible pavement. Designs with a high binder content offer the potential to reduce fatigue cracking 20 to 60 percent by incorporating additional asphalt binder and reducing the void content of asphalt base. The use of RAP to maintain the necessary stiffness for high binder contents should provide comparable stiffness to an increasingly expensive PG 70-22 binder for base material. Some effort is taking place in 2007 for reducing voids in base mixes with high RAP content; however, quantification of the economic benefits from that endeavor will be a future goal.
100 % Recycled Hot Mix Asphalt and the Use of Rejuvenators
Author: Martins Zaumanis
Publisher:
ISBN:
Category :
Languages : en
Pages : 328
Book Description
Abstract: The desire to find more sustainable paving practices as well as the dramatically rising binder costs driven by the growing global demand for paved roads, has led to increased interest of the use of reclaimed asphalt pavement (RAP) in very high amounts. So far the major industry trend has been to develop procedures, invest in technologies and build confidence in mixtures with up to 40 % RAP content. However, a few innovators have refined 100 % recycling technologies over the past four decades to a level where routine production of 100 % recycled hot mix asphalt is in clear sight. Rejuvenators are an integral part of 100 % recycled asphalt production and they can also allow to significantly increase the RAP content for conventionally produced asphalt mixtures. An evaluation of the feasibility of production of 100 % recycled hot-mix asphalt was made and the use of rejuvenators is presented in this study. 100 % recycling is discussed by evaluating ten readily available production technologies along with proposing mix design procedures and identifying best RAP management strategies. A total of eleven different products were evaluated for restoring the RAP binder grade with a definite conclusion that achieving target grade (PG or empirical specification) is possible. In addition a rheological, micromechanical and chemical characterization was performed with select rejuvenators and binders from Strategic Highway Research Program (SHRP) library. To further assess the rejuvenators and feasibility of 100 % RAP recycling a series of 100 % mixture tests were performed that indicated significant improvement in low temperature and fatigue cracking resistance while providing a rut resistant mixture. With the use of some rejuvenators a performance equal to that of reference virgin mix was achieved. Based on these findings of rejuvenator effectiveness a methodology for choice of rejuvenator type and dose was proposed. Finally, a cradle-to-gate analysis of environmental effects was performed which indicated 35 % CO2eq savings per ton of produced 100 % RAP asphalt mixture compared to virgin mix while cost analysis showed at least 50 % savings in material related expenses. A short video summarizing the research is available at http://youtu.be/y-rYvdGiEbY.
Publisher:
ISBN:
Category :
Languages : en
Pages : 328
Book Description
Abstract: The desire to find more sustainable paving practices as well as the dramatically rising binder costs driven by the growing global demand for paved roads, has led to increased interest of the use of reclaimed asphalt pavement (RAP) in very high amounts. So far the major industry trend has been to develop procedures, invest in technologies and build confidence in mixtures with up to 40 % RAP content. However, a few innovators have refined 100 % recycling technologies over the past four decades to a level where routine production of 100 % recycled hot mix asphalt is in clear sight. Rejuvenators are an integral part of 100 % recycled asphalt production and they can also allow to significantly increase the RAP content for conventionally produced asphalt mixtures. An evaluation of the feasibility of production of 100 % recycled hot-mix asphalt was made and the use of rejuvenators is presented in this study. 100 % recycling is discussed by evaluating ten readily available production technologies along with proposing mix design procedures and identifying best RAP management strategies. A total of eleven different products were evaluated for restoring the RAP binder grade with a definite conclusion that achieving target grade (PG or empirical specification) is possible. In addition a rheological, micromechanical and chemical characterization was performed with select rejuvenators and binders from Strategic Highway Research Program (SHRP) library. To further assess the rejuvenators and feasibility of 100 % RAP recycling a series of 100 % mixture tests were performed that indicated significant improvement in low temperature and fatigue cracking resistance while providing a rut resistant mixture. With the use of some rejuvenators a performance equal to that of reference virgin mix was achieved. Based on these findings of rejuvenator effectiveness a methodology for choice of rejuvenator type and dose was proposed. Finally, a cradle-to-gate analysis of environmental effects was performed which indicated 35 % CO2eq savings per ton of produced 100 % RAP asphalt mixture compared to virgin mix while cost analysis showed at least 50 % savings in material related expenses. A short video summarizing the research is available at http://youtu.be/y-rYvdGiEbY.
Hot-mix Asphalt Mixtures
Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 192
Book Description
Publisher:
ISBN:
Category :
Languages : en
Pages : 192
Book Description
Simple Performance Tester for Superpave Mix Design
Author: Ramon Francis Bonaquist
Publisher: Transportation Research Board
ISBN: 0309087821
Category : Medical
Languages : en
Pages : 169
Book Description
The global response to COVID-19 has demonstrated the importance of vigilance and preparedness for infectious diseases, particularly influenza. There is a need for more effective influenza vaccines and modern manufacturing technologies that are adaptable and scalable to meet demand during a pandemic. The rapid development of COVID-19 vaccines has demonstrated what is possible with extensive data sharing, researchers who have the necessary resources and novel technologies to conduct and apply their research, rolling review by regulators, and public-private partnerships. As demonstrated throughout the response to COVID-19, the process of research and development of novel vaccines can be significantly optimized when stakeholders are provided with the resources and technologies needed to support their response. Vaccine Research and Development to Advance Pandemic and Seasonal Influenza Preparedness and Response focuses on how to leverage the knowledge gained from the COVID-19 pandemic to optimize vaccine research and development (R&D) to support the prevention and control of seasonal and pandemic influenza. The committee's findings address four dimensions of vaccine R&D: (1) basic and translational science, (2) clinical science, (3) manufacturing science, and (4) regulatory science.
Publisher: Transportation Research Board
ISBN: 0309087821
Category : Medical
Languages : en
Pages : 169
Book Description
The global response to COVID-19 has demonstrated the importance of vigilance and preparedness for infectious diseases, particularly influenza. There is a need for more effective influenza vaccines and modern manufacturing technologies that are adaptable and scalable to meet demand during a pandemic. The rapid development of COVID-19 vaccines has demonstrated what is possible with extensive data sharing, researchers who have the necessary resources and novel technologies to conduct and apply their research, rolling review by regulators, and public-private partnerships. As demonstrated throughout the response to COVID-19, the process of research and development of novel vaccines can be significantly optimized when stakeholders are provided with the resources and technologies needed to support their response. Vaccine Research and Development to Advance Pandemic and Seasonal Influenza Preparedness and Response focuses on how to leverage the knowledge gained from the COVID-19 pandemic to optimize vaccine research and development (R&D) to support the prevention and control of seasonal and pandemic influenza. The committee's findings address four dimensions of vaccine R&D: (1) basic and translational science, (2) clinical science, (3) manufacturing science, and (4) regulatory science.
Asphalt Pavements
Author: Y. Richard Kim
Publisher: CRC Press
ISBN: 1315736756
Category : Technology & Engineering
Languages : en
Pages : 1966
Book Description
Asphalt Pavements contains the proceedings of the International Conference on Asphalt Pavements (Raleigh, North Carolina, USA, 1-5 June 2014), and discusses recent advances in theory and practice in asphalt materials and pavements. The contributions cover a wide range of topics:- Environmental protection and socio-economic impacts- Additives and mo
Publisher: CRC Press
ISBN: 1315736756
Category : Technology & Engineering
Languages : en
Pages : 1966
Book Description
Asphalt Pavements contains the proceedings of the International Conference on Asphalt Pavements (Raleigh, North Carolina, USA, 1-5 June 2014), and discusses recent advances in theory and practice in asphalt materials and pavements. The contributions cover a wide range of topics:- Environmental protection and socio-economic impacts- Additives and mo