Construction of asphalt pavements, which are the most common type of pavements in the world, is heavily reliant on various non-renewable resources such as aggregates and petroleum-based asphalt binders. A crucial step toward developing a sustainable transportation infrastructure is reducing this dependency and shrinking the environmental footprint of the industry by replacing asphalt binders with alternative sustainable materials. Production of asphalt binders is known as the most energy demanding process involved in asphalt pavement construction, consuming over 40% of the energy in the industry. This results in release of substantial quantities of greenhouse gases, the main contributor toward climate change. This, along with steady increase in the price of asphalt binder due to higher demand, lower production and diminishing resources, warranted various studies to find sustainable alternatives for asphalt binders. One potential group of materials for this purpose are bio-binders. Bio-binders are made through processing of bio-oils, which are produced through thermochemical liquefaction of various biomass feedstocks. Due to variability of the source biomass, these bio-binders have varying properties, and require in-depth investigations. Majority of studies in this field have reported that bio-binders and their blends with asphalt binders (bio-asphalts) suffer from severe aging, hence, recommended limiting the replacement ratio of these materials to minimize the impact of this problem.This study was aimed toward evaluating the possibility of replacing substantial quantities of asphalt binder with bio-binders, and involved conducting thorough physical, rheological, chemical and performance evaluation of bio-binders and bio-asphalts. Four different bio-binders sourced from switchgrass, oakwood, and two blends of pine wood were used in this study. Results confirmed that all bio-asphalts are experiencing severe aging, which results in deterioration of the low-temperature properties of bio-asphalts. Hence, a practical method was sought for improving the low-temperature properties of bio-asphalts. This method, which was based on adjusting the properties of the aged bio-asphalts to match with the properties of aged base asphalt binder, involved addition of small quantities of rejuvenator to the bio-asphalts, and was found to be able to successfully offset the changes in properties of the bio-asphalts due to severe aging of the bio-binders. While having comparable long-term aged properties, the rejuvenator-modified bio-asphalts were found to be significantly softer than the base binder, which could be translated to lower construction and compaction temperatures, further reducing the energy demand of the asphalt pavement construction.Chemical experiments revealed that the upgrading process reduced the water and light-weight components content of the bio-oil significantly. Bio-binders were found to have significantly different chemical composition compared with conventional asphalt binders, having high water, low weight and polar molecule content. This significant difference between the chemical properties resulted in lack of chemical interaction between the two materials, hence, bio-asphalts were found to be a two-phased material, consisting of small droplets of bio-binders physically dispersed within the asphalt binder medium.Existence of free bio-binder particles can be problematic, as the bio-binders and asphalt binders have significantly different aging susceptibility. As the aged bio-binders were found to have highly different properties compared with asphalt binders, these aged droplets of bio-binder can affect the performance of mixtures made with bio-asphalts. Hence, a comprehensive mixture study was conducted to evaluate the performance of bio-asphalts in mixtures. Results of the study showed that bio-asphalt mixtures were in general showing less desirable properties at the same temperatures compared with the mixture made with conventional asphalt binders. This inferior performance was partly due to the softer nature of bio-asphalts compared with the base asphalt binder at the same temperatures. The softer nature of the bio-asphalt was caused by inclusion of rejuvenator to enhance the low-temperature properties of bio-asphalts. However, it was found that the mixtures made with bio-asphalts with no rejuvenator were less flexible compared with the control mixtures. This loss of flexibility can be due to the presence of severely aged bio-binder droplets in bio-asphalts, weakening the bond between aggregates and the bio-asphalts.Additional steps are required to facilitate the chemical interaction between asphalt binder and bio-binders, to eliminate the two-phase nature of bio-asphalts, which in turn can result in bio-asphalts with higher resistance to aging and better mixture performance.

The urgent need for infrastructure rehabilitation and maintenance has led to a rise in the levels of research into bituminous materials. Breakthroughs in sustainable and environmentally friendly bituminous materials are certain to have a significant impact on national economies and energy sustainability. This book will provide a comprehensive review on recent advances in research and technological developments in bituminous materials. Opening with an introductory chapter on asphalt materials and a section on the perspective of bituminous binder specifications, Part One covers the physiochemical characterisation and analysis of asphalt materials. Part Two reviews the range of distress (damage) mechanisms in asphalt materials, with chapters covering cracking, deformation, fatigue cracking and healing of asphalt mixtures, as well as moisture damage and the multiscale oxidative aging modelling approach for asphalt concrete. The final section of this book investigates alternative asphalt materials. Chapters within this section review such aspects as alternative binders for asphalt pavements such as bio binders and RAP, paving with asphalt emulsions and aggregate grading optimization. - Provides an insight into advances and techniques for bituminous materials - Comprehensively reviews the physicochemical characteristics of bituminous materials - Investigate asphalt materials on the nano-scale, including how RAP/RAS materials can be recycled and how asphalt materials can self-heal and rejuvenator selection

Green and Intelligent Technologies for Sustainable and Smart Asphalt Pavements contains 124 papers from 14 different countries which were presented at the 5th International Symposium on Frontiers of Road and Airport Engineering (IFRAE 2021, Delft, the Netherlands, 12-14 July 2021). The contributions focus on research in the areas of "Circular, Sustainable and Smart Airport and Highway Pavement" and collects the state-of-the-art and state-of-practice areas of long-life and circular materials for sustainable, cost-effective smart airport and highway pavement design and construction. The main areas covered by the book include: • Green and sustainable pavement materials • Recycling technology • Warm & cold mix asphalt materials • Functional pavement design • Self-healing pavement materials • Eco-efficiency pavement materials • Pavement preservation, maintenance and rehabilitation • Smart pavement materials and structures • Safety technology for smart roads • Pavement monitoring and big data analysis • Role of transportation engineering in future pavements Green and Intelligent Technologies for Sustainable and Smart Asphalt Pavements aims at researchers, practitioners, and administrators interested in new materials and innovative technologies for achieving sustainable and renewable pavement materials and design methods, and for those involved or working in the broader field of pavement engineering.

A dozen papers from a December 1993 symposium in Dallas/Fort Worth, Texas. Among the topics are why the new proposed rheological properties of asphalt binders are required and how they compare to conventional properties, the development and use of the SHRP direct tension specification test, oxidatio

This volume on “Advancement in the Design and Performance of Sustainable Asphalt Pavements” includes a collection of research and practical papers from an international research and technology activities on Mixture Design Innovation, Structural Pavement Design, Advancement in Production and Construction, Climate Changes and Effects on Infrastructure, Green Energy, Technology and Integration. The volume constitutes an important contribution in view of the urgent need to develop materials, designs, and practices to ensure the sustainability of transportation infrastructure. This volume is part of the proceedings of the 1st GeoMEast International Congress and Exhibition on Sustainable Civil Infrastructures, Egypt 2017.

Asphalt modification is an important area in the development of new road and pavement materials. There is an urgent demand for road materials that can minimize fracture at low temperatures and increase resistance to deformation at high temperatures. The function of asphalt is to bind aggregate to protect it from water and other harmful agents. In the beginning asphalt was ideal for this purpose, but recently traffic loads have increased and environmental factors have deteriorated more rapidly than before. Asphalt is a byproduct of crude oil in the refining process, and it is considered a complex heterogeneous mixture of hydrocarbons. Asphalt modification has become an important research area, using several methods and new materials as modifiers.

This volume contains the Proceedings of the RILEM TC 252-CMB International Symposium on the Chemo-Mechanical Characterization of Bituminous Materials. The Symposium was attended by researchers and practitioners from different fields presenting the latest findings in the chemical, mechanical, and microstructural characterization of bituminous materials. The book offers new and cutting edge papers on innovative techniques for the characterization of bituminous materials, gaining new insights into current issues such as effects of aging, moisture, and temperature.

Asphalt is a complex but popular civil engineering material. Design engineers must understand these complexities in order to optimize its use. Whether or not it is used to pave a busy highway, waterproof a rooftop or smooth out an airport runway, Asphalt Materials Science and Technology acquaints engineers with the issues and technologies surrounding the proper selection and uses of asphalts. With this book in hand, researchers and engineering will find a valuable guide to the production, use and environmental aspect of asphalt. - Covers the Nomenclature and Terminology for Asphalt including: Performance Graded (PG) Binders, Asphalt Cement (AC), Asphalt-Rubber (A-R) Binder, Asphalt Emulsion and Cutback Asphalt - Includes Material Selection Considerations, Testing, and applications - Biodegradation of Asphalt and environmental aspects of asphalt use