Asphalt mix design has always been considered a balance of rutting resistance and durability. The conventional Superpave mix design system targets 4% air voids during design and is referred to in this circular as Superpave4. The Superpave5 concept is a modification to the conventional Superpave4 approach. Transportation Research Circular E-C300: Superpave5: How Increasing Air Voids Can Improve Asphalt Pavement Durability , from the Transportation Research Board, captures information exchanged during the ...

Asphalt mix design has always been considered a balance of rutting resistance and durability. The conventional Superpave mix design system targets 4% air voids during design and is referred to in this circular as Superpave4. The Superpave5 concept is a modification to the conventional Superpave4 approach. Transportation Research Circular E-C300: Superpave5: How Increasing Air Voids Can Improve Asphalt Pavement Durability , from the Transportation Research Board, captures information exchanged during the ...

The most inherent advantage of a smooth pavement surface is its reduced noise levels compared to a pavement that is not smooth, but beyond the noise impacts there lies indirect and direct benefits that people gain from a smooth pavement. Transportation Research Circular E-C297: Concrete Pavement Smoothness: 2023 Workshop , from the Transportation Research Board, was developed from presentations made during the 102nd TRB Annual Meeting in a workshop titled "Concrete Pavement Smoothness."

Federal laws and rules require performance standards to be implemented to enhance stewardship of the transportation infrastructure and foster greater innovation in delivering a resilient transportation system, including the life of pavement systems, that supports prosperity and opportunity. Transportation Research Circular E-C296: Foundation Design and Construction for 100-Year Pavement Systems documents the presentations and discussions from two workshops held during the 2024 and 2023 TRB Annual Meeting...

Asphalt mixture mechanical tests (such as Hamburg Wheel-Track, Asphalt Pavement Analyzer, Indirect Tensile Cracking) are growing in use by numerous state departments of transportation (DOTs) as part of their standard material specifications to complement volumetric properties and help ensure satisfactory asphalt mixture performance. Transportation Research Circular E-C294: Adjustment to Asphalt Mixtures to Meet Performance Testing Requirements and Allow Innovations , from the Transportation Research Boar...

Asphalt pavement stakeholders are working toward a common goal of net-zero emissions by 2050 and incorporating the use of technologies and tools to rationally quantify the environmental impacts of asphalt pavement materials and construction alternatives. Transportation Research Circular E-C295: Day-to-Day Practices to Reduce the Carbon Footprint of Asphalt , from the Transportation Research Board, summarizes a session called "Day-to-Day Practices to Reduce the Carbon Footprint of Asphalt," which was hel...

The design of asphalt mixtures for use in infrastructure applications has generated significant research and focus over recent years. Recent advancements in mechanical testing of asphalt mixtures, often referred to as "performance tests," brought to the asphalt community the concept of Balanced Mix Design (BMD) and the use of these tests to augment or go beyond volumetric design. TR Circular E-C293: Listen Up! Challenges for Asphalt Balanced Mixture Design Implementation and How the Research Community Ca...

Monitoring travel on the nation's roadways is crucial for understanding the dynamics of the U.S. transportation system. This involves both broad assessments, such as calculating annual average daily traffic to report on vehicle miles traveled, and detailed analyses, like examining freeway operations on a minute-by-minute basis. TR Circular E-C292: Advancing Highway Traffic Monitoring Through Strategic Research: 2024 Update , from the Transportation Research Board, is a collaborative effort of over 60 spe...

Dielectric Profiling Systems and Paver Mounted Thermal Profiling can be used to advance pavement quality measurement of the entire mat from a limited number of random post-construction measurements to near-continuous measurements in real time during construction. TR Circular E-C290: Implementing Dielectric Profiling Systems for Real-Time Quality Control , from the Transportation Research Board, presents a summary of a workshop that took place during the 2023 Transportation Research Board Annual Meeting i...

The increasing volume of plastic waste generated each year is a global problem—one that has been magnified following the 2017 passing of China’s Operation National Sword policy that ended the import of waste plastics into the country effective January 2018. Rightfully, this action has awakened a renewed effort to reduce and recycle plastic waste and asphalt pavements have been identified as a potential new end-market opportunity. TR Circular E-C291: Recycling Waste Plastics in Asphalt Pavements , from th...