Monitoring and Documentation of SMA Project on I-90

Stone mastic (or matrix) asphalt (SMA) provides a deformation-resistant, durable surfacing material suitable for heavily trafficked roads. WSDOT does not often use SMA, but this spring it is applying SMA on I-90 in Eastern Washington. This project is documenting the construction project. Researchers are following the project from start to finish and chronicling everything related to it, from the aggregate and other materials used through the laydown of the asphalt. Documentation of the project will help WSDOT in carrying out similar SMA pavement projects in the future.

Principal Investigators:
Balasingham Muhunthan, Civil and Environmental Engineering, WSU
Haifang Wen, Civil and Environmental Engineering, WSU

Sponsor: WSDOT
WSDOT Technical Monitor: Kim Willoughby
WSDOT Project Manager: Jon Peterson
Scheduled completion: December 2019

Development of a Protocol to Maintain the Winter Mobility of Different Classes of Pervious Concrete Pavement Based on Porosity

The use of pervious concrete pavements is recommended by several U.S. environmental agencies as a Best Management Practice for stormwater control, which has increased their application to streets, parking lots, bike lanes, and sidewalks across the Pacific Northwest. However, with increased use of pervious concrete in areas with adverse winter weather, proper ice and snow control protocols must be developed to ensure the mobility and safety of drivers and pedestrians on pervious concrete installations. In a previous project, the researchers determined that the friction performance of pervious concrete pavement surfaces from one mixture design outperformed that of traditional concrete pavements in dry, wet, and icy conditions.  This project will extend the scope of laboratory and field testing to include a wide range of mixtures and installations. The goal is to ensure mobility on various classes of pervious concrete pavements all year around.

Principal Investigator: Somayeh Nassiri, Civil and Environnmental Engineering, WSU
Sponsor: PacTrans
Scheduled completion: February 2020

RAP Reset: Responsibly Optimizing Recycled Materials Use in HMA and Pavement Performance Life

Concerns with the performance of hot mix asphalt (HMA) that contains recycled materials have recently become the focal point of the asphalt industry. Recycled materials used in HMA in Washington may include reclaimed asphalt pavement (RAP), reclaimed asphalt shingles (RAS), and recycled engine oil bottoms (REOB). In the late 2000’s recycled materials use increased as the economy crashed, market competition increased and margins decreased, and virgin asphalt binder cost increased significantly. However, the impacts of that increased usage are beginning to be better understood, and transportation agencies are determining that the durability of HMA may have been compromised as a result. The primary objective of this project is to increase the understanding of the effects of recycled materials on HMA performance and durability to enhance WSDOT’s HMA materials selection, mix design process, and standard specifications. The results are intended to help WSDOT modify its overall recycled materials strategy so that it is informed by current national best practices, takes into account observable local issues and test results, and leads to more durable HMA pavements.

Principal Investigator: Steve Muench, Civil and Environmental Engineering, UW
Sponsor: WSDOT
WSDOT Technical Monitor: Joe DeVol
WSDOT Project Manager: Jon Peterson
Scheduled Completion: December 2019

Improvement to the LTTP Traffic Database

The FHWA’s Long-Term Pavement Performance (LTPP) program makes the world’s largest pavement performance database available annually to the public. However, a number of LTPP test sections are missing traffic data or have unreliable traffic parameters that limit the ability of researchers to use those sites in analyses that require traffic load as an input. In addition, the traffic data in the LTPP Standard Data Release can be complex and difficult to navigate. This project is designed to improve the LTPP database, both by significantly improving the traffic load data incorporated in it and by making it easier for pavement researchers to select the traffic data they need for specific analyses. As a subcontractor to Applied Research Associates (ARA), UW researchers are helping to identify the gaps and major limitations in the traffic data in the current LTPP Standard Data Release, provide traffic estimates for the LTPP sites with missing or questionable traffic data in the form of computed parameters tables, and provide guidance to help users quickly select the most appropriate LTPP test sites and traffic statistics for their pavement analyses.

Principal Investigator: Mark E. Hallenbeck, Civil and Environmental Engineering, UW

Applied Research Associates

ARA Technical Monitor: O. Selezneva
Scheduled completion: February 2019

Novel Development of Bio-Based Binder for Sustainable Construction

Hot mix asphalt (HMA) consists of aggregate particles bonded together by asphalt binder at high heat. Petroleum-based asphalt is widely used in road and other infrastructure construction.  However, high oil prices and tight asphalt supply have recently doubled asphalt prices. Industries are therefore seeking an alternative binder for HMA. Alternative binders such as fly ash, silica fume, and ground granulated blast-furnace slag have been used, as have sulfur, coal tar, manure-based bio-oil, or plant-based bio-oil, but each raises concerns about price and/or performance. This project is seeking to develop a 100 percent waste cooking oil-based bioasphalt modified with lignin-derived epoxy (LEP). Both waste cooking oil and lignin (found in plant tissues and burned in pulp mills) are byproducts. The resulting bioasphalt will have comparable or superior material properties to those of traditional petroleum-based binders, resistant to fatigue, rutting, thermal cracking, and moisture susceptibility. And being based on industry byproducts, it will reduce the need to procure virgin materials, reduce energy consumption, and reduce greenhouse gas emissions, as well as cost significantly less than petroleum-based asphalt.

Principal Investigators:
Balasingam Muhunthan, Civil and Environmental Engineering, WSU
Jinwen Zhang, School of Mechanical and Materials Engineering, WSU
Michael Wolcott, Civil and Environmental Engineering, WSU
Junna Xin, Composite Materials and Engineering Center, WSU
Kun Zhang, Civil and Environmental Engineering, WSU

Sponsor: FHWA
FHWA Technical Contact: D. Confer
FHWA Project Manager: J. Youtcheff
Scheduled completion: August 2018