The state of bridge infrastructure in the United States is mediocre in respect to condition, capacity, funding, future need, and innovation [ASCE 2017]. Fifty percent of existing bridges are older than a half-century, and nearly nine percent of them are structurally deficient [FHWA 2017]. Hence, implementing innovative methods to retrofit and upgrade bridges with limited funding and the least environmental footprint is an essential priority for bridge infrastructure. Application of expanded shale, clay and slate (ESCS) aggregate contributes to sustainability and resilience of bridge infrastructure through reduction of structural demands, extending service life, and other performance measures. These contributions resulted in prestigious awards and recognitions by ASCE OPAL, AISC NSBA, and ISI Envision for Bayonne and Williams Creek bridges in 2020.
The Bayonne Bridge replacement project won the Outstanding Civil Engineering Achievement (OCEA) award at the OPAL (Outstanding Projects and Leaders) Gala by American Society of Civil Engineers (OPAL 2020). The project utilized structural lightweight concrete using ESCS to reduce structural demands on the bridge. The lower demand allowed the new deck to be constructed while the existing deck remained open to traffic (ESCSI 2017). Further, application of ESCS allowed the project to provide higher clearance for larger ships and add bike-friendly ADA-compliant accessible routes without disturbing the image of this historic landmark. The Bayonne Bridge Navigational Clearance Program earned an Envision Silver award for sustainability (ISI 2019).
The Williams Creek Bridge replacement project involved replacements of the existing single-lane Shoup Bridge nearly five miles south of Salmon, Idaho with a two-lane bridge to facilitate access to the Salmon Challis National Forest as well as recreational and commercial points of interest (ESCSI 2018). The project took advantage of internally-cured concrete using fine lightweight ESCS to enhance the durability and extend the service life of the bridge deck (ESCSI 2020). The Williams Creek (Shoup) Bridge won the merit award for medium span class from American Institute of Steel Construction (NSBA 2020).