CONCRETE TODAY IV SPECIAL ADVERTISING SECTION Emphasizing Durability, Performance and Carbon Reduction From high-performance mixes to low-carbon processes, the essence of the most widely used material in the world continues to evolve. One of the hottest areas of advancement and investment is ultra-high performance concrete (UHPC), a concrete technology that has been around for several decades. According to one market study, it’s a market that was already measured at $388.3 million in 2022 and is expected to grow to $574.7 million by 2029. The reasons are clear. While it requires more cost upfront, the result is far superior to regular concrete, according to organi-zations such as the Federal Highway Administration (FHWA). In fact, the agency notes that UHPC, which is an FHWA Every Day Counts supported innovation, is proving to be easier to place into formwork, much stronger, less permeable and able to maintain its load-carrying capacity even after overloads or in aggressive environments. Further, its high compressive and tensile strengths and enhanced dura-bility properties lengthen the design life of structures such as bridges and precast concrete deck panels. And another benefit of UHPC is that it’s considered the lowest low-carbon concrete material in the service process—a characteristic that is increasingly important across the industry. One current example of UHPC at work is the Southern Avenue Bridge over the Suitland Parkway in Wash-ington, D.C. This bridge, partially funded by a $1-million federal grant, is believed to be the first in the District to use UHPC. FHWA provided another $1-million grant to the District of Columbia Dept. of Transporta-tion (DOT) to use UHPC as a way to prolong the life of a bridge and reduce the environmental and social impacts of future major repairs or reconstruc-tion. Located in New Castle, Del., the Delaware Memorial Bridge will include a UHPC overlay along the New Jersey-bound span. According to the Delaware River and Bay Authority, this will be the first use of UHPC on a suspension bridge in the world. Studies funded by the agency show that the UHPC application has lower initial and life-cycle costs; a shorter, more flexible construction schedule, and prevents salt intrusion when compared to a full deck replacement program. The UHPC overlay is expected to last more than 70 years. The bridge overlay is on track for completion by the end of November 2023. In Oklahoma, FHWA provided a $839, 807 grant to Oklahoma DOT, which will use UHPC to repair and replace 18 expansion joints and 18 fixed joints of the northbound and southbound I-35 Cimarron Overflow bridges. One of the challenges to UHPC, besides cost, is the varied mixing proce-dures and pouring and curing regimes. To better support the engineering community, the American Association of State Highway and Transporta-tion Officials’ (AASHTO) Concrete Bridge Design subcommittee, working with FHWA and industry partners, has developed the Guide Specification for Structural Design with UHPC. Researchers at FHWA’s Turner-Fair-bank Highway Research Center assisted AASHTO in the development of the Guide Specification. The AASHTO Committee on Bridges and Structures approved the Guide Specification during their annual meeting in May 2023. AASHTO is expected to publish the document in late 2023 or early 2024. Much of FHWA’s work on the topic, as well as design examples that assist users in grasping the concepts under-lying the Guide Specification, will be covered in FHWA’s forthcoming report titled Structural Design with Ultra-High Performance Concrete (FHWA-HRT-23-077). Publication of the FHWA report is expected in late October 2023. The Net Effect The Global Cement and Concrete Association (GCCA) 2050 Cement and Concrete Industry Roadmap for Net Zero Concrete is a commitment by the major producers around the world to accelerate the decarboniza-tion of concrete and cement. Major producers from across the globe agreed to an ambitious intermediate goal of enr.com/SpecialAd Lower life-cycle cost and greater resistance to salt intrusion are just two of the benefits found in UHPC. 30 | November 13/20, 2023 PHOTO: DELAWARE RIVER AND BAY AUTHORITY ELAWARE RIVER AND BAY AUTHORITY
ENR Sections Concrete Today IV: Page-30
