Advances in the science of concrete materials have led to the development of a new class of cementitious composites called ultra-high performance concrete (UHPC). The links above will direct you to pages detailing UHPC projects, bridges with UHPC components, articles that focus on UHPC research, and the main contact at Turner-Fairbank Highway Research Center (TFHRC) for UHPC.
The mechanical and durability properties of UHPC make it an ideal candidate for use in developing new solutions to pressing concerns about highway infrastructure deterioration, repair, and replacement. Since 2000, when UHPC became commercially available in the United States, a series of research projects has demonstrated the capabilities of the material. A handful of State departments of transportation have deployed UHPC components within their infrastructure, and many more are actively considering the use of UHPC.
UHPC is a cementitious composite material composed of an optimized gradation of granular constituents, a water-to-cementitious materials ratio less than 0.25, and a high percentage of discontinuous internal fiber reinforcement. The mechanical properties of UHPC include compressive strength greater than 21.7 kilopounds per square inch (ksi) (150 Megapascals (MPa)) and sustained postcracking tensile strength greater than 0.72 ksi (5 MPa). Ultra-high performance concrete has a discontinuous pore structure that reduces liquid ingress, significantly enhancing durability compared to conventional and high-performance concretes.
UHPC is being considered for use in a wide variety of highway infrastructure applications. The high compressive and tensile strengths allow for the redesign and optimization of structural elements. Concurrently, the enhanced durability properties facilitate a lengthening of design life and allow for potential use as thin overlays, claddings, or shells. In the United States, UHPC has been used in prestressed concrete girder simple-span bridges, precast concrete deck panels, and field-cast connections between prefabricated bridge components. Figure 1 shows the first UHPC highway bridge constructed in the United States.
Figure 1. This Wapello County, Iowa, structure was the first UHPC bridge constructed in the United States. The bridge includes three UHPC prestressed I-girders spanning a creek in rural Iowa.