Case Study: Ultra High Performance Concrete with Steel Fibers for the Route 624 Bridge in Virginia

摘要

Ultra high performance concrete (UHPC) containing steel fibers was used in five beams of the bridge on Route 624 over Cat Point Creek in Virginia. A test beam was also fabricated and tested to failure. The beam had strands but no shear stirrups. Test beam results indicated satisfactory load-carrying capacity. Preparation of the beams involved a longer mixing time and a two-stage steam curing to ensure optimum concrete properties. Testing of specimens at the hardened state showed that UHPC has high strength and high durability attributable to a very low water-cementitious materials ratio, low permeability, a high resistance to cycles of freezing and thawing, and tight cracks.