Abstract: Ultra-High-Performance Concrete (UHPC), owing to its superior mechanical and durability properties, presents a unique opportunity for innovative use in unbonded post-tensioned floor systems. In unbonded post-tensioned (PT) slabs and beams, the use of cast-in-place steel confined UHPC Bond Anchors (UBA) can be used to anchor steel prestressing strands for better durability, increased strand ductility, cost-effectiveness, and ease of installation. A conical, steel confining device is used as part of the UBA. The device resists hoop tension and eliminates splitting cracks in the UHPC during prestress transfer. It also helps to reduce the anchorage length. High average bond stress helps reduce the UBA length, and consequently, the material consumption. The bond stress at the strand-UHPC interface can be increased by intentionally roughening or indenting the strand.

Abstract: Ultra-High-Performance Concrete (UHPC), owing to its superior mechanical and durability properties, presents a unique opportunity for innovative use in unbonded post-tensioned floor systems. In unbonded post-tensioned (PT) slabs and beams, the use of cast-in-place steel confined UHPC Bond Anchors (UBA) can be used to anchor steel prestressing strands for better durability, increased strand ductility, cost-effectiveness, and ease of installation. A conical, steel confining device is used as part of the UBA. The device resists hoop tension and eliminates splitting cracks in the UHPC during prestress transfer. It also helps to reduce the anchorage length. High average bond stress helps reduce the UBA length, and consequently, the material consumption. The bond stress at the strand-UHPC interface can be increased by intentionally roughening or indenting the strand.

Abstract: A wind turbine tower system is provided which includes a wind turbine tower with a height of at least 80 meters, said wind turbine tower comprised of ultra-high performance concrete and a wind turbine mounted on the wind turbine tower. The wind turbine tower system may include a vertically extending lattice structure formed of a plurality of modular components, wherein each of said plurality of modular components being pre-stressed. The tower may also be formed using UHPC shells.

Abstract: A wind turbine tower system includes a wind turbine tower with a height of at least 100 meters, said wind turbine tower. The wind turbine tower includes a plurality of hexagonal-shaped or other shapes of vertical columns comprised of a concrete composition and a plurality of panels, each of the plurality of panels extending between adjacent vertical columns. The plurality of vertical columns and the plurality of panels are arranged to provide a hexagonal cross-section for the wind turbine tower.

Abstract: A wind turbine tower system includes a wind turbine tower with a height of at least 100 meters, said wind turbine tower. The wind turbine tower includes a plurality of hexagonal-shaped or other shapes of vertical columns comprised of a concrete composition and a plurality of panels, each of the plurality of panels extending between adjacent vertical columns. The plurality of vertical columns and the plurality of panels are arranged to provide a hexagonal cross-section for the wind turbine tower.