Abstract: A voided floor panel is provided. The voided floor panel includes a pre-cast dome, strands, reinforcing bars, and a slab. The pre-cast dome includes a flange portion, stem portions, and joint portions. The strands are pre-tensioned. The reinforcing bars are inserted through rebar block-outs of the pre-cast dome. The joint portions, the strands, and the reinforcing bars are cast within the slab. The strands improve a resistance of the slab to flexure. The joint portions improve a vertical shear resistance between the slab and the pre-cast dome. The joint portions may include corrugated dovetails for further improving a horizontal shear resistance between the slab and the pre-cast dome.

Abstract: An ultra high performance concrete (UHPC) voided slab panel may include a top slab including a top skin and a bottom slab including a bottom skin. The top slab and the bottom slab may be joined at a joint filled with a joint material and positioned a select height within the UHPC voided slab panel. The top slab and the bottom slab may be joined via a connector assembly. The panel may include least two ribs defining at least one void accessible via at least one opening through an exterior surface of the UHPC voided slab panel. The UHPC voided slab panel may be fabricated from UHPC and a plurality of embedded prestressing strands, and may be configured to meet select strength requirements that are greater than select strength requirements for conventional precast concrete without reinforcing bars being embedded within the UHPC voided slab panel.

Abstract: Flange-to-flange connectors and construction methods using such connectors are disclosed. The connector may include a first and second anchored plates secured to a first and second sets of anchoring bars. The connector may also include a first and second alignment plates configured to mate with the first and second anchored plates. The connector may further include at least one shim configured to be positioned between the first and second anchored plates. A bolt may be configured to secure the first and second alignment plates with the first and second anchored plates, respectively, and when the bolt is tightened, the bolt pulls the first and second alignment plates and the first and second anchored plates together to form a rigid connection, which may eliminate the need to form and cure concrete at job sites, allowing the time, cost, and construction complexity to be reduced significantly compared to conventional connection systems.

Abstract: Methods and systems for constructing wind towers are disclosed. A wind tower may be constructed by vertically stacking and securing a plurality of modular units. Each modular unit of the plurality of modular units may include three generally hexagonal columns and three concrete panels coupled to the three generally hexagonal columns. The three concrete panels and the three generally hexagonal columns may jointly form a generally equilateral triangular prism.