Abstract: Various implementations include a structure. The structure includes a precast concrete column cap having a first side surface, a second side surface opposite and spaced apart from the first side surface. The structure includes a bottom surface, and a top surface opposite and spaced apart from the bottom surface. The precast concrete column cap includes at least one post-tensioning duct extending between the first side surface and the second side surface. At least one of the first side surface or the second side surface defines a shear key interface. The structure includes at least one precast concrete column having a top surface. The bottom surface of the precast concrete column cap is disposed on the top surface of the at least one column.

Abstract: Various implementations include methods and apparatuses for constructing a concrete structure. In one implementation, a structure includes a pre-cast concrete column section and a pre-cast concrete beam section. The column section includes an embedded first assembly with a threaded rod, and the beam section includes an embedded second assembly defining a channel for receiving the threaded rod. Grout is fed through a joint between the column and beam sections into the second assembly to couple the threaded rod with the second assembly. The grout is urged through the joint and the second assembly by gravity and by applying vacuum suction to a grout port defined by the second assembly. The grout port extends between the channel of the second assembly and an external face of the beam section.

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: 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: Various implementations include methods and apparatuses for constructing a concrete structure. In one implementation, a structure includes a pre-cast concrete column section and a pre-cast concrete beam section. The column section includes an embedded first assembly with a threaded rod, and the beam section includes an embedded second assembly defining a channel for receiving the threaded rod. Grout is fed through a joint between the column and beam sections into the second assembly to couple the threaded rod with the second assembly. The grout is urged through the joint and the second assembly by gravity and by applying vacuum suction to a grout port defined by the second assembly. The grout port extends between the channel of the second assembly and an external face of the beam section.

Abstract: Various implementations include a corrugated concrete floor system that includes a plurality of elongated pre-cast concrete floor support units disposed in a horizontal arrangement relative to each other for each floor of a building. The concrete floor support units are disposed between floors of a multi-story building. The units define a plurality of supply air plenums and return air plenums that are arranged alternately in the sandwich space between each floor. The supply air plenums are in fluid communication with the building level above them, and the return air plenums are in fluid communication with the building level below them. By having the supply-air plenum and the return-air plenum share the volume occupied by concrete floor support units, the height of the sandwich space is reduced.

Abstract: Various implementations include methods and apparatuses for constructing a concrete structure. In one implementation, a structure includes a pre-cast concrete column section and a pre-cast concrete beam section. The column section includes an embedded first assembly with a threaded rod, and the beam section includes an embedded second assembly defining a channel for receiving the threaded rod. Grout is fed through a joint between the column and beam sections into the second assembly to couple the threaded rod with the second assembly. The grout is urged through the joint and the second assembly by gravity and by applying vacuum suction to a grout port defined by the second assembly. The grout port extends between the channel of the second assembly and an external face of the beam section.

Abstract: Various implementations include methods and apparatuses for constructing a concrete structure. In one implementation, a structure includes a pre-cast concrete column section and a pre-cast concrete beam section. The column section includes an embedded first assembly with a threaded rod, and the beam section includes an embedded second assembly defining a channel for receiving the threaded rod. Grout is fed through a joint between the column and beam sections into the second assembly to couple the threaded rod with the second assembly. The grout is urged through the joint and the second assembly by gravity and by applying vacuum suction to a grout port defined by the second assembly. The grout port extends between the channel of the second assembly and an external face of the beam section.

Abstract: Various implementations include methods and apparatuses for constructing a concrete structure. In one implementation, a structure includes a pre-cast concrete column section and a pre-cast concrete beam section. The column section includes an embedded first assembly with a threaded rod, and the beam section includes an embedded second assembly defining a channel for receiving the threaded rod. Grout is fed through a joint between the column and beam sections into the second assembly to couple the threaded rod with the second assembly. The grout is urged through the joint and the second assembly by gravity and by applying vacuum suction to a grout port defined by the second assembly. The grout port extends between the channel of the second assembly and an external face of the beam section.

Abstract: Various implementations comprise methods and apparatuses for constructing a concrete structure. An apparatus according to one implementation includes a structure comprising a pre-cast concrete component that includes at least one post-tensioning duct, a post-tensioning tendon extending through the post-tensioning duct, and a poured in place concrete surface disposed above and coupled to the pre-cast concrete component.

Abstract: Various implementations include methods and apparatuses for connecting concrete structural elements, such as pre-cast concrete structural elements. In one implementation, an apparatus includes a first concrete structural element into which a first duct is pre-cast, a second concrete structural element into which a second duct is pre-cast, and a duct coupler that couples the first duct in fluid communication with the second duct and prevents adhesive from flowing into the first or second duct when the first and second concrete structural elements are coupled together. In another implementation, a method of forming a concrete structural element includes disposing at least a portion of a duct within a form for receiving poured concrete, disposing a duct holder through an opening in the form and coupling the duct holder with the duct to hold the duct in position within the form during pouring, and removing the duct holder after the concrete hardens.

Abstract: Various implementations comprise methods and apparatuses for constructing a concrete structure. An apparatus according to one implementation includes a structure comprising a pre-cast concrete component that includes at least one post-tensioning duct, a post-tensioning tendon extending through the post-tensioning duct, and a poured in place concrete surface disposed above and coupled to the pre-cast concrete component.

Abstract: Various implementations include methods and apparatuses for connecting concrete structural elements, such as pre-cast concrete structural elements. In one implementation, an apparatus includes a first concrete structural element into which a first duct is pre-cast, a second concrete structural element into which a second duct is pre-cast, and a duct coupler that couples the first duct in fluid communication with the second duct and prevents adhesive from flowing into the first or second duct when the first and second concrete structural elements are coupled together. In another implementation, a method of forming a concrete structural element includes disposing at least a portion of a duct within a form for receiving poured concrete, disposing a duct holder through an opening in the form and coupling the duct holder with the duct to hold the duct in position within the form during pouring, and removing the duct holder after the concrete hardens.

Abstract: The present invention broadly comprises a tower and a method and apparatus for constructing a tower, where one embodiment of apparatus includes a foundation, a plurality of lower staves located on the foundation, and a plurality of upper staves located above the lower staves, the upper staves having a poured in place concrete or grout joint between each adjacent upper stave.

Abstract: Various implementations include methods and apparatuses for constructing a concrete structure. In one implementation, a structure includes a pre-cast concrete column section and a pre-cast concrete beam section. The column section includes an embedded first assembly with a threaded rod, and the beam section includes an embedded second assembly defining a channel for receiving the threaded rod. Grout is fed through a joint between the column and beam sections into the second assembly to couple the threaded rod with the second assembly. The grout is urged through the joint and the second assembly by gravity and by applying vacuum suction to a grout port defined by the second assembly. The grout port extends between the channel of the second assembly and an external face of the beam section.

Abstract: The present invention broadly comprises a method and apparatus for constructing a concrete tower. In one embodiment, a tower construction apparatus includes an alignment jig and a pre-cast concrete element located on the alignment jig.

Abstract: An assembly includes a first block including a first end; and a second block assembled with the first block at a same height as the first block, the second block including a second end facing the first end of the first block. The first block and the second block are connected to the assembly such that there is no structural connection between the second end of the second block facing the first end of the first block.

Abstract: The present invention broadly comprises a method and apparatus for constructing a concrete lower. In one embodiment, a tower construction apparatus includes an alignment jig and a pre-cast concrete element located on the alignment jig.

Abstract: The present invention broadly comprises a tower and a method and apparatus for constructing a tower, where one embodiment of apparatus includes a foundation, a plurality of lower staves located on the foundation, and a plurality of upper staves located above the lower staves, the upper staves having a poured in place concrete or grout joint between each adjacent upper stave.