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: Various implementations include a system for coupling a post to a foundation. The system includes a rod having a first rod end and a second rod end. The first rod end is spaced apart from a top surface of the foundation, and the second rod end is coupled to the foundation. The post has at least one side wall at least partially defining an inner cavity and an inner tube disposed within the inner cavity and coupled to the at least one side wall. The inner tube has a first tube end and a second tube end that is closer than the first tube end to a bottom end of the post. A portion of the rod is disposable within the inner tube such that the first rod end is axially spaced apart from the first tube end. The first rod end is couplable to the first tube end.

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 a system for coupling a post to a foundation. The system includes a rod having a first rod end and a second rod end. The first rod end is spaced apart from a top surface of the foundation, and the second rod end is coupled to the foundation. The post has at least one side wall at least partially defining an inner cavity and an inner tube disposed within the inner cavity and coupled to the at least one side wall. The inner tube has a first tube end and a second tube end that is closer than the first tube end to a bottom end of the post. A portion of the rod is disposable within the inner tube such that the first rod end is axially spaced apart from the first tube end. The first rod end is couplable to the first tube end.

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 method and apparatus for constructing a tower, where the apparatus may include a structure including a foundation including a plurality of hydraulic cylinders; a truss tower located on the foundation and configured to support a tower built on the foundation; and a controller configured to control extension and retraction of the hydraulic cylinders.

Abstract: A method and apparatus for constructing a tower, where the apparatus may include a structure including a foundation including a plurality of hydraulic cylinders; a truss tower located on the foundation and configured to support a tower built on the foundation; and a controller configured to control extension and retraction of the hydraulic cylinders.

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 method and apparatus for constructing a tower, where the apparatus may include a structure including a foundation including a plurality of hydraulic cylinders; a truss tower located on the foundation and configured to support a tower built on the foundation; and a controller configured to control extension and retraction of the hydraulic cylinders.

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: A pipe rack and a method for making a pipe rack where the pipe rack may include at least one foundation, two legs, and a horizontal support. The two legs are supported by the at least one foundation. Each of the two legs includes at least one aperture. The horizontal support has two ends. The first end is located in an aperture in a first leg of the two legs and a second end of the horizontal support is located in an aperture in a second leg of the two legs. A rod forms a joint between the foundation and one of the two legs. The rod is located in the aperture in the upper surface of the foundation and in an aperture in a lower surface in the one of the two legs.

Abstract: Various implementations comprise a method and apparatus for constructing a concrete structure in stages. In various implementations, an apparatus includes a base, a support column located on the base, and a movable scaffolding rotatably coupled to a top of the support column. According to various other implementations, a method for assembling a tower stage includes: (1) providing a base platform; (2) coupling a pole to the base platform; (3) disposing two or more staves around the pole; (4) coupling the staves together to form the tower stage; and (5) removing the tower stage from the platform.

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.