Abstract: A sleeve lock locks concrete reinforcing steel bars within rigid support structure retainers for stabilizing the reinforcing bars in place, while allowing the bars to spin freely within sleeves or holes within the retainers. The sleeve locks are stable couplings holding concrete reinforcing bars in position while allowing the bars to spin within the couplings. This reduces the need for tightening locks or fasteners at elevated heights of vertically positioned concrete reinforcing steel bars.

Abstract: An erection system for one or more elongated elements, such as structural columns, pre-fabricated reinforcing cages or tower-like structures includes one or more longitudinal lifting bars running parallel with the elongated element's longitudinal direction. The lifting bars are installed within or onto the elongated element through apertures in the element's upper and lower support pieces. A rigging system supports the upper portion of the lifting bar. The lifting bar's lower portion includes external threading to receive an internally threaded load bearing nut. The load bearing nut supports the elongated element's weight onto the lifting bar's lower portion. The upper and lower support pieces stabilize the elongated element with lateral restraint. Removing the load bearing nut and raising the lifting bar up through the support piece's apertures extracts the lifting bar from the elongated element.

Abstract: A pre-fabricated reinforcement cage is constructed of at least two cage frames spaced apart from each other. The cage frames include preferably axially extending steel plates and axially extending sleeves preferably having an internal threading pattern that is complimentary to the external threading pattern of a plurality of longitudinal reinforcing bars. The cage frames are optionally also provided with lifting bar guide collars to receive a lifting apparatus comprised of one or more lifting bars. The cage frame plates, sleeves and lifting bar guide collars are fastened together. The longitudinal reinforcing bars, having continuous, external thread-like deformations along their length are installed into the internally threaded sleeves or into threads of locking nuts holding the bars within optional smooth sleeves during the fabrication.

Abstract: According to one embodiment, the energy dissipation of a structural element is increased by inserting one or more resisting elements into the structural element at any time during or after construction of the structural element. The continuous resisting elements are rigidly attached to the structural at one end and connected to the structural element by and through a damping material over at least a portion of its length. When a dynamic force is applied to the structural elements, such as may result from wind or earthquakes, there will be a strain in the structure, in a direction parallel with the longitudinal direction of the resisting elements. In this way, the forces and deformations within the structure will result in a relative motion between the structural element and resisting element, a substantial portion of which is ultimately transmitted by and through the damping material layer.

Abstract: According to one embodiment, the energy dissipation of a structural element is increased by inserting one or more resisting elements into the structural element at any time during or after construction of the structural element. The continuous resisting elements are rigidly attached to the structural at one end and connected to the structural element by and through a damping material over at least a portion of its length. When a dynamic force is applied to the structural elements, such as may result from wind or earthquakes, there will be a strain in the structure, in a direction parallel with the longitudinal direction of the resisting elements. In this way, the forces and deformations within the structure will result in a relative motion between the structural element and resisting element, a substantial portion of which is ultimately transmitted by and through the damping material layer.