Ehsani, M.R., “Reconstruction Methods for Structural Elements” U.S. Patent No. 8,650,831, Feb 18, 2014. This patent is primarily for repairing a column or pile by confining the column and the grout. A spacer sheet is positioned around the pile at a distance and FRP fabric is wrapped continuously around the pile on top of those spacer sheets. The annular space between the spacer sheets and the pile or column is filled with resin or grout. This provides an impervious jacket around the corroded pile to keep oxygen and moisture away and thus significantly reduce the corrosion rate. The number of layers of FRP fabric and the type of fibers can be designed to achieve the required confining pressure for each project. The procedure shown in this video for repair of large structures such as pier walls is in accordance with this patent.
Ehsani, M.R., “Repair and Strengthening of Piles and Pipes with FRP Laminates,” U.S. Patent No. 9,376,782, June 28, 2016. This patent is repair and strengthening of piles and columns using PileMedic® laminates. The laminates are wrapped around the pile or column to create an annular space. As an option, reinforcing elements can be positioned within that annular space. The annular space is filled with grout or resin. The number of layers of PileMedic® and the type of fiber (glass or carbon) can be designed to provide any confinement pressure required for the project. This system also provides an impervious jacket around the pile which would prevent moisture and oxygen ingress, thus bringing the corrosion rate to near halt. This technique has been tested by multiple government agencies including the US Army Corps of Engineers and it is the only system used by the US Military worldwide and many of our clients in the US and internationally. The wide range of application of this patent also include strengthening cell phone towers, timber utility poles, steel structures in substations, etc.
Ehsani, M.R., “Buckling Reinforcement for Structural Elements,” U.S. Patent No. 9,719,255, Aug 1, 2017. This patent offers a very economical solution for converting ordinary braces into a Buckling Restrained Brace (BRB). The brace is first coated with a bond-inhibiting agent. PileMedic® laminates are wrapped around the brace at a distance to create an annular space. The annular space is filled with concrete or grout. The technique is ideal for retrofitting ordinary braces in existing structures (as a part of seismic retrofit of structures) into stronger and more ductile Buckling Restrained Brace (BRB). This paper presented at the 11th US National earthquake Engineering Conference provides more information and test results on this system.
Ehsani, M.R., “Reinforcement and Repair of Structural Columns,” U.S. Patent No. 9,890,546, Feb 13, 2018. This patent covers the repair and strengthening of columns and piles by providing reinforcing elements that are anchored into the slab, floor or beams above and below the column. The reinforcing elements are encased in an external jacket made with PileMedic® and the annular space between the column or pile and PileMedic® is filled with concrete, grout or resin. The anchoring of the reinforcing elements into the floors ensures a moment-resisting connection for transfer of axial loads as well as bending (flexural) stresses from the repaired column to the structural elements above and below the column or pile. Our solution for repair of cell phone towers that includes anchoring of steel rebars into the foundation is one such application that is based on this patent.
Ehsani, M.R., “Spacers for Repair of Columns and Piles,” U.S. Patent No. 10,808,412, Oct. 20, 2020. This patent covers the various spacers that we manufacture as part of our pile and column repair system. Several spacers can be mounted on a zip tie that is fastened around the pile. These spacers allow easy installation of reinforcing bars at predetermined locations with fixed clear cover spacing. Instead of requiring a team of divers to handle the reinforcing cage, a single diver can attach the spacers and snap the reinforcing elements into the spacers. One design is used for sealing the bottom of the annular space, others for corners of columns, another design for H-piles, and so on. One of the many projects that has utilized these spacers is shown in this video for repair of timber piles.
Ehsani, M.R., “Structural Reinforcement Partial Shell,” US Patent No. 10,968,631, Apr 6, 2021. This patent has numerous applications in repair of concrete beams, seawalls, decks, pipes, etc. A premanufactured semirigid FRP panel is fixed to the surface of the structure at a distance away from the face of the structure, creating a small annular space between the structure and the FRP. The annular space is filled with epoxy or other types of grouts. Our Sheet Pile Repair (SPiRe®) system is based on this patent. That product has been used successfully on projects repairing seawalls for the U.S. Coastguard, port facilities and industrial clients. The US Navy has used this solution on several projects as well.