Abstract: A method to strengthen or repair concrete and other structures comprises securing a plate having a shape memory alloy (SMA) wire embedded therein to a localized region of a structure. The SMA wire has a deformed shape configured for self-anchorage within the plate. The SMA wire is heated at or above an austenite transformation temperature, and the SMA wire resists shape recovery and remains self-anchored within the plate. Accordingly, a compressive force is generated within the SMA wire and transferred to the plate. At an interface between the plate and the localized region of the structure, the compressive force is transmitted from the plate to the structure, thereby providing localized prestressing of the structure.

Abstract: A concrete product comprising an adaptive prestressing system includes a concrete body and a composite wire embedded within the concrete body at a predetermined location. The composite wire comprises anchored end portions, each of which comprises a bonded wire segment constrained within the concrete body to resist axial motion, and an activable central portion between the end portions. The activable central portion comprises a shape memory alloy (SMA) wire segment and is axially movable within the concrete body. When heated at or above an austenite transformation temperature, the SMA wire segment contracts and the activable central portion exerts a tensile force on the end portions, thereby applying a compressive prestress within the concrete body at the predetermined location.

Abstract: A method to strengthen or repair concrete and other structures comprises securing a plate having a shape memory alloy (SMA) wire embedded therein to a localized region of a structure. The SMA wire has a deformed shape configured for self-anchorage within the plate. The SMA wire is heated at or above an austenite transformation temperature, and the SMA wire resists shape recovery and remains self-anchored within the plate. Accordingly, a compressive force is generated within the SMA wire and transferred to the plate. At an interface between the plate and the localized region of the structure, the compressive force is transmitted from the plate to the structure, thereby providing localized prestressing of the structure.