A self-stressing shape memory alloy (SMA)/fiber reinforced polymer (FRP) composite patch is disclosed that can be used to repair cracked steel members or other civil infrastructures. Prestressed carbon FRP (CFRP) patches have emerged as a promising alternative to traditional methods of repair. However, prestressing these patches typically requires heavy and complex fixtures, which is impractical in many applications. This disclosure describes a new approach in which the prestressing force is applied by restraining the shape memory effect of nickel titanium niobium alloy (NiTiNb) SMA wires. The wires are subsequently embedded in an FRP overlay patch. This method overcomes the practical challenges associated with conventional prestressing.

The present disclosure relates to a device and a method for reinforcing a round section wood beam by the combination of a prestressed Fiber Reinforce Plastic (FRP) sheet and a high strength steel wire rope. The device includes an FRP sheet adhered to a bottom surface of a log beam in the length direction. A middle supporting piece is mounted in the middle of the log beam. An end part reinforcing anchoring piece is mounted at each of two ends of the log beam. FRP hoops are adhered to the log beam and are located between the middle supporting piece and each of the end part reinforcing anchoring pieces at intervals in the length direction. High strength steel wire ropes with both ends connected to the corresponding end part reinforcing anchoring pieces are respectively arranged on the two sides of the middle supporting piece.

This method is suitable for the strengthening of concrete or timber structures (1, 4) by applying prestressed Carbon FRP or Glass FRP lamella (8). Firstly, at least one groove (22) is cut into the concrete or timber structure (1, 4) along the direction in which the concrete or timber structure (1, 4) is to be strengthened. The grooves (22) are filled with epoxy resin (9) and a layer of epoxy resin (9) is put onto the entire section to be equipped with the CRFP or GFRP lamella (8). The lamella (8) will be prestressed and anchored at both ends. U-shaped brackets (24) are then being put over the two end sections of the CFRP or GFRP lamella (8) by inserting and submerging its both U-legs (27) into holes (26) filled with resin as well. These holding brackets (24) will then tightly press onto the CFRP or GFRP lamella (8) to prevent cracking or fracture of the concrete or timber and bending away of the extremities of the CFRP or GFRP lamella.

The present disclosure relates to a device and a method for reinforcing a round section wood beam by the combination of a prestressed Fiber Reinforce Plastic (FRP) sheet and a high strength steel wire rope. The device includes an FRP sheet adhered to a bottom surface of a log beam in the length direction. A middle supporting piece is mounted in the middle of the log beam. An end part reinforcing anchoring piece is mounted at each of two ends of the log beam. FRP hoops are adhered to the log beam and are located between the middle supporting piece and each of the end part reinforcing anchoring pieces at intervals in the length direction. High strength steel wire ropes with both ends connected to the corresponding end part reinforcing anchoring pieces are respectively arranged on the two sides of the middle supporting piece.

This method is suitable for the strengthening of concrete or timber structures by applying prestressed Carbon FRP or Glass FRP lamella. At least one groove is cut into the concrete or timber structure along the direction in which the concrete or timber structure is to be strengthened. The grooves are filled with epoxy resin and a layer of epoxy resin is put onto the entire section to be equipped with the CRFP or GFRP lamella. The lamella is prestressed and anchored at both ends. U-shaped brackets are then being put over the two end sections of the CFRP or GFRP lamella by inserting and submerging its both U-legs into holes filled with resin as well. These holding brackets are then tightly pressed onto the CFRP or GFRP lamella to prevent cracking or fracture of the concrete or timber and bending away of the extremities of the CFRP or GFRP lamella.

Self-stressing engineered composites that include a matrix containing self-stressing reinforcement that is activated by an activator that causes, in situ, the self-stressing reinforcement to transfer at least some of its pre-stress into portions of the matrix adjacent the self-stressing reinforcement. In some embodiments, the activator can be of a self-activating, an internal activating, and/or an external activating type. In some embodiments, the self-stressing reinforcement includes an active component that holds and transfers pre-stress to a matrix and a releasing component that causes the active component to transfer its pre-stress to the matrix. In some embodiments, the self-stressing reinforcement is initially unstressed and becomes stressed upon activation. Various engineered composites, self-stressing reinforcement, and applications of self-stressing engineered composites are disclosed.

An automatic tensioning system for strengthening a beam, a slab and a column by a pre-stressed FRP plate comprises a tensioning end anchor (1), a fixed end anchor (10), and a tensioning bracket (3) connected to the tensioning end anchor (1). A centre-hole jack (16) is provided in the middle of the tensioning bracket (3), a threaded rod (8) passes through the tensioning bracket (3) and is then connected to the centre-hole jack (16), and an upper toothed nut (13) and a lower toothed nut (19) respectively driven by a driving mechanism are provided on two sides of the tensioning bracket (3) on the threaded rod (8). A binary clip-type fixture (4) is further comprised, an upper surface thereof is provided with a cylinder (6), and a sleeve (7) nested outside the cylinder (6) is connected to the threaded rod (8).

A self-stressing shape memory alloy (SMA)/fiber reinforced polymer (FRP) composite patch is disclosed that can be used to repair cracked steel members or other civil infrastructures. Prestressed carbon FRP (CFRP) patches have emerged as a promising alternative to traditional methods of repair. However, prestressing these patches typically requires heavy and complex fixtures, which is impractical in many applications. This disclosure describes a new approach in which the prestressing force is applied by restraining the shape memory effect of nickel titanium niobium alloy (NiTiNb) SMA wires. The wires are subsequently embedded in an FRP overlay patch. This method overcomes the practical challenges associated with conventional prestressing.

A self-stressing shape memory alloy (SMA)/fiber reinforced polymer (FRP) composite patch is disclosed that can be used to repair cracked steel members or other civil infrastructures. Prestressed carbon FRP (CFRP) patches have emerged as a promising alternative to traditional methods of repair. However, prestressing these patches typically requires heavy and complex fixtures, which is impractical in many applications. This disclosure describes a new approach in which the prestressing force is applied by restraining the shape memory effect of nickel titanium niobium alloy (NiTiNb) SMA wires. The wires are subsequently embedded in an FRP overlay patch. This method overcomes the practical challenges associated with conventional prestressing.

An automatic tensioning system for strengthening a beam, a slab and a column by a pre-stressed FRP plate comprises a tensioning end anchor (1), a fixed end anchor (10), and a tensioning bracket (3) connected to the tensioning end anchor (1). A centre-hole jack (16) is provided in the middle of the tensioning bracket (3), a threaded rod (8) passes through the tensioning bracket (3) and is then connected to the centre-hole jack (16), and an upper toothed nut (13) and a lower toothed nut (19) respectively driven by a driving mechanism are provided on two sides of the tensioning bracket (3) on the threaded rod (8). A binary clip-type fixture (4) is further comprised, an upper surface thereof is provided with a cylinder (6), and a sleeve (7) nested outside the cylinder (6) is connected to the threaded rod (8).