Provided is a method for manufacturing segments for a tower, in particular of a wind turbine, and a prestressed segment for a tower. Provided is tower ring for a tower, a tower of the wind turbine, and a wind turbine. In addition, a prestressing device is provided. The method for manufacturing segments for a tower, in particular of a wind turbine, comprises: arranging at least one prestressing element in a mold, wherein the prestressing element comprises or consists of fiber-reinforced plastic; tensioning the prestressing element; embedding the prestressing element in a concrete mass; hardening of the concrete mass into a longitudinal segment, preferably in the form of a complete longitudinal segment of a tower; removing the hardened longitudinal segment from the mold.

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 is related to a mold device for molding a waffle slab, wherein a plurality of connecting structures made of steel bars protrude from the sides of the waffle slab, the mold device comprising: a plurality of steel molds provided at both sides of each of the plurality of connecting structures and surrounding the waffle slab, each of the plurality of steel molds having a top surface, which has a hole therein; a plurality of auxiliary devices respectively disposed at the sides of the waffle slab and having through holes corresponding to holes in the plurality of steel molds; and a plurality of fasteners; wherein the plurality of fasteners respectively pass through the through holes of the plurality of auxiliary devices and are fixed into the holes of the plurality of steel molds so that each of the plurality of auxiliary device transversely connects the top surfaces of the plurality of steel molds.

The method according to the invention for producing a prestressed concrete workpiece is characterized in that the prestress is created by a heat treatment, wherein the concrete and the reinforcement therefor are selected in such a way that, when cooling the concrete workpiece from an elevated temperature, the heat expansion coefficient of the concrete is less than that of the reinforcement, and in that, during cooling, the concrete and the reinforcement adhere sufficiently strongly to one another if, during cooling, the concrete is hydrated at least to such an extent in order to be able to expand the reinforcement on account of the different heat expansion coefficients, and in that the concrete, together with the reinforcement, is brought to the elevated temperature in such a way that and is hydrated during cooling at least to such an extent that it is prestressed by the reinforcement after cooling.

In a method for producing a plurality of concrete cast elements of prestressed concrete, in particular for producing of railway sleepers, in a long bed which is a multiple of the length of a concrete cast element, in which separating elements are installed in the long bed to define the length of each of the concrete cast elements to be casted, a first and a second separating element for defining the length of a concrete cast element together with a tensioning device with tensioning elements for tensioning the concrete cast element between the two separating elements are mounted in the long bed, whereupon the concrete cast element is cast between the two separating elements and is at least partially hardened in the long bed.

Prestressed carbon fibers of at least one textile structure comprising carbon fibers are embedded in a concrete matrix. At least one textile structure comprising carbon fiber bundles is laid in a mold at a distance from one another, into two accommodation elements which are arranged at two diametrical end faces of the mold. Hollow spaces within the accommodation element are filled with a rapid-curing viscous composition having a mineral basis or rapid-curing polymer. After curing the composition or of the polymer, tensile forces act on the accommodation element(s) in the longitudinal direction of the carbon fiber bundles with a tensioning device. During the tensile force the interior of the mold is subsequently filled completely with viscous concrete. After curing of the concrete, the tensile forces on the prestressed carbon fiber bundles are largely transferred to the cured concrete and the concrete component can then be removed from the mold.

Provided is a method for manufacturing segments for a tower, in particular of a wind turbine, and a prestressed segment for a tower. Provided is tower ring for a tower, a tower of the wind turbine, and a wind turbine. In addition, a prestressing device is provided. The method for manufacturing segments for a tower, in particular of a wind turbine, comprises: arranging at least one prestressing element in a mold, wherein the prestressing element comprises or consists of fiber-reinforced plastic; tensioning the prestressing element; embedding the prestressing element in a concrete mass; hardening of the concrete mass into a longitudinal segment, preferably in the form of a complete longitudinal segment of a tower; removing the hardened longitudinal segment from the mold.

There is proposed a reinforced concrete structure comprising a reinforcement assembly embedded therein, the reinforcement assembly including first and second lengths of chain, wherein the first and second lengths of chain being pretensionable prior to forming the concrete structure. The reinforcement assembly includes pretensionable member/s and/or resiliently deformable member/s intermediate of at least one tetherable end of the lengths of chain and a mounting block or link member.

The present disclosure is related to a mold device for molding a waffle slab, wherein a plurality of connecting structures made of steel bars protrude from the sides of the waffle slab, the mold device comprising: a plurality of steel molds provided at both sides of each of the plurality of connecting structures and surrounding the waffle slab, each of the plurality of steel molds having a top surface, which has a hole therein; a plurality of auxiliary devices respectively disposed at the sides of the waffle slab and having through holes corresponding to holes in the plurality of steel molds; and a plurality of fasteners; wherein the plurality of fasteners respectively pass through the through holes of the plurality of auxiliary devices and are fixed into the holes of the plurality of steel molds so that each of the plurality of auxiliary device transversely connects the top surfaces of the plurality of steel molds.

The method according to the invention for producing a prestressed concrete workpiece is characterized in that the prestress is created by a heat treatment, wherein the concrete and the reinforcement therefor are selected in such a way that, when cooling the concrete workpiece from an elevated temperature, the heat expansion coefficient of the concrete is less than that of the reinforcement, and in that, during cooling, the concrete and the reinforcement adhere sufficiently strongly to one another if, during cooling, the concrete is hydrated at least to such an extent in order to be able to expand the reinforcement on account of the different heat expansion coefficients, and in that the concrete, together with the reinforcement, is brought to the elevated temperature in such a way that and is hydrated during cooling at least to such an extent that it is prestressed by the reinforcement after cooling.