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.

A method and an apparatus for casting prefabricated prestressed concrete products with a substantially horizontal slipform casting process, in which method reinforcement strands are stressed in a bundle on a casting bed before the slipform casting is started, wherein the expected behavior of at least one measurable variable affecting the strand stressing process during the strand stressing process is predetermined, and the behavior of the at least one measurable variable is measured and compared to its predetermined expected behavior during the strand stressing process.

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.

A system and method for applying tension to a reinforcement member is provided. The system includes a gripping device, a tension device, and a tension application sub-system. The gripping device includes first and second attachments. Each attachment retains a respective end of the reinforcement member with sufficient friction force based on a predetermined tension to be applied to the reinforcement member. The tension device includes first and second tension tubes configured to removably receive and hold the first and second attachments, respectively. The tension application sub-system has first and second tension application apparatuses and first and second coupling devices. The first and second coupling devices couple the first and second tension tubes to the first and second tension application apparatuses, respectively. At least one of the first and second tension application apparatuses creates and controllably adjusts a tension load within the reinforcement member.

A system and method for allowing components to attach to a pre-cast pre-stressed concrete structure is provided. The system includes a first attachment part and a second attachment part. The first attachment part has a first body. The first body has a first concrete structure facing side and a first plurality of attachment members extending from the concrete structure facing side. The second attachment part has a second body. The second body has a second concrete structure facing side and a second plurality of attachment members extending from the concrete structure facing side. The first and second attachment parts are spaced apart forming a compressible junction therebetween. The pre-cast, pre-stressed concrete structure is formed from uncured cement, at least of a portion of the first and second attachment members being embedded in the pre-cast, pre-stressed concrete structure.

System and method allows a component to attach to a pre-cast, pre-stressed concrete structure. The system includes a first attachment part, a pre-cast, pre-stressed concrete member and first and second reinforcing members. A first body of a first attachment part has a first concrete structure facing side and a first plurality of attachment members. The pre-cast, pre-stressed concrete member is formed from uncured cement. At least a portion of the attachment members are embedded within the pre-cast, pre-stressed concrete member. The first reinforcing member is placed under a first tension load and the second reinforcing member is placed under a second tension load. The pre-cast, pre-stressed concrete member is formed from uncured cement poured about at least a portion of the first and second reinforcing members while the first and second reinforcing members are under stress.

A reinforcing bar, and a method of producing a reinforcing bar, are provided. The reinforcing bar includes a plurality of strands and a deformity pattern. Each strand includes a plurality of carbon fibers. The strands having been impregnated with a resin and twisted forming a unified structure. The deformity pattern being formed within the unified structure by twisting the strands a predetermined number of times per linear foot of the unified structure and allowing the resin-impregnated unified structure to cure.

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 continuous fiber reinforcing material tension apparatus includes a pressing body that presses a sleeve to a side of a fixed structure and contains a hollow portion, in which a wedge body is allowed to reciprocate along a continuous fiber reinforcing material, a cylindrical bracket located in an opposite side of the sleeve from the pressing body and having an inner wall surface on which a projection is formed, a columnar rotary jig that is allowed to reciprocate inside the bracket, that engages with an end face of the wedge body, that has a spiral key groove that engages with a key, and that applies rotative force around an axis of the continuous fiber reinforcing material, and a piston that presses an end face of the rotary jig to a side of the fixed structure.

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.