Re-fer Ag

Empa

Eidgenoessische Materialpruefungs- Und Forschungsanstalt Empa

Eidgenossische Materialprufungs-und Forschungsanstalt Empa

Christian Leinenbach

Masoud Motavalli

Christoph Czaderski

Benedikt Weber

Rolf Bronnimann

Rolf Brönnimann

Rolf Broennimann

Wookjin Lee

Wookijn Lee

Julien Michels

Moslem Shahverdi

The method includes a tension element, for example in the form of flat steel, that is placed on the structure or structural part and can be guided around a corner. The flat steel can also wrap as a band around the structure, in which the two ends of the flat steel are either connected to one another or are separately connected to the structure by the end anchors or intersect to produce a clamping connection. The flat steel contracts as a result of a subsequent active and controlled input of heat using a heating element and generates a permanent tensile stress and, correspondingly, a permanent prestress on the structure. The structure, as equipped, has at least one tension element as a shape memory alloy which extends along the outer side of the structure and is connected by one or more end anchors.

Method for producing prestressed structures and structural parts by means of SMA tension elements, and structure and structural part equipped therewith

The invention relates to a method according to which a profile consisting of a shape-memory alloy is placed into concrete, or a concrete to be reinforced is roughened on the outside, then profiles () consisting of a shape-memory alloy are fastened to the roughened outside () of the structure () and a cementitious matrix is applied to the roughened outside () to cover the profiles (). After the cementitious matrix has set, said profiles () produce a contraction force and thus a tension as a result of the input of heat. The mortar covering layer () thereby acts as a reinforcement layer owing to the interlocking of the mortar covering layer () with the roughened outside () of the structure (). The profiles () run in an outer mortar as a reinforcement layer () of the outside of a structure along the outside of the structure inside the mortar or reinforcement layer (). A structure can also be prepared for a prestress in the equipped mortar or reinforcement layer by the input of heat, in that electrical cables () are routed from the end regions thereof to the outside of the mortar or reinforcement layer () or the end regions of the electrical cables () are accessible by removing inserts ().

Method for building prestressed concrete structures by means of profiles consisting of a shape-memory alloy, and structure produced using said method

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Fehraltdorf, Switzerland

Christian Leinenbach