Concrete hinge

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concrete hinge Kalliauer 2016 Masterarbeit Fig8.5 onlyHingeFront2D.svg
concrete hinge
concrete hinge with front side notches Kalliauer 2016 Masterarbeit Fig8.6.png
concrete hinge with front side notches

Concrete hinges are hinges produced out of concrete, with no or almost no steel in the hinge neck, which allows a rotation without a relevant bending moment. [1] This high rotations [2] [3] are resulting from controlled tensile cracks as well as creep. [4] [3] [1] Concrete hinges are mostly used in bridge engineering [1] as monolithic, simple, economic alternative to steel hinges, which would need regular maintenance. Concrete hinges are also used in tunnel engineering. [1] [3] A concrete hinge consist of the hinge neck, which has a reduced cross section and of the hinge heads, which have a strong reinforcement. [3] [1] [5]

Contents

History and guidelines

Freyssinet [6] [7] invented the concrete hinges. [1] [3] Leonhardt introduced guidelines in the 1960s which are still used till the 2010s. [1] [3] Janßen introduced the application of concrete hinges in tunnel engineering. [8] [3] Gladwell developed another guideline for narrowing cross sections, which predicts a stiffer behaviour than the Leonhardt/Janßen-model [3] Marx and Schacht translated Leonhardts guidelines for the first time in the nowadays used semipropablistic safteyconcept. Schlappal, [3] Kalliauer [1] and coworkers introduced for the first time both limit caces (service-limit-states (SLS) and ultimate-limite-states (ULS)). Kaufmann, Markić und Bimschas did further studies on concrete hinges. [9]

Stresses, rotational capacity, bearing capacity

normal stesses in loading direction Kalliauer et al 2018 Acta Mechanica Fig3b.svg
normal stesses in loading direction
normal stresses in thickness direction Kalliauer et al 2018 Acta Mechanica Fig3c.svg
normal stresses in thickness direction
normal stresses in side direction Kalliauer et al 2018 Acta Mechanica Fig3d.svg
normal stresses in side direction

Due to triaxial compression, strength in the neck region is much higher than for uniaxial compression, [4] because lateral expansion is restricted. [1] Eurocode 2 suggests for typical dimensions a compressive strength equal to about twice of the unixalial compressive strength. [1] Also the concrete hinge neck has no, or almost no reinforcement, [1] but the concrete hinge heads need a dense reinforcement cache, because of the tensile splitting. [10] [9]

Literature

Related Research Articles

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References

  1. 1 2 3 4 5 6 7 8 9 10 11 Johannes Kalliauer; Thomas Schlappal; Markus Vill; Herbert Mang; Bernhard Pichler (2018-02-01). "Bearing capacity of concrete hinges subjected to eccentric compression: multiscale structural analysis of experiments". Acta Mechanica. 229 (2): 849–866. doi: 10.1007/s00707-017-2004-3 . ISSN   1619-6937.
  2. Schlappal et al. did experiments till above 50mrad (Fig11).
  3. 1 2 3 4 5 6 7 8 9 Thomas Schlappal; Michael Schweigler; Susanne Gmainer; Martin Peyerl; Bernhard Pichler (2017), "Creep and cracking of concrete hinges: insight from centric and eccentric compression experiments", Materials and Structures, Springer, vol. 50, no. 6, p. 244, doi:10.1617/s11527-017-1112-9, PMC   5700241 , PMID   29213209
  4. 1 2 Johannes Kalliauer; Thomas Schlappal; Herbert A. Mang; Bernhard Pichler (2018). "Parameter identification as the basis for Finite Element simulations of Ultimate Limit States of concrete hinges". In Günther Meschke; Bernhard Pichler; Jan G. Rots (eds.). Computational Modelling of Concrete Structures: Proceedings of the Conference on Computational Modelling of Concrete and Concrete Structures (EURO-C 2018), February 26 – March 1, 2018, Bad Hofgastein, Austria. CRC Press. p. 689. Retrieved 2018-03-06.
  5. Fritz Leonhardt; Horst Reimann (1965), Betongelenke: Versuchsbericht; Vorschläge zur Bemessung und konstruktiven Ausbildung. Kritische Spannungszustände des Betons bei mehrachsiger, ruhender Kurzzeitbelastung (in German), Ernst
  6. Eugène Freyssinet (1923), "Le pont de Candelier (The bridge of Candelier)", Ann Ponts Chaussées (in French), vol. 1, pp. 165f
  7. Eugène Freyssinet (1954), "Naissance du béton précontraint et vues d'avenir.", Travaux, Juni (in French), pp. 463–474
  8. Pieter Janßen (1983), Tragverhalten von Tunnelausbauten mit Gelenktübbings (in German), Dissertation, Technische Universität Braunschweig
  9. 1 2 Walter Kaufmann; Tomislav Markić; Martin Bimschas (February 2017), Betongelenke - Stand der Technik und Entwicklungspotential (PDF) (in German), Institut für Baustatik und Konstruktion, ETH Zürich
  10. Johannes Kalliauer (2016-04-29), Insight into the structural behavior of concrete hinges by means of Finite Element simulations, Wien: TU Wien - Vienna University of Technology