Engineering:Concrete hinge
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]
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
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
- Fritz Leonhardt: Vorlesungen über Massivbau - Teil 2 Sonderfälle der Bemessung im Stahlbetonbau. [Concrete hinges: test report, recommendations for structural design. Critical stress states of concrete under multiaxial static short-term loading Springer-Verlag, Berlin 1986, ISBN:3-540-16746-3, S. 123–132. (in German)
- VPI: Der Prüfingenieur. Ausgabe April 2010, S. 15–26, (bvpi.de PDF; 2,3 MB). (in German)
References
- ↑ 1.00 1.01 1.02 1.03 1.04 1.05 1.06 1.07 1.08 1.09 1.10 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. https://link.springer.com/content/pdf/10.1007%2Fs00707-017-2004-3.pdf:PDF.
- ↑ Schlappal et al. did experiments till above 50mrad (Fig11).
- ↑ 3.0 3.1 3.2 3.3 3.4 3.5 3.6 3.7 3.8 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) 50 (6): 244, doi:10.1617/s11527-017-1112-9, PMID 29213209
- ↑ 4.0 4.1 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". CRC Press. p. 689. https://www.crcpress.com/Computational-Modelling-of-Concrete-Structures-Proceedings-of-the-Conference/Meschke-Pichler-Rots/p/book/9781138741171. Retrieved 2018-03-06.
- ↑ Fritz Leonhardt; Horst Reimann (1965) (in German), Betongelenke: Versuchsbericht; Vorschläge zur Bemessung und konstruktiven Ausbildung. Kritische Spannungszustände des Betons bei mehrachsiger, ruhender Kurzzeitbelastung, Ernst
- ↑ Eugène Freyssinet (1923), "Le pont de Candelier (The bridge of Candelier)" (in French), Ann Ponts Chaussées 1: 165f
- ↑ Eugène Freyssinet (1954), "Naissance du béton précontraint et vues d'avenir." (in French), Travaux, Juni: 463–474
- ↑ Pieter Janßen (1983) (in German), Tragverhalten von Tunnelausbauten mit Gelenktübbings, Dissertation, Technische Universität Braunschweig
- ↑ 9.0 9.1 Walter Kaufmann; Tomislav Markić; Martin Bimschas (February 2017) (in German), Betongelenke - Stand der Technik und Entwicklungspotential, Institut für Baustatik und Konstruktion, ETH Zürich, https://www.research-collection.ethz.ch/bitstream/handle/20.500.11850/257076/201501%2bSchlussbericht%2bKaufmann%2bBetongelenke%20korr.pdf
- ↑ 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
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