Zusammenwirken von Beton und Stahlprofil bei kammerbetonierten Verbundträgern

Composite structures consisting of structural steel and concrete maximize the advantages of the two components provided that there is sufficient shear connection. When high strength materials are applied, the positive effect becomes even more apparent. Today, using high strength materials and partially concrete encased steel profiles is becoming more and more popular and requested in modern construction. Not only the fire resistance of the composite section but also the bending stiffness as well as the load bearing capacity can be increased significantly. Generally, the composite action is achieved by headed studs welded onto the steel web. Adhesion as well as friction forces between the steel profile and the concrete encasement contribute to the bond effect, however, due to creep and shrinkage of the concrete these effects can be diminished. Thus, the scope of the dissertation is to calculate the friction forces taking into account the time-dependent material properties. The present publication reports on the interaction between high strength concrete encasement and the high strength steel profile in composite bridges and industrial structures. Numerous experimental and theoretical investigations have been performed regarding the load carrying mechanisms and their characteristics. In order to determine the effectiveness of shear connectors in uncracked as well as cracked concrete a new shear test has been developed. The influence of shrinkage of the concrete encasement has been identified for distinct concrete ages by means of extensive measurement techniques. In beam tests the load carrying behavior and the rotation capacity of partially concrete encased composite beams has been investigated under positive and negative bending moments. In order to apply the yield-line theory it has to be verified that the yield strain of the steel profile is achieved before the concrete section fails due to the exceeding concrete strains. With increasing concrete strength the strain at failure decreases in contrast to the high yield strain which is required for the high strength steel to plasticize. The load carrying behavior of the concrete encasement is characterized by a three-dimensional stress condition where the bearable compressive strains are increased significantly. By varying the degree of shear connection of the concrete encasement the influence of a partial shear connection has also been determined. By means of non-linear finite element simulation not only the global load carrying capacity has been verified but also the internal mechanisms which occur in the composite cross section have been visualized. The results of the finite element simulation show different positive effects on the load bearing behavior of composite beams. In the bending moment region the encased concrete as well as the longitudinal reinforcement are activated primarily by friction bond between the concrete and the steel flanges. Friction bond is mainly governed by the flexural curvature of the beam and in positive moment areas by the lateral contraction of the structural steel in case of tension stress. In the region of negative moments the concrete is confined by the steel profile and the stirrup reinforcement. Thus, the sustainable concrete stresses are increased. If sufficient shear connection is provided, the concrete encasement is able to increase the capacity of the section against buckling. Based on own investigations and tests described in literature design recommendations for partially encased composite beams are developed. A novel plastic design method for composite beams with concrete encasement is presented for both, full and partial shear connection. The effects of the rotation capacity which is required to achieve a plastic strain distribution and the bond between the concrete encasement and the steel profile are considered as well as the influence of creep and shrinkage of the concrete.

Grantor dc:publisher

Eigenverl.

Year dc:date

2006

Author dc:creator

• Goralski, Claus

Contributors dc:contributor

• Hegger, Josef

• info:eu-repo/classification/ddc/620
• Coulombsches Reibungsgesetz
• Kontakt <Reibung>
• Nichtlineare Finite-Elemente-Methode
• Tragverhalten
• Verbundbrücke
• Zerstörende Werkstoffprüfung
• Verbundträger
• Hochfester Stahl
• Hochfester Beton
• Ingenieurwissenschaften
• Kammerbeton
• Verbundmittel
• Rotationsverhalten
• Abscherversuch
• structural steel
• concrete encasement
• shear connection
• finite element analysis
• experimental studies

Statement dc:rights

• info:eu-repo/semantics/openAccess

Language dc:language

ger

Identifier

https://publications.rwth-aachen.de/search?p=id:%22RWTH-CONV-114845%22

OAI record oai:identifier

https://publications.rwth-aachen.de/oai2d?verb=GetRecord&metadataPrefix=oai_dc&identifier=oai%3Apublications.rwth-aachen.de%3A52637