Bemessung texilbetonverstärkter Stahlbetonbauteile unter Biegebeanspruchung

Abstract

In diesem Beitrag werden auf der herkömmlichen Stahlbetonbemessung basierende Berechnungs‐ und Bemessungsmodelle zur Bestimmung der Tragfähigkeit biegebeanspruchter, textilbetonverstärkter Stahlbetonbauteile vorgestellt. Mit dem aufgeführten Berechnungsansatz können sowohl die verschiedenen Versagensarten Textilzug‐, Stahlzug‐ und Betondruckversagen als auch eingebrachte Spannungszustände vor der Verstärkungsmaßnahme berücksichtigt werden. Neben einem iterativen Berechnungsablauf werden zwei vereinfachte Formelapparate zur überschläglichen Dimensionierung der für die Verstärkung erforderlichen Textilbetonschicht vorgestellt. Der Artikel stellt des Weiteren Tabellen und Diagramme für eine einfache und praxisgerechte Bemessung bereit. Die Anwendung der Berechnungs‐ und Bemessungsverfahren wird abschließend anhand von Beispielrechnungen demonstriert.Design of RC members strengthened with textile reinforced concrete under flexural bendingThis paper presents analysis methods and design models based on the conventional reinforced concrete design procedure, that are used to determine the nominal capacity of flexural bending of steel reinforced concrete members strengthened with textile reinforcement. The shown computational algorithm allows considering different failure modes such as textile and steel tensile failure, concrete compressive collapse and introduced stress states, which act before the strengthening measure. In addition to an iterative calculation process, two simplified formulas are given to easily calculate the necessary area of reinforcement of strengthened elements under bending. Furthermore, the article provides tables and charts for a simple and practical design calculation. The application of analysis and design methods is demonstrated conclusively on the basis of example calculations.

Flexural Strengthening of RC Structures with TRC—Experimental Observations, Design Approach and Application

“…In Figure 3, different possible stress-strain relationships for carbon reinforcement are shown. The variant 1 (Figure 3a, used in Reference [25,46]) derived from material behavior observed in tension tests in former years where the investigated textile grids made of AR glass or carbon have shown a less stiff stress-strain behavior at lower load levels, e.g., due to undulation of yarns after manufacturing [45][46][47]. The meanwhile available carbon reinforcements show a nearly linear material behavior which led to a modification of the material model, variant 2 in Figure 3b (compare e.g., [47]) and variant 3 in Figure 3c, respectively.…”

“…A first model was presented by Bösche in Reference [43] in 2007. Meanwhile, it was further developed [42,[44][45][46][47] and modified due to new knowledge and research findings for the later used materials. Furthermore, a similar design proposal is presented in Carloni et al [23].…”

Lightweight ceiling system made of carbon reinforced concrete

“…To specify the required cross section of the textile grid, known design models can be used, for example. [3][4][5] These models are based on the model used for RC structures with steel reinforcement, where the required reinforcement is iteratively determined by finding a balance between the internal and external forces or moments from normal forces and bending moments. The computer-aided results were verified by simplified calculation by hand.…”

“…The compressive strength f cm , the flexural strength f ctm,fl , and the Young's modulus E cm of the fine-grained concrete was determined by testing of 40 × 40 × 160 mm 3 prisms, according to the technical approval. 8 The grain size of this fine-grained concrete is thereby less than 1 mm.…”

Carbonstäbe im Bauwesen

“…Weiterhin dürfen in Deutschland Biegebauteile aus Stahlbeton mittels einer allgemeinen bauaufsichtlichen Zulassung mit Textilbeton verstärkt werden . Carbonbeton ist zudem für die Erhöhung der Querkraft‐, Torsions‐ und Längskrafttragfähigkeit von bestehenden Stahlbetontragwerken geeignet oder für die Herstellung neuer Bauteile, z. B.…”