Biegeverstärkung mit Carbonbeton

Abstract

Bestehende Stahlbetonkonstruktionen können mit einer Vielzahl an Systemen instand gesetzt bzw. verstärkt werden, wobei zu den gebräuchlichsten Methoden eine Verstärkung mit Spritzbeton oder mit Lamellen aus faserverstärkten Kunstoffen (FVK) gehört. In den vergangenen Jahren hat sich mit Textilbeton eine weitere Möglichkeit entwickelt, bei der es sich um eine dünne, leistungsfähige Verstärkungsschicht aus einem Feinbeton handelt, welche mit einem textilen Gelege bewehrt ist. Die Dicke einer solchen Schicht beträgt üblicherweise zwischen 10 und 20 mm, kann letztlich jedoch je nach geforderten Randbedingungen davon abweichen. Als Material für diese Gelege kommen verschiedene technische Endlosfasern z. B. aus alkaliresistentem Glas (AR-Glas), Carbon oder Basalt infrage. Carbonbeton (CRC-carbon reinforced concrete) enthält Carbonbewehrung in Form von Gelegen oder Stäben. Allgemeine Informationen zum Baustoff Carbonbeton und dessen Anwendungsfeldern können bspw. [1-4] entnommen werden.

RC members with a flexural‐strengthening layer of CFRP textile‐reinforced concrete under monotonic and cyclic long‐term loading

“…The experimental and theoretical investigations were done in a collaborative research effort of the Technical Universities of Dresden and Darmstadt (Germany). The production process of the RC members as well as the experimental investigations under short-term loading are well reported in Müller et al 4 The test setup, cross-sectional dimensions and the reinforcement layout are shown in Figure 1.…”

“…In Figure 13B, the ultimate loads of the reference tests and the residual strength tests are shown. The load‐bearing capacities of the unreinforced members reported in Müller et al, 4 yield to a mean value of approximately F max,RU,m = 19.2 kN ( M max,RU,m = 7.2 kNm) compared with a value of F max,RS,m = 92.2 kN ( M max,RS,m = 34.6 kNm) for the strengthened members. The latter is in good agreement with the calculation in Section 3.1 and is approximately 7% higher.…”

“…This fact becomes particularly clear in the following comparison of the residual load‐bearing capacities. Müller et al, 4 have investigated the structural behavior of the unstrengthened and strengthened members under short‐term loading. Figure 13A shows the force–deflection curves under short‐term loading of the unstrengthened and strengthened members reported in Müller et al, 4 as well as the curves from the residual strength tests of the members after monotonic and cyclic loading presented in Section 4.…”

“…Müller et al, 4 have investigated the structural behavior of the unstrengthened and strengthened members under short‐term loading. Figure 13A shows the force–deflection curves under short‐term loading of the unstrengthened and strengthened members reported in Müller et al, 4 as well as the curves from the residual strength tests of the members after monotonic and cyclic loading presented in Section 4. It has to be noted that the preloaded specimens have an initial deflection due to irreversible cracking and creep effects by the monotonic and cyclic long‐term loading.…”

“…The steel reinforcement is in accordance with DIN 488 11 . The material properties of the longitudinal steel reinforcement were determined by Müller et al, 4 on 10 samples and can be summarized as follows:…”