Experimental Investigation of the Shear Resistance of Concrete Hinges Under a Biaxial Load

Abstract

Concrete hinges can withstand extremely high loads and rotations, while requiring only minimal maintenance. Their use is widespread, mainly in bridge construction, but they also find applications in the prefabrication of tunnel segments. With the right design and implementation, they can meet the highest requirements for the durability and resistance of a structure. However, the existing models and design procedures are relatively outdated. The models are based solely on empirical assumptions, whereas the shear resistance of the joint itself plays only a marginal role. The following paper aims to compare existing design models against experimental results in order to find the most suitable design approach that reliably captures the performance of a hinge under a shear load. An experimental program was developed in which 9 samples of concrete hinges were tested for different levels of axial loads and degrees of reinforcement. The results of the experiments were then compared with the selected design models, and a numerical nonlinear analysis was conducted.

Modeling and design of concrete hinges under general loading

“…Note that for Specimen CH3 and V2 shear failure could not be induced, hence the actual model errors are lower for these specimens. Test data by Havlíček et al, 28 Base, 17 Marki c et al, 16 and Reintjes. 48 plotted against the specimen names (Figure 12a) and the normalized average axial stress across the throat (Figure 12).…”

“…Similar to the shear strength of concrete structures without shear reinforcement and the shear transfer across interfaces, the shear resistance of concrete hinges a somewhat controversial topic. 28 Due to the hinge geometry, shear failures of concrete hinges are constrained to the throat region, hence the established shear design approaches for slabs and beams cannot be applied. On the other hand, the shear transfer across the throat differs from common interface shear cases due to the high axial compressive forces and hinge rotations.…”

“…Recently, 28,41 it has been proposed to analyze the shear resistance of concrete hinges with approaches for concrete-to-concrete interfaces, considering all relevant contributions to the interface shear transfer, that is, adhesive bond, mechanical interlocking, friction, and dowel action of the reinforcement. As an example, consider the pertinent clause of Eurocode 2 42 (adapted to the nomenclature used in this paper):…”

“…15,19 However, a moderate reinforcement, that is, A s /(b 1 d 1 ) < 5%, 24 in the form of vertical bars crossing the hinge throat may be useful, primarily as a precaution against brittle shear failure or to cover accidental design situations (e.g., impact loading or earthquake). 16,17,[25][26][27][28] This throat reinforcement should cross the throat along the hinge rotation axis (y = 0) in order to minimize the impediment of the hinge rotation; the bars can be slightly inclined in the y-direction (crosswise) to improve shear transfer in the transverse direction (V y ). Some authors recommended not to use ribbed reinforcing bars through the throat to avoid the risk of localized (tensile) yielding in the throat, which would interfere with the closure of the throat in compression.…”

Large‐scale experiments on concrete hinges under general loading

“…This is mainly due to a considerable degree of uncertainty in their design caused by the scarcity of experimental data 3 and the resulting lack of adequately substantiated design rules. Most experimental campaigns were conducted more than half a century ago, 4–15 and only a few more recent experimental investigations are available 16–21 . Moreover, these past experimental investigations clearly focused on the behavior under the standard load case, that is, axial compressive load and hinge rotations.…”