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Experimental investigations of shallow mechanical and bonded anchors in textile reinforce concrete
Published in Airong Chen, Xin Ruan, Dan M. Frangopol, Life-Cycle Civil Engineering: Innovation, Theory and Practice, 2021
M. Hoepfner, P. Spyridis, M. Bessling, J. Orlowsky
As it is seen from the study, influenced of the fiber reinforcement the load-bearing capacity of the anchors is mainly evident for shear loads. The failure modes exhibited in axial include concrete cone failure, occasionally with propagation of splitting cracks. In shear, the tests failed under pry out and concrete edge breakout failure.
Numerical simulation of anchoring systems in concrete
Published in Günther Meschke, René de Borst, Herbert Mang, Nenad Bićanić, Computational Modelling of Concrete Structures, 2020
B. Winkler, Y.-J. Li, A. Eckstein
For the HSL anchor, as a friction type anchor, the tensile load is transferred from anchor to base material due to the friction created by expanded segments. In the first step the anchoring system is loaded by applying the respective setting moment. Due to pre-stressing the cone and the segments as well as the segments and the concrete get in contact and activate the required friction behavior due to expansion forces. Afterwards the anchor is loaded by a pull-out force in vertical direction resulting in a typical concrete cone failure as shown in Fig. 3.
Size Effect in Concrete Structures
Published in Alberto Carpinteri, Applications of Fracture Mechanics to Reinforced Concrete, 2018
Rolf Eligehausen, Joško Ožbolt
Example (3)—The concrete cone failure load of headed anchors embedded in a large concrete block is studied. The geometry of the specimen is shown in Fig. 2(c). It is correlated with the embedment depth d. The smallest embedment depth is d = 50 mm. The distance between support and anchor is 3d, so that an unrestricted formation of the failure cone is possible. The axisymmetric finite element mesh, shown in Fig. 13 (deformed shape), is constant in all analysed cases, i.e. the elements are scaled in proportion to d. Contact between anchor and concrete in the direction of loading exists under the head of the anchor only. To account for the restraining effect of the embedded anchor, the displacements of the concrete surface along the anchor in the vicinity of the head are fixed in the direction perpendicular to the load direction. Except at supports, all other nodes at the concrete surface are supposed to be free. Microplane model parameters are taken so that the calculated tension strength is approximately ft = 3 MPa and the uniaxial compression strength is fc = 40 MPa. The characteristic length of the nonlocal continuum is taken as lc = 12 mm. Pulling out of the anchor is performed by prescribing displacements at the bottom of the head.
Methodology for development of AS 5216 using international harmonisation of construction products standard
Published in Australian Journal of Structural Engineering, 2022
J. Lee, A. Amirsardari, L. Pham, E. F. Gad
This section demonstrates the adaptation process for a single anchor for a fundamental failure mode in concrete under tension loading. Concrete cone failure as shown in Figure 1 is the most common mode of failure and it is also the most desirable failure mode compared to other modes of failure in concrete. The most widely adopted theoretical prediction model for concrete cone failure in many international standards including EN 1992–4 and AS 5216 was developed by Fuchs, Eligehausen, and Breen (1995) as follows: whereNRk,c= strength of single anchor to concrete conefailurek = empirical constant linking the strength of the anchor to other parameters derived from testingf’c= characteristic compressive strength of concretehef= effective embedment depth of fastener
Pullout Tests on Post-installed Bonded Anchors in Ultra-high Performance Fiber Reinforced Concrete
Published in Structural Engineering International, 2019
Few results on the behavior of post-installed bonded anchors in steel fiber reinforced or (ultra) high strength concrete are available.11–15 Among these, in Ref. [11], monotonic tension tests were carried out on 12 and 16 mm diameter adhesive anchors at embedment depths ranging from 40 to 160 mm. Normal strength and high strength concrete were used with, respectively, a compressive strength of 30 or 50 MPa. In some mixtures, steel fibers of 60 mm long and 0.8 mm in diameter were used with a fiber content of 0.8% and 1% by volume. With the addition of steel fibers the damage of concrete was significantly reduced. In case of a concrete cone failure, the concrete cones, in steel fiber reinforced concretes, were of three or more pieces rather than one complete one. The use of steel fibers in concrete did not affect the pullout capacity of the anchors, but the failure type of some anchors shifted from concrete cone to pullout mode or combined pullout and cone mode. Moreover, the displacement at maximum load was generally higher in steel fiber reinforced concrete. For deeper embedment depths, the influence of steel fibers on the displacement at the ultimate load was greatly reduced. In Ref. [12], tests were carried out in steel fiber reinforced concrete with headed cast-in-place anchor. Concrete strength ranged from 27.4–58 MPa, four steel volume fractions of steel fibers ranging from 0.4% to 1.6%, three anchor diameters (8, 10 and 12 mm), and four embedment depth from 25 to 62.5 mm were used. The majority of the specimens failed by concrete cone failure. The addition of steel fibers to concrete increased the concrete cone breakout capacity of the anchors. In fibrous concrete, the concrete cone angle was increasing and the failure cones were smaller than in concrete specimens without fibers.
Design of cast-in headed and hooked fasteners
Published in Australian Journal of Structural Engineering, 2018
D. Heath, J. Lee, B. King, E. F. Gad, R. Eligehausen
The concrete cone failure mode is characterised by the formation of a cone-shaped fracture surface in the concrete as shown in Figure 8(a). The full tensile capacity of the concrete is utilised. The projected cone area is idealised into a square as shown in Figure 8(b).