PSI - Issue 66

Lucie Malíková et al. / Procedia Structural Integrity 66 (2024) 142–147 Author name / Structural Integrity Procedia 00 (2025) 000–000

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concrete free edges. Concrete cone breakout is typical by a cone-shaped fracture in concrete material in the vicinity of the anchor. In general, concrete cone breakout is characterized as a brittle failure. This behavior proves the load displacement curves that drops sharply after peak load because of fast and unstable propagation of concrete cracks. Numerous numerical and experimental studies have been done on single cast-in-place anchors subjected to tensile loading and it has been found out that the concrete cone circumferential cracking occurs at approximately 30 % of the ultimate load, see e.g. Eligenhausen et al. (2006). Furthermore, it was observed that the propagation of the concrete cone crack corresponds to the anchor embedment depth: particularly, the length of the concrete cone crack at the specific loading decreases with increasing anchor embedment depth. In general, it is important to investigate how various parameters affects behavior of anchor/concrete system and its failure and/or to suggest suitable prediction models. Several results can be found for instance in Ottosen (1981), Stone and Carino (1983), Krenchel and Shah (1985), Eligehausen and Sawade (1989), Fuchs et al. (1995) or Elfgren et al. (2001) etc. In this paper, the tangential stress distribution is investigated at certain radial distances from the anchor’s corner and the angle, where the maximum occurs, is searched. The dependence of this angle on both the radial distance and depth of the anchor’s embedment is investigated and discussed. This complex parametrical study is performed via finite element simulations on a suggested model of a steel cast-in anchor embedded in a cylindrical concrete substrate. Comparison with the experimentally observed crack propagation angles is discussed.

Nomenclature L air

length of the part of the steel anchor in the air

length of the part of the steel anchor embedded in the concrete substrate

L em L tot

total length of the concrete substrate smaller radius of the steel anchor larger radius of the steel anchor radius of the concrete substrate

R 1 R 2 R 3

R C critical radial distance from the anchor’s corner where the tangential stress was investigated t height of the anchor’s base  max angle where the maximum of the tangential stress occurs   tangential stress 2. Numerical and material model The scheme of the cast-in anchor embedded in a concrete substrate can be seen in Fig. 1, where one slice of the cylindrical concrete specimen with an embedded steel anchor considered for numerical simulations can be seen.

Fig. 1. A scheme of one slice of the cylindrical concrete specimen with an embedded steel anchor; the circle, where the stress distribution was investigated, is indicated.