PSI - Issue 78

Enes Krasniqi et al. / Procedia Structural Integrity 78 (2026) 261–268

263

 TR02a: Specimen with short embedment length and mechanical nut anchorage.  TR02b: Specimen with medium embedment length, also incorporating a mechanical nut.

All configurations are embedded in precast concrete blocks and centrally reinforced with threaded steel bars of M24 diameter. The concrete elements were detailed with stirrup confinement to investigate interaction effects between radial confinement and anchorage efficiency. The embedded bars extended into the specimens to simulate in-situ boundary conditions, with pullout loading applied axially. The experimental layout was selected to apply pure axial tensile behaviour of the anchorage systems, as represented in Figure 1. The inclusion of mechanical nuts aimed to reduce the required embedment length while still activating concrete bearing stress and mobilising ductile bar behaviour.

TR01- specimen, section A-A

Cross section B-B

TR02- specimen, section A-A

Cross section B-B

Figure 1. Geometry representation of TR01 and TR02 specimens

3. Finite Element modelling of the specimens This study employed advanced nonlinear finite element analysis to investigate the behaviour of mechanical anchorage systems in precast concrete elements under tensile loading. All numerical models were developed using the GiD preprocessor coupled with the ATENA Science software suite. The modelling strategy included explicit definition of cracking, crushing, bond-slip phenomena, and localised damage. Three finite element models were set to replicate the experimental configurations tested in this research, as highlighted above. These included model TR01b, representing a medium embedment length without a mechanical nut, serving as the reference specimen (Figure 2(a)); model TR02a, featuring a short embedment length combined with a mechanical nut (Figure 2(b)); model TR02b, comprising a medium embedment length with mechanical nut anchorage (Figure 2(c)).