A combined concrete cone breakout—pull-out model for cast-in-place fasteners

Cast-in-place fasteners are widely used in civil engineering to connect steel or other elements to reinforced concrete. Despite the inherent importance of such components in structural design, the introduction of dedicated mechanical models for their verifications is quite recent. Nonetheless, the existing models are still characterized by many simplified assumptions, which cover aspects not fully understood and shared within the scientific community. In the present paper, a refined mechanical model is proposed to overcome one of those hypotheses in the evaluation of the concrete-related failure modes in tension, particularly concrete cone breakout and pull-out failure. The model is conceived to cover a broad range of fastening solutions with a single formula. To this end, evidence from available experimental and numerical investigations is recalled. Data from the literature are critically analyzed in order to calibrate the parameters of the new model.