ABSTRACT
Fastening systems have become essential elements in civil engineering constructions as the field of application of modern fastening technique is expanding. In recent years, the construction industry saw a shift towards rehabilitation and modular construction to address the growing demand for faster construction on one side and the change in usage and sustainability on the other side. Consequently, efficient design and utilization require a thorough understanding of all involved materials and their changes throughout their lifetime. Considering the potential damage and consequences due to anchorage failure, it is obvious that such products must undergo rigorous approval tests. Practice has shown that for the same concrete class and anchor type load capacities can vary, especially when the results are compared between different laboratories in a worldwide scope. There are several different possible reasons that can cause such differences, and for some of these limited restrictions are given (e.g., only the minimum concrete age is specified). This contribution presents an experimental campaign investigating two potential influence factors on the concrete cone capacity: (i) age and curing, and (ii) the aggregate effect. The investigation comprises full material characterization for each aggregate and concrete, and structural pull-out tests on mechanical anchors performed at two ages. Finally, the experimentally obtained data is used to check the current design codes in an attempt to evaluate the predictive quality of the investigated models and their sensitivity with regard to the discussed influence factors.
