The behaviour of precast systems depends on the performance of the specific connections between the precast elements. In European precast design practice, the most common type of connection between beams and columns is a dowel connection. Such connections are subject to the following types of potential failure mechanism: (a) local failure characterized by the simultaneous yielding of the dowel and crushing of the surrounding concrete, and (b) global failure, characterized by spalling of the concrete between the dowel and the edge of the column or the beam. In this paper both types of failure of dowel connections are studied, although somewhat more attention is paid to the less investigated global failure. The local failure mechanism has been relatively well investigated, and the results have been presented in several studies. Thus only some minor changes are proposed in connection with the prediction of the related strength. On the other hand, the majority of existing procedures for the estimation of global strength are over-conservative since they neglect the influence of stirrups, or else only take them into account implicitly. None of these methods explicitly take into account the fact that the global failure of the dowel connection is changed by the presence of stirrups from brittle to ductile. In the paper, a new procedure for the estimation of resistance against global failure is proposed. Taking into account an appropriate strut and tie model of the connections, the influence of stirrups on this resistance as well as on the type of the failure is taken into account explicitly. Comparisons that were performed between the analytically calculated strength and the experimental results obtained have clearly shown that both of the proposed procedures for the estimation of resistance against local and global failure agree very well with the experimental results.

No abstract

No abstract