Cracking and crushing in prestressed concrete beams

The cohesive/overlapping crack model represents an effective tool in the study of failure transition phenomena occurring in plain or reinforced concrete structures. In the present paper, this non-linear fracture mechanics model is applied to study the global structural behavior of prestressed concrete beams casted by means of pre-tensioning technique or, more generally, having a straight steel strand layout. In this context, a thorough analysis of scale effects is presented to investigate local mechanical instabilities such as snap-back and snap-through phenomena due to concrete cracking or crushing, highlighting the crucial role of the ductile-to-brittle transition in the design of prestressed concrete structural elements.