Trade Journals for the Concrete Industry

Precast concrete structures are recognised among the structural typologies which may mostly suffer from the progressive collapse phenomenon, also due to past bad experiences related to accidents occurred in buildings constructed employing old precast technologies neglecting the basic robustness criteria and characterised by poorly detailed and/or executed joints and connections. The passive structural robustness criteria for multi-storey precast buildings as framed by the main design codes worldwide are based on the formation of a system of vertical and horizontal ties which enter into function after the loss of one or multiple main structural elements occurring as a consequence of an unexpected event. Extensive damage and large deformation of the concrete elements, although preventing chain failure, is accepted due to the limited probability of occurrence of the load event.