Retrofitting of a precast industrial building

Four years ago, a precast industrial building collapsed due to the failure of a pre-stressed beam. A wide experimental investigation was carried out on site to judge the remaining beam conditions; a full-size TT beam, produced according to the same design specifications, was tested up to the maximum load that caused the disaster, retrofitted and tested up to the element failure to clarify the collapse motivations. Another TT beam was extracted from the roof of the industrial building, suitably retrofitted and also tested up to collapse. Even the thin-webbed Ω roof elements supported by the beams were investigated due to an excessive deflection produced by the only self-weight. Three of them were also extracted from the roof and tested up to collapse. They were retrofitted by using CFRP strips and suitable ties. The paper is focused on the discussion of the problem causes and their solution by using experimental and numerical evidences.