Precast concrete building skeleton - has beams formed with longitudinal and transverse channels receiving cables stressed by jacks pressing on spans

摘要

Each beam of the structure is divided into two channel-forming parts, thus providing ample space for the free threading of steel cables to effect prestressing. The linear cables run through the channels, while in the locations for columns they are pulled through holes previously prepared for this purpose in the columns. In the first prestressing stage, once the concrete has hardened on the joints, the linear cables are tensioned so as to avoid the occurrence of friction. The next stage of prestressing is effected, while the cables are still free and accessible in each channel, by means of a jack which vertically presses along any other location in each span.