Problems in design of self-supporting floor system during construction

In order to promote the development of outer-jacketing structure, a self-supporting floor system during construction was proposed, in which the steel structure can carry load by itself. During the construction, the steel floor system formed by steel-truss primary beam and steel-box secondary beam carries the construction load, and during the service, the steel structure is encased in concrete to form the composite floor system to carry the new loads. This kind of composite has the merit of combining load-carrying capacity and construction measures together in outer-jacketing structures for adding stories. Combining with the reconstruction (extension) project of Suifenhe Qingyun Market, the design idea of concrete floor construction system is introduced and the method of prestressed encased steel truss concrete composite beam design is expatiated. Selection of frame column, embedded length of beam column connection and bond construction between primary beam and secondary beam are briefly introduced.