The authors proposed a new calculation method of long-term deflection of floor slabs. By this method, long-term deflections can be calculated under a unified conception and method between prestressed(PC), partially prestressed(PPC), and reinforced concrete floor slabs. It is an application of the "Load Balanced" design method. In the method, for the "residual load" which is the difference of total design load and the balanced load, the long-term deflections are calculated as a reinforced slab. In the study a long-term deflection experiment was conducted using two PPC concrete slabs and one reinforced concrete slab having 13 meter effective span. Using the proposed model, the calculated deflections were compared with experimental ones. As a result, the proposed method can calculate long-term deflections of PC and PPC floor slabs in good accuracy.
