Control and calculation for upward deformation of prestressed concrete flexural member

In order to solve the problem that the control of deflection for prestressed concrete flexural member is not perfect in the current standards and references at home and abroad, combined with the actual practice, the allowable upward deformation was presented after calculation. The influence factors on upward deformation of prestressed concrete flexural member was analyzed, and the method through limiting the effective compressive stress to indirectly control the upward deformation of prestressed concrete flexural member was discussed. For prestressed concrete slabs, the allowable value for the effective compressive stress in the critical section was presented with the following influence factors: span, ratio of span to depth of section and the location of prestressed steel. For prestressed concrete beam, the variability of the effective compressive stress in the critical section was presented with the following influence factors: span, ratio of span to depth of section and load-bearing range. In addition, the calculation formulas of the allowable values for the effective compressive stress in the critical section of prestressed concrete beam were obtained.