Serviceability Design of Prestressed Concrete Bridges

Abstract

In this paper, serviceability limit states of prestressed concrete bridges are examined. Allowable compressive and tensile stresses in concrete under service loads are first used to determine the upper and lower limits of the longitudinal prestressing force. The same allowable stresses are used to define allowable shear stresses that prevent excessive tensile stresses in the principal tensile stress direction and that prevent excessive compressive stresses in the principal compressive stress direction. In some cases where the shear stresses due to service loads exceed the allowable shear stress, shear cracking may be controlled by transverse prestressing of the webs. Equations are presented to determine the required transverse prestressing force. An example concludes the paper.