Cracking of prestressed concrete structures: Modelisation, validation and interpretation

This paper discusses the influence of minimum reinforcement on the cracking behaviour of prestressed concrete structure. It deals with modelling of th e reclosing of cracks induced by a permanent compressive stress due to pres tress-induced Concrete, reinforcement and bond are described by a set of co nstitutive laws for loading and unloading taking into account the softening of cracked concrete and creep of the bond between steel and surrounding co ncrete. The computerized model allows to determine steel-to-concrete slip, bond stress, concrete stress and steel stress along the transmission length . It is also able to calculate the transmission length between the crack an d the homogenous section (state I). Good agreement was observed between the analytical model and the results of 11 large scale tests of RC & PC tie el ements performed at Swiss Federal Institute of Technology at Lausanne. This paper also presents some applications and conclusions of a large parametri c study performed using the analytical model.