Although some early post-tensioned slab structures were constructed in Europe, the first real development of this method took place in the USA and Australia. The first post-tensioned slabs were erected in the USA in 1955, using unbonded post-tensioning. In succeeding years, numerous post-tensioned slabs were designed and constructed for use in the lift slab method of construction. Post- tensioning enabled the lifting weight to be reduced and deflection and cracking performance to be improved. Theoretical studies and experiments on post- tensioned plates were undertaken, and the joint efforts of researchers, design engineers and prestressing firms resulted in the introduction of standards and recommendations which helped to promote the widespread use of this form of construction in the USA and Australia. To date, more than 50 million m2 of slabs have been post-tensioned in the USA alone.
In Europe, the early 1970s saw a renewed interest in this form of construction, with some structures completed in Great Britain, the Netherlands and Switzerland. Intensive research work, especially in Switzerland, the Netherlands and Denmark and more recently in the Federal Republic of Germany, has expanded our knowledge of the behaviour of such structures. These studies form the basis for standards now in existence or in preparation in several countries. The method is now fully recognised in Europe and has already found considerable application, especially in the Netherlands, Great Britain, Switzerland and Germany.
