Concrete Bridge Design and Construction series No.3: Prestressing for concrete bridges

摘要

Of all the materials available to a bridge engineer, prestressing is the most challenging as it is an active, not passive, system. One cannot simply add more prestressing steel in order to be conservative, as the addition of prestress is just as likely to be detrimental to the section as is its removal. The designer must therefore calculate all the effects along all sections of the member, and then design the prestress to counter them at all locations. This process needs a determined effort from skilful designers, and throughout, they must consider the critical construction issues, as these affect all subsequent decisions.