Post-tensioning systems (previous and current)
The commercial use of prestressing in the UK began just before the Second World war. During and just after the war it was used to overcome material shortages. The early designs were mainly by refugee European engineers and the systems manufactured were not British. After about 1950 various British systems were developed.
A paper by Wally entitled Prestressing, which was published in 1996 (see References below) reviewed the early history of prestressed concrete. It discusses the materials used and the systems for pre- and post-tensioning in use, particularly in the early days, along with various applications.
Detailed information on systems available between 1940 and 1985 may be found in CIRIA Report 106. A number of the systems described ceased to be used after about the 1960s. Thus, when assessing an existing structure, identification of the type of anchorage used may give an indication of the age of the structure.
Information on how reinforcement has developed over the years is given in Concrete Society Technical Report 70, Historical approaches to the design of concrete buildings and structures.