The Highways Agency is managing a National Structures Programme for some 100 hinge deck structures - the design detail, used in the 1970s, is difficult to inspect and deterioration may occur unseen, and lead to eventual failure.
Non-destructive testing (NDT) techniques need to be developed to assess their condition, without the resort to destructive methods, as part of a management strategy for this type of structure.
This pilot development work complements laboratory based research and analytical assessment currently underway at TRL. In fact the University have made use of some of the TRL laboratory specimens.
The work has aimed to develop an acoustic testing technique, which has been used in other industries and for metallic structures, into a robust method that can be used reliably on site. It has built a database of characteristic acoustic signatures.