NDT specifications to aid life cycle cost analyses of bridges

Frequently NDT of bridges has been undertaken on a negotiated basis, relying upon goodwill from both the employer and the NDT test house in order to achieve value for money and quality. When competitive tendering has been introduced into this arena, problems have arisen due to lack of a quantified basis for comparison. The objective of this paper is to address the issues of drawing up competitive tenders in order to obtain the best value for money price and more importantly improved quality from competing test houses. This paper focuses on NDT techniques to identify voiding in grouted post-tensioned bridge tendon ducts; and scour measurement at bridge sites - in order to illustrate the procedures for competitive tendering of an NDT contract. The procedure for preparing tender documents has been given. In addition, guidance has been given to the client as to how to monitor the role of an independent consultant undertaking the tendering process. Each step in this process will not only yield a more competitive price, but also yield a better quality of investigation as required by the Frangopol model.