Concrete Bridge Condition Assessment with Impact Echo Scanning

The paper discusses the use of the Impact Echo Scanning nondestructive evaluation (NDE) technique for quality assurance and condition assessment of the grouting of post-tensioned bridge ducts and concrete bridge decks. Both research and case history results are presented. Impact Echo Scanning was first done for detecting void/grout conditions in post-tensioned ducts. Recent research and development of a Bridge Deck Scanner using the Impact Echo Scanning technique is compared with Ground Penetrating Radar and Acoustic Chain Drag Sounding to identify concrete delaminations due to rebar corrosion. The research on both Impact Echo Scanning applications was sponsored by the US National Cooperative Highway Research Innovations Deserving Exploratory Analysis program. The use of the Bridge Deck Scanner to evaluate concrete deck conditions in terms of void/honeycomb and thickness is also discussed.