Speaking

Recognizing the potential deficiencies of older post-tensioned (PT) conditions, the Cincinnati Department of Transportation and Engineering (CDOTE) retained B&N to inspect, perform non-destructive testing (NDT), generate rehabilitation plans and provide construction inspection expertise during the construction phase of PT bridge 690.

The project started with in-depth inspections and was followed by an extensive search and review of past contract documents. Next, a post-tensioned inspection plan was created and served as the scope for the project’s second phase, which included:

• Risk-based protocols for NDT
• Tendon duct grout sampling
• Borescope testing of tendon duct voids for water and corrosion
• The number of NDT tests, testing protocols and repair procedures
• Long-term inspection and maintenance procedures
• Scope for repairs

The project’s third phase included generating repair plans for the structure based on the findings of the first two phases. The final phase included providing construction inspection expertise and preservation of the structure as part of the CDOTE construction inspection team of the PT repairs. The remedial grouting of the tendon duct voids was difficult due to the significant amount of loose grout in the voids. 100 of 170 borescope test locations revealed significant voids, as well as water at numerous locations. The project is currently entering into the final phase of construction rehabilitation.