Case Study #3: Locating Voids in Grouted Tendon Ducts of a
Post-Tensioned Highway Bridge, Northeastern USA
Problem: Identify areas where there are full or
partial voids in the tendon ducts in post-tensioned
Results: In a preliminary test, Impact-Echo
identified areas of full or partial voids in three of
fourteen girders tested.
Verification: Tendon ducts were opened and
inspected. Photo (above right) shows duct identified by
impact-echo as ungrouted.
Outcome: Impact-Echo used to locate voids in
grouted tendon ducts throughout the bridge. Empty and
partial grouted ducts re-grouted.
Back to Case Studies