SBIR/STTR Award attributes
The Air Force stores some critical components in steel, cubic shaped chambers.These chambers are underground and are encased with reinforced concrete.There is no direct access to the concrete, making inspection very difficult.We propose to develop a nondestructive system to detect, locate, and assess degradation of reinforced concrete encasing the steel chambers.We propose use of piezoelectric based assessment of stress waves produced directly by degradation processes.Acoustic emission testing is well established for inspecting accessible reinforced concrete.We propose to adapt these methods to inspecting reinforced concrete behind steel plate.Concrete is highly attenuating so direct measurement on concrete require numerous sensors.We will test the ability of the steel plate to act as a waveguide for the AE energy, allowing effective concrete inspection with fewer sensors.Our LAHMPTM system will be modified specifically to perform the automated diagnostic and prognostic calculations developed in this research program.In Phase I we will: construct steel reinforced concrete blocks with steel plates on one side; accelerate damage to the blocks; piezoelectrically monitor the blocks both directly (on concrete) and indirectly (through steel plate); modify damage detection algorithms to account for the steel;customize LAHMP; and prepare for Phase II/III.
