Phase II year
2014
(last award dollars: 2017)
Phase II Amount
$1,451,961
During covert operations, the U.S. Army may be required to breach a concrete structure using a controlled explosion. When choosing the most effective charge size and placement, it is vital to perform a rapid field assessment of the material and structural properties of the target structure. However, high strength concrete materials (such as Ultra-High Performance Concrete), including steel fiber reinforcement, may decrease the reliability of existing assessment methods. Therefore, the Army is seeking a non-destructive evaluation (NDE) system which can connect with currently fielded Army systems to identify the following required information: concrete compressive strength ranging from 3 ksi to 30 ksi within ±3 ksi; wall thickness up to 6 ft within ±1 ft; presence and location of metal substructure (such as steel reinforcement) within 1 ft from the surface; and presence of fiber reinforcement. This project will utilize the commercially available NLA RECON (manufactured by NLA Diagnostics, LLC), which is rugged, portable, and field-ready NDE system. The NLA RECON will utilize ultrasonic pulse velocity, impact-echo, and pulse-echo to meet or exceed the Armys requirements. Validation and demonstration tests will be performed under laboratory conditions at North Carolina State University, and in the field on in-service concrete structures.
Keywords: Non-destructive evaluation, concrete characterization, ultrasonic pulse velocity, impact-echo, pulse-echo, ultrasonic attenuation, concrete strength, concrete thickness