Nondestructive Concrete Characterization System

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, recent advances in manufacturing high strength concrete materials (such as Ductal) may increase the uncertainty of these assessment methods. Therefore, the Army is seeking a non-destructive evaluation (NDE) system which can connect with currently fielded Army systems and identify the following required information: compressive strength of in-situ concrete from 3 ksi to 30 ksi within +/- 3 ksi; wall thickness up to 6 ft with an accuracy of 1 ft; presence and location of metal substructure (such as steel reinforcement) within 1ft from the wall 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 a field-ready NDE system. The NLA RECON will utilize ultrasonic pulse velocity, impact-echo, pulse-echo, and ultrasonic attenuation to meet or exceed the Army"s requirements. Tests will be performed on a selected set of concrete samples, built by North Carolina State University.