Damage Detection in Concrete Using Synthetic Aperture Focusing Technique

— The detection of embedded objects inside the concrete has been of great importance to insure the durability. Ultrasonic reconstruction using synthetic aperture focusing technique (SAFT) allow to image the internal structure of concrete and its algorithm focuses ultrasonic signals received at aperture point by coherent superposition that provide a high-resolution image of the region of interest. Using SAFT, the representation of concrete volume can be reconstructed with great details, allowing detecting and localizing objects inside the concrete such as construction elements, damage of built-in components or flaws. The inhomogeneous structure of the concrete that lead to disturbing phenomena of the transmitted signal such as attenuation and structural noise are diminished using SAFT. Lab experiments show the behaviors of the elastic wave propagation in the concrete medium and the analysis has been carried out by using COMSOL multi-physics software. The time travel associated with acoustic wave propagation has been analyzed to tune COMSOL in order to detect objects inside the concrete. The results show that the elastic wave based scanning system incorporated with SAFT exhibit high potential in inspecting damage inside the concrete structure.