Pavement Engineering researchers at the University of Pittsburgh (Pitt) are currently pioneering the use of ultrasonic tomography for the non-destructive quality assessment of concrete pavements. The team is utilizing the state-of-the-art MIRA A1040 system, an ultrasonic tomograph featuring an array of 48 dry-point-contact (DPC) transducers operating at 50 kHz. This DPC technology is particularly significant because it allows for reliable field measurements on rough concrete surfaces without the need for liquid coupling or extensive surface preparation, overcoming a major limitation of traditional ultrasonic methods.
The core of the research involves evaluating concrete specimens, both control samples and those with incorporated defects, to refine the assessment methodology. By analyzing the raw ultrasonic signals, the Pitt team reconstructs B-scans using the Synthetic Aperture Focusing Technique (SAFT). This advanced processing allows them to create detailed, two-dimensional images of the concrete’s internal structure, confirming key indicators like the backwall reflection at the correct specimen thickness. This work quantifies concrete quality based on several key metrics, including signal uniformity and attenuation, energy concentration at reflector locations, and signal-to-backwall reflection characteristics.
The ultimate goal is to translate this complex B-scan data into an intuitive, easily understandable quality score. This metric would allow users—from field technicians to project managers—to interpret the results and determine the integrity of the pavement without needing specialized ultrasonic training. Building upon foundational studies by researchers like Hoegh, Khazanovich, and Yu (2011) on MIRA’s capabilities for thickness measurement and defect detection, the Pitt research is set to deliver a practical and reliable tool that significantly enhances the non-destructive quality control of concrete pavements, ensuring long-term durability and structural health.
Check more here: https://pavements.pitt.edu/