Condition assessment of concrete structures generally involves Non-Destructive evaluation and response interpretation ranging from ultrasonic methods to sensor based impedance tracking. The level of sophistication required is ultimately decided by the complexity and importance of the structure. This research work examines the possibility of correlating microwave signatures with quality and strength parameters of concrete. By using microwave as the probing system it is possible to achieve higher penetration levels, wider coverage from a single measurement and more importantly far field non-contact measurements from the structure. All these advantages make microwave based sensing system as a promising future choice compared to conventional ultrasonic measurements. A comparison has been made between the microwave and ultrasonic measurements and a consistent relationship is identified to exist for various concrete grades ranging from M20 to M40. A simulation study has also been carried out by modelling the concrete medium in ABAQUS and the wave attenuation for various aggregate packing models has been obtained.

Keywords: Microwave sensing, Quality of concrete, Ultrasonic method, Acoustic simulation.