Sensors Driven Mapping of Reinforcement Bars

Non destructive mapping of reinforcement may be needed in concrete elements of old buildings where changes or an extensive maintenance is required. It is needed if reliable design drawings are not available.The mapping will indicate the location of reinforcement bars, their size and depth of cover. The objectives of the study presented here were to select a reliable sensing tool for detection of the presence of reinforcement bars in concrete, and develop a reliable procedure for the manual and automated mapping of the reinforcement, with this tool. Different sensors may be used for detection of steel elements embedded in concrete. The sensors include electromagnetic covermeters, microwave (radar) scanners, radiographic systems, magnetic; and electrical devices. The sensor which has been selected for this study was an electromagnetic covermeter. To ascertain a fast and reliable scanning method, the sensor tool has been mounted on the arm of a robot (GMF-S 700) which led it through a predetermined grid of measurement points. An algorithm has been developed and tested for processing the data obtained, and generation of the layout of reinforcement. The paper discusses the testing of the sensor's accuracy, the manual and the robotized measurement process with the sensor and the principles of the algorithm for generation of reinforcement layout.