Sensing technology for functional maintenance of elevated railway structure

Experimental investigations on the construction of real railway structures using reinforced concrete are performed by using the active infrared thermography technique. A remote heating system consisting of an air-cooled 6 kW xenon arc lamp and a scanner system is developed. The heating system can be used to detect hidden defect in the concrete structure at depths less than 30 mm; for the detection, an irradiation with an energy density of 0.92 kJ/m². Results obtained from the experiments show that the proposed method provides better performance than conventional passive infrared thermography, irrespective of the weather conditions.