Objective Characterisation of Reinforced Concrete with Progressive Corrosion Defects Through Clustering and Thresholding of Infrared Images

•Condition of corrosion defects in reinforced concrete (RC) detectable by infrared thermography (IRT).•Analysis of the earliest possible stage for detection of corrosion defects in RC.•Contribution to differentiation of true concrete defects from other surface, or environmental effects.•Segmentation of IR images by the application of unsupervised k-means clustering.•Objective thresholding for quantification and characterisation of corrosion-affected concrete.