Time-Dependent Passive Building Thermography for Detecting Delamination of Adhered Ceramic Cladding

Time-dependent passive infrared thermography (td-PIRT) is an inspection technique that can be used to detect delamination. td-PIRT was used to inspect two buildings in Lisbon (Portugal) with adhered ceramic cladding to evaluate its potential to detect delamination problems in such claddings, which is a common problem and has safety risks. The td-PIRT data were analysed quantitatively by means of simple image subtraction (SIS), nonnegative matrix factorisation (NMF), and principal component analysis (PCA). Comparative evaluations showed that td-PIRT has a great potential to detect delamination problems in adhered ceramic cladding, depending on the analysis method selected. PCA and NMF were found to be efficient methods because of their good, consistent performance in revealing defective areas.