Journal of Geography and Geology; Vol. 4, No. 4; 2012 ISSN 1916-9779 E-ISSN 1916-9787 Published by Canadian Center of Science and Education 1 Thermal Imaging as a Non Destructive Testing Implemented in Heritage Conservation Rodrigo Velázquez Castillo 1 , Miguel A. Pérez-Lara 1 , Eric Rivera-Muñoz 2 , José L. Arjona 3 , Mario E. Rodríguez-García 2 , Andrés Acosta-Osorio 1 & Miguel Galván-Ruiz 1 1 División de Investigación y Posgrado, Facultad de Ingeniería, Universidad Autónoma de Querétaro. CU Cerro de las Campanas, Querétaro, México 2 Centro de Física Aplicada y Tecnología Avanzada, Departamento de Nanotecnología, Universidad Nacional Autónoma de México Campus Juriquilla, Querétaro, México 3 FES Cuautitlán, Universidad Nacional Autónoma de México, Cuautitlán Izcalli, Estado de México, México Correspondence: Miguel Galván-Ruiz, Facultad de Ingeniería-Universidad Autónoma de Querétaro, CU Cerro de las Campanas S/N 76010, Querétaro, México. E-mail: mgr@uaq.edu.mx Received: September 12, 2012 Accepted: September 25, 2012 Abstract The aim of this work is analyzethe relevance of Non Destructive Technique (NDT) thermal infrared imaging (TIRI) as a way of reference to the heritage conservation.The assessment of thermography testing was done in order to evaluate the correspondence concerning the physical and chemical characterization and compatibility among original and restored plastered mortars and stuccos, considering the correlation betweenthermal emissivity values and other well-known materials characterization methods such as Fourier Transform Infrared (FTIR), X-ray diffraction (XRD) and Modulated Differential Scanning Calorimetry (MDSC) whichconclusively evidenced the appropriate assimilationof plasters and stuccosapplied inheritage conservation. Keywords: thermal imaging, non destructive testing, materials characterization, heritage conservation 1. Introduction According to the widely accepted Principles of the Conservation of Historic Buildings (British Standards Institution, 1998) which acknowledged the respect and conservation of the historic buildings as a priority, and in cases where a new-fangled material is introduced on behalf of forthcoming restoration.It must be compatible with the original materials color and appearance, in addition to physical, chemical and mechanical characteristics are required to be similar, in order to avoid incompatibility among them. The use of TIRI is an important technique for inspecting and performing non-destructive testing of construction elements, detecting where and how thermal energy is dispersing from a surface (Avdelidis & Moropoulou, 2004). Thermal Imaging applied is a non-destructive and non-invasive technique (Candoré, Bodnar, Detalle, & Grosse, 2010). The collected information is able to be used as part of procedures to identify heterogeneous character of materials and detect former construction interventions (Carosena, Carlomagno, & Giorleo, 2004). TIRI or Infrared thermography is recognized as a nondestructive testing (NDT) by the ACI committee 228 (ACI Committee 228, 1998, reapproved 2004) in section 2.7, being used in concrete construction for evaluation of the state of older concrete for rehabilitation purposes and quality assurance of concrete repairs. The use in several types of concrete structures such as bridge decks, highway pavement, parking garages and pipelines can be found in literature (Holt & Manning, 1978; Weil, 1989; 1991). In the same manner, the use of infrared thermography in concrete bridge decks is described in ASTM D4788 (ASTM International, 2007). The typical constructions of historical patrimonies are made of a variety of layered materials. Due to the thermal emission properties, the inside stratum can have consequences on the temperature distribution on the outer surface. It depends on the thickness and thermal properties of the first layer, as well as the thermal capacity of the layers inside. Dense and bulk materials can accumulate heat for a long time which can be visible on the surface, even if it originates from the inside. There is several research work published on restoration of plasters and stuccos (Toniolo, Paradisi, Goidanich, & Pennati, 2011; Quagliarini, Lenci, & Seri, 2012; Abrams, Parhamovich, Butcher, & McCord, 2012; Riquelme,