non destructive characterization of thermal and optical performances on high performances textiles

IR Thermography (IRT) has been widely used in the field of Cultural Heritage to study the thermal exchanges of open-air archaeological sites in which shelters increase the internal temperature and can induce changes in local microclimate. The present debate regarding the use of traditional shelters arose many doubts about their real effectiveness for protecting the ruins and for developing collateral dangerous effects, as the increase of temperature instead of its reduction underneath the shelter, the condensation of vapour along the colder surface (glass, steel etc.) and especially the excavation of archaeological soil for the anchorage of the foundation. The innovative use of textiles and ultra light structures (that do not require the excavation for setting the foundation) open new perspectives to the design of more effective shelters. Nevertheless, the application of textile is quite recent yet, and the scientific literature does not refer about the effect of polluted condition on the fabrics. The authors used visible-IR spectroscopy and IRT in an integrated approach to study the durability of the textile materials of shelters and to verify the real performances of innovative shelters exposed at severe climatic condition, This paper shows the results of tests on aged textiles at outdoor environmental conditions. The authors show also the simplified analytical models for the evolution of the optical properties due to ageing.