Characterization by thermogravimetric analysis of the wood used in Canary architectural heritage

In the interventions to historical heritage sites, it is necessary to have the characterization and identification of the raw materials in accordance with the architecture under study, in order to facilitate conservation and rehabilitation strategies. Pitch wood comes from the resinous heartwood of Pinus canariensis and is identity sign of traditional Canarian architecture. The aim of this work it is to check the usefulness of thermogravimetric analysis (TGA) as a test for the preliminary diagnosis of the presence of Pitch wood in traditional Canarian building. For this purpose, a study of the thermogravimetric behavior on wood samples taken from six buildings constructed between the 16th and 19th century was performed. TGA curves of these wood samples are compared with those obtained by analyzing the heartwood and sapwood of P. canariensis and samples of commercial wood. TGA results indicate that the Pitch wood has a singular behavior the first derivative of the thermogravimetric curve (DTG) with two peaks corresponding to the maximum rate of decomposition of hemicellulose and cellulose respectively. The first peak appears at a temperature of between 269 °C and 289 °C and the second peak of between 342 °C and 362 °C with a confidence interval of 95%. Pitch wood also has an effective density which differs by less than 10% of the value of the determined density using helium pycnometry.