The Reaction-to-fire Performance of Wood Covered with A Transparent Film: A Potential Method for the Preservation of Chinese Wooden Historical Buildings

To have a deep understanding of the influence of film covering on the reaction-to-fire performance of wooden samples, a series of tests were conducted to obtain the profile of heat release rate (HRR), the peak of HRR (p-HRR), total heat release rate (THR), time-averaged HRR (a-HRR) and time to ignition (TTI) by using a Cone measurement facility. The microstructure and the main element concentration were got by the EDX analysis of SEM. The woodgrain orientations of samples were radial (R type, beam) and longitudinal (L, column). Based on the analysis of test results, the film is believed to impact a big influence on the reaction-to-fire performance. In general, the p-HRR, a-HRR, and THR are increased. The TTI is shortened largely due to the organic film. However, the THR does not depend on the radiation levels for the wooden sample (L woodgrain) with a film. In addition, the fire performance of wooden samples depends on the types of woodgrain orientation due to the difference in thermal conductivity and charring ratio in radial and longitudinal woodgrains. It is concluded that nearly no additional element was introduced by film covering by comparing the main element concentration of film and the part that the film was removed. It hopes to propose a potential method for the preservation of wooden historical buildings.