Determination of influence of thermal exposure duration on glass roughness byatomic force microscopy

When determining the location of the fire source and establishing local temperatures in the fire zone inside the building, window panes are often objects of expert research. By their nature, glasses have various physicochemical properties (optical characteristics, hardness, etc.), various internal (structure, defects, inclusions) and external (surface quality, presence of coatings) structures. Under fire conditions, under thermal and mechanical action, these properties may vary. The results of studying the microrelief of the glass surface subjected to heat treatment at different temperatures and heating times by atomic force microscopy are presented. Histograms of values of image elements (elevations of relief) were constructed based on results of scanning of samples relief and values of arithmetic mean and square mean roughness of glass surface before and after heat treatment were calculated. It has been found that the roughness of the glass surface decreases during the heat treatment process. The further development of studies by atomic force microscopy of window glass fragments that have been in the fire zone may make it possible to establish the temperature to which the glass fragments were subjected. The location of such fragments in the completed fire zone may indicate the direction to the location of the hottest combustion zone in accordance with a decrease in the roughness values of the window glass fragments that have been in the combustion zone.