PASSIVE FIRE PROTECTION OF WOODEN CONSTRUCTIONS OF CHURCHES DOMES BY MEANS OF IMPREGNATING COMPOUNDS
Because of constructive and architectural features, domes of churches are difficult of access for firemen divisions. That is why the passive fire protection is recognized as a priority type of protection for domes. Such protection is defined by application of means which are put in advance and do not demand an additional mobilization during fire extinguishing. The basic functional task of passive fire-prevention protection of object is maintenance of a standard time of counteraction to fire occurrence or its delay at an initial stage until arrival of firemen divisions. In Ukraine such standard time is 5 minutes for cities and 12 minutes for countryside. The purpose of the given work is to define a possibility of application of fire-bio-protective impregnating compounds DSA-2 and Neomid 450-1 for passive fire-prevention protection of wooden constructions of churches domes. The object under research was the model of a dome constructed as 1/8 part of its real size with fire load of 8 MJ/m <sup>2</sup>. Wooden bars of the model were impregnated by compounds DSA-2 and Neomid 450-1. As a test place of fire it was used the standardized fire model of 21B type. As a fuel it was used the gasoline of A-92 mark; 4 litres of gasoline were resisted to burning at the standardized fire model during 300±15 s, and 10 litres — during 720±25 s. Tests shown that the model of dome impregnated by compound DSA-2 resisted to a fire of B class during 720 s. Wood was carbonized and further did not support burning. The wooden model impregnated by Neomid 450-1 resisted to fire of B class during 300 s. The mass burning of wood bars which caused destruction and full burnout of the dome model was began after 720 s. As the criterion of efficiency of wood fire protection by applying of impregnating compounds it was chosen the temperature of ignition of fire-protected wood. Correlation between quality factor of fire-protection processing of wood and time of flame resistance under conditions of passive fire-prevention protection of wooden constructions of churches domes.