INFLUENCE OF PARAMETERS OF MEANS OF TEMPERATURE MEASUREMENT IN THE FURNACE ON THE RESULTS OF FIRE RESISTANCE TESTS OF BUILDING STRUCTURES AND PRODUCTS

Abstract

Due to the differences in the design of measuring instruments used according to national and European standards for measuring the temperature in the furnace, it is impossible to exclude inconsistencies in the creation of the same thermal effect on samples of test structures, which may affect the fire resistance test results of building structures and products, which are carried out according to national and European principles. This uncertainty led to a study of the influence of the parameters of the means of measuring the temperature in the furnace on the results of fire resistance tests of building structures and products, the results of which are presented in this article. The study aimed to assess the convergence of the results of fire resistance tests of building structures and products, obtained using different means of measuring the temperature in the furnace (rod thermocouples and plate thermometers), the parameters of which are given in national and European standards (DSTU B B.1.1-4-98* and EN 1363-1:2020). To achieve this goal, the problem of determining the difference between the readings of plate thermometers and rod thermocouples under fire conditions at standard temperature in the furnace and assess the change in time intervals to reach the fire resistance limit states of building structures and products for when used to measure plate temperature thermometers instead of rod thermocouples. It is shown that the highest values of the above difference, which is tens of percent, occur in the first five minutes of fire, and with increasing duration, this difference decreases significantly to several percent. It is established that when using plate thermometers to measure the temperature in the furnace, it is possible to predict shorter intervals before reaching the fire resistance limit states of structures in terms than when using rod thermocouples. The difference between the results of fire resistance tests obtained using plate thermometers and rod thermocouples may be the largest for building structures and products with a normalized period of time of classification for fire resistance, which is 15 minutes.