FIRE TESTS RESULTS OF DEFLECTION MEASUREMENTS OF REINFORCED CONCRETE STAIRCASE SAMPLES ANALYSIS

Abstract

In this work, the results obtained during the fire resistance tests of reinforced concrete staircases were analyzed, namely, the mechanical processes that take place in the inner layers of the material were studied, as well as the rate of growth and the maximum value of the deflection of the samples were analyzed. In the process of fire tests, the appearance of the limit state by fixing the loss of load-bearing capacity of samples of reinforced concrete staircases was not observed. Control of the formation of cracks according to the chosen method confirmed the absence of the appearance of cracks that would threaten the destruction of samples of reinforced concrete staircases. In general, according to the results of the fire tests, the studied samples correspond to the fire resistance class R 60. The maximum values of the deflection and the rate of growth of deformation were indicated. In addition, the results of the study of cracks and crushing of concrete of samples of reinforced concrete staircases during fire tests were analyzed. The obtained data allow us to conclude that the mechanical processes taking place in the inner layers correspond to theoretical ideas. Under the influence of heat in the test conditions, the examined samples of reinforced concrete staircases had bending deformation and the maximum deflection of the samples constantly increased downwards. On the temperature curves of the heating of the inner layers of samples of reinforced concrete staircases, there is a horizontal section with temperature indicators of about 100 ºС, which can be explained by the evaporation of the moisture present in the pores of the concrete