THE OPTIMAL AMOUNT OF AIR FOR THE NATURAL VENTILATION OF CLASSROOMS AS A FUNCTION OF THE RATE OF OUTDOOR AIR LEAKAGE FROM WINDOWS

Abstract

In this paper, a reduction in the dynamic mechanical impact in Fert ceiling blocks with rubber filling is discussed. The research is conducted with the use of numerical methods based on the Finite Element Method (FEM). In order to observe the mechanical wave propagation in the form of stress plots, ADINA software is used. The analysis is performed with the use of a dynamic explicit module. Three different configurations of Fert concrete blocks are analyzed: Fert 40, Fert 45 and Fert 60. It is assumed that each block is subjected to a dynamic compressive pressure load applied to the top surface. The boundary conditions applied to the blocks represent simplified support on the concrete joists. In order to check how the rubber filling changes the mechanical wave energy transfer, blocks with and without rubber filler are analyzed. Through the analysis, it is shown that the larger the block size with rubber filling, the higher the reduction of mechanical wave energy transfer. Owing to that, the height of the insulation layer could be reduced to keep the same acoustic insulation parameters. On the other hand, the proposed rubber fill raises the overall mass of the blocks, which may negatively affect the ceiling bearing capacity.