Evaluation of the possibility of using dynamic indentation of gypsum boards to determine the degree of thermal damage to structures received under fire conditions
DOI:
https://doi.org/10.33408/2519-237X.2023.7-2.164Keywords:
inspection of the fire site, gypsum board, thermal damage, shock-pulse method, seat of fireAbstract
Purpose. To determine the applicability of dynamic indentation of gypsum boards to assess the degree of thermal damage to structures under fire conditions. To highlight the main characteristics of equipment for indentation of gypsum boards used as fire protection of building structures.
Methods. Laboratory studies of samples of gypsum boards in the chamber electric furnace under temperature exposure. Dynamic indentation. Full factorial experiment.
Findings. The possibility of using dynamic indentation of gypsum boards to assess the degree of thermal damage to structures made with their use. It is shown that to determine the change in dynamic hardness due to thermal damage to the specified material, the use of cylindrical indenters is more preferable than conical indenters. Based on the results of a full factorial experiment, the mathematical model was obtained that describes the change in the depth of indentation of a steel cylindrical indenter into a gypsum board depending on its cross-sectional area, the compression force of the spring of the accelerator, the temperature value and the heating time of the material. The technical characteristics of the equipment intended for the introduction of the indenter into the researched material by creating a shock pulse (the cross-sectional area of the cylindrical indenter 12.6 mm2; the compression force of the accelerating device spring 130 N) were determined.
Application field of research. The obtained research results can be applied in the development of technical means for determining the degree of thermal damage to structures made of gypsum boards obtained under fire conditions.
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