Abstract. The research introduces a methodology of establishing indicators of fire safety of a building in relation to a guaranteed duration of steel fire-proof corrugated beams resistance in conditions of standard fire tests. Indicators of fire safety are also established in the assessment of design limits of steel fire-proof corrugated beams during design process, construction or maintenance of the building as well as in reducing economic costs when testing steel structures for fire resisting property. The suggested methodology introduces the system of actions aimed to design constructive fire protection of steel corrugated beams of buildings. Technological effect is achieved by conducting firing tests of steel construction by non-destructive methods; the evaluation of fire resistance of fire-proof elements of corrugated beams (corrugated web, upper and lower shelves) is identified by the least fire-proof element of a welded Ibeam. In this methodology fire resistance duration of the constituent elements of a welded I-beam with account of its fire protection ability is described with an analytic function taken as variables. These variables are intensity strength of stresses and the degree of fire protection of a compound element.

Ключевые слова: здания и сооружения, железо-бетонные конструкции, неразрушающие испытания, оценка огнестойкости, методика расчета, ресурсо-энергосбережение.

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При проведении судебно-медицинских экспертиз возникает необходимость определить механизм пере-ломов, формирующихся при различных вариантах трав-мирующих воздействий. Безусловно, чем выше точ-ность метода решения, тем большую доказатель -ную ценность для органов следствия приобретает экс-пертиза.Современные компьютерные технологии, конеч но-элементный анализ позволяют моделировать процесс раз-рушения максимально близко к реальным усло виям.Метод конечно-элементного анализа (от англ. -finite element analysis -FEA), широко используемый при реше-нии задач механики деформируемого твердого тела, элек-тро-и магнитостатики, газодинамики, а также других об-ластей физики, основан на использовании математиче-ского метода конечных элементов [1,2].Метод конечных элементов (МКЭ) -численный ме-тод решения дифференциальных уравнений с частными производными, а также интегральных уравнений при ре-шении задач прикладной физики [1,2]. Проведено моделирование процесса формирования разрушения большеберцовой кости в области диафиза и проксимального эпифиза методом конечно-элементного анализа. Изучена топография силовых напряжений на модели кости. Установлено, что при нагружении по оси кости и перпендикулярно ее поверхности в области верхней трети (область значительного преобладания губчатого вещества) образуется вдавленный перелом в месте травмирующего воздействия. При тех же условиях нагружения в средней трети (область значительного преобладания компактного вещества) образуется поперечный перелом.

The paper presents the results of an experimental investigation of statically determinable pre-stressed concrete beams with tension on concrete (using post-tension). The authors consider the existing practice of applying post-tension in reinforced concrete structures, the current regulatory documents of the Russian Federation containing information on the strength and deformation properties of post-tension. The paper contains information about the loading pattern, beam-fixing conditions, geometric characteristics of a reinforced concrete beam, physical characteristics of concrete and reinforcement of an experimental sample, technical characteristics of pre-stressed reinforcement. The authors present the research results using graphs of structural deflection changes under load, the distribution of relative strain along the depth of a concrete cross-section, as well as cracking and failure schemes of experimental samples. The research presented in the paper showed that the destruction of the samples occurred along a standard cross-section and was brittle. As a result of processing the results of experimental data, loads of crack formation and critical crack width were determined. The authors confirmed the effect of pre-stressing on crack resistance and the magnitude of the deflection of bent reinforced concrete elements.

Modern methods for reducing the combustibility of novolac, epoxy and epoxy novolac oligomers used for the production of structural foams are considered. The results of studies on the application of chlorinated resins as fi re-resistant matrix, polyphosphates, intumescent carbon, and hallocyde nanotubes as fi re retardants are presented.

Abstract. The paper presents an example of calculations of an assembled reinforced concrete hollow core slab of off-shuttering formation which has been reinforced with pre-stressed wire in its top and bottom areas. The numerical modelling of statically determinate pre-stressed assembled reinforced concrete hollow core slab exposed to short duration uniform loading is shown as a finite element model in PC "LIRA SAPR 2014 R3". This article contains information about the finite elements used, fixing conditions of the slab and of the order in which links between concrete and steel reinforcement were modelled. The calculation results are presented in the form of isofields of finite elements motion in this calculation model. Table 1 presents research results as a finite element model calculations according to the methodology given in specification documents.