INFLUENCE OF THE LOAD TRANFERENCE METHOD ON SHORT TUBE CONCRETE ELEMENTS FILLED WITH HIGH-STRENGTH CONCRETE Dr. sc. sciences L.I. Storozhenko, docent D.A. Yermolenko, graduate student O.V. Demchenko У статті наведено результати експериментальних досліджень коротких центральностиснутих конструктивних елементів із сталевих труб заповнених високоміцними бетонами залежно від передачі навантаження. Визначено несучу здатність, відносні деформації і встановлено характер руйнування залежно від способу завантаження та міцності бетонного осердя. Наведено характеристики застосованих матеріалів, зокрема розроблених складів високоміцних бетонів. Ключові слова: трубобетон, високоміцний бетон, несуча здатність В статье приведены результаты экспериментальных исследований коротких центрально-сжатых конструктивных элементов из стальных труб заполненных высокопрочными бетонами в зависимости от метода передачи нагрузки. Определено несущую способность, относительные деформации и установлен характер разрушения в зависимости от способа загрузки и прочности бетонного ядра. Приведены характеристики применяемых материалов, в частности разработанных составов высокопрочных бетонов. Ключевые слова: трубобетон, высокопрочный бетон, несущая способность.This article deals with advantages and disadvantages of use of concrete filled with steel tube structures with cores of high-strength concrete. Characteristics of used materials are shown, including the physical and mechanical properties of high-strength concrete compositions designed with using the local materials. Results of experiments of short centrally compressed structural elements of steel tubes filled with high-strength concrete and according to the load transference onto complex cross-section and concrete core are presented. It has been determined the capacity relatively the deformations and it has been found the fracture character according to the way of loading and concrete core strength. The method of transference of the load results in efficiency of tube concrete element from the high strong. Load transfer method impacts the efficient of high-strength concrete filled steel tubes structure element. Carrying capacity of test samples N1 increased by 8 -20% when load is transferred to concrete compared to complex cross-section. Longitudinal deformation decreases during the load transfer onto concrete core compared to complex cross-section load transfer.

The article presents experimental study results of the deformation state of composite cable space frame structures, including composite steel-concrete structures. Composite cable space frame structures are three-dimensional roof framing of long-span buildings. The designed constructions are a new type of roof framing structures and consist of typical composite steel-concrete modules connected with steel cable elements. The operation of composite cable space frame structures under load is characterised by geometric nonlinearity. The aim of the research is to study the deformation state and changing the geometric shape of experimental structures under the influence of external load. The technique of studying the deformation state of the composite cable space frame structures is based on the principles of digital photogrammetry. At the limit state the composite cable space frame structures change their regular shape. In this case, the central vertical points get the greatest vertical displacements, and the displacement value decreases closer to the supports. It is defined that the investigated construction has demonstrated combined action of all its components during the test, which indicates its effectiveness. The application of the photogrammetry method made possible to determine the moment of reaching the limit state of the composite cable space frame structures concretely.

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Abstract. Nowadays new trends are clearly manifested in building structures for buildings of various appointment and specific characteristics of their long-term operation. The priority in the construction industry takes place construction of high-rise residential and office buildings. Numerous studies in Ukraine and abroad proved that the construction of the frame with girderless floor provides resistance to both vertical and horizontal loads. It makes it possible to improve the traditional methods of frame building design. However, in the monolithic building of girderless floors there are a number of unresolved problems of structural, technological and organizational character. The authors have developed the construction of prefabricate reinforced concrete girderless floor that includes column drops, intercolumn slabs, span slabs. Column drops have bevelled lateral edges around the perimeter, forming a platform to support intercolumn slabs. Mounting of slabs occurs in the definite order. In the capacity of the columns it can be used as traditional prefabricated reinforced concrete structures as concrete filled steel tube ones. The advantage is that, comparing to modern reinforced concrete girderless floor, additional supporting equipment is not used during mounting slabs and scaffolding. The proposed girderless floors can be recommended for use in the construction of residential and public buildings for various purposes.

Stress-strain state and compressed flexible steel-reinforced concrete elements resistance capacity are investigated in the work. The experiment program is complied and steel reinforced concrete elements calculations methods are analyzed. Experimental sample design drawings are shown. Raw materials physical and mechanical properties are determined. Steel reinforced-concrete elements experimental and research studies have been carried out. Coboundary dependences N-M for steel reinforced concrete elements construction method is proposed. Resistance capacity diagrams for steel reinforced concrete elements are constructed depending on the element height and the applied eccentricity.