A COLUMN SYSTEM WITH ARTICULATED JOINTS AND ELASTICALLY EMBEDDED DIAPHRAGMS

2015 ◽  
Vol 2 (1) ◽  
Author(s):  
Jiri Witzany ◽  
Daniel Makovicka ◽  
Radek Zigler ◽  
Tomas Cejka ◽  
Stanislav Pospisil ◽  
...  
Keyword(s):  
Reinforced Concrete ◽  
Dynamic Characteristics ◽  
Dynamic Testing ◽  
Seismic Effects ◽  
Load Bearing ◽  
Column System ◽  
Precast Column ◽  
Thin Walled ◽  
Natural Seismicity ◽  
Stiffness Adjustment

The spatial stability and controlled dynamic characteristics of an articulated precast column system are secured by thin-walled reinforced concrete diaphragms elastically embedded in some bays by means of special damping bearings. The intensity and the range of the load-bearing system’s response to dynamic (e.g. seismic) effects and vibrations are achieved by the stiffness adjustment of damping bearings. The stiffness of damping bearings may also be adjusted during exploitation. The designed structure with an elastically embedded diaphragm has been exposed to dynamic testing whose results are presented in the article. Another significant characteristic of the precast structure is its dry assembly and potential disassembly and relocation to another site. The experimental and theoretic analyses performed have confirmed the assumptions for the system’s application in areas with the occurrence of natural seismicity.

A PRECAST REINFORCED CONCRETE SYSTEM WITH CONTROLLED DYNAMIC PROPERTIES

2014 ◽  
Vol 1 (1) ◽  
Author(s):  
Jiří Witzany ◽  
Tomáš Čejka ◽  
Radek Zigler
Keyword(s):  
Reinforced Concrete ◽  
Dynamic Properties ◽  
Land Development ◽  
Essential Elements ◽  
Significant Feature ◽  
Load Bearing ◽  
Concrete System ◽  
Loading Effects ◽  
Natural Seismicity

The precast reinforced concrete system with controlled dynamic characteristics allows, together with demountability, an efficient optimization of a load-bearing system’s response to external dynamic and static loading effects and impacts. The essential elements of the system are the joints of load-bearing reinforced concrete precast units with high ductility allowing the absorption of dynamic energy and the optimization of the load-bearing system’s response to technical as well as natural seismicity. Another significant feature of such joints is their ability to eliminate outside noise (e.g., traffic, building activity, industrial activity) below the threshold of hearing; this improves the quality of the interior environment and allows land development in areas with increased noise levels, traffic, etc. The system may also be analogically applied in areas with poorer foundation conditions, in areas with underground traffic, in undermined areas, and in areas with high seismic risks.

scholarly journals ACCOUNTING THE STEEL PROFILE IN THE CALCULATIONS OF THE LOADING CAPABILITY OF STEEL-CONCRETE BEAMS

2019 ◽  
pp. 26-33
Author(s):  
N. Vinogradova
Keyword(s):  
Reinforced Concrete ◽  
Bearing Capacity ◽  
Concrete Beams ◽  
Experimental Studies ◽  
Structural Elements ◽  
Load Bearing Capacity ◽  
Load Bearing ◽  
External Reinforcement ◽  
Thin Walled ◽  
Monolithic Structure

Prefabricated monolithic floors are the best solution in terms of cost and time of work. In addition, due to the lightweight filling blocks included in the prefabricated monolithic structure, the overlap has less weight than the classic monolithic or precast slabs. Within the framework of this article, elements of prefabricated monolithic floors — reinforced concrete T-beams with a steel thin-walled profile, which is used primarily as formwork at the stage of construction and installation works, are calculated. Nevertheless, the calculation of the steel profile as an external reinforcement increases the load-bearing capacity of the beams by 50%. To assess the fact effect of the steel thin-walled profile on the strength characteristics of structural elements, experimental studies are conducted. According to the results of the experiment, it is found that the contribution of the steel thin-walled profile to the bearing capacity of the beams is 15%, while if the profile slip due to anchoring in the supporting zones is reduced, the bearing capacity increases by 50-60% compared to similar beams without a profile

Experimental Verification of Demountable Precast Column System

2016 ◽  
Vol 827 ◽  
pp. 259-262 ◽  
Author(s):  
Aleš Polák
Keyword(s):  
Reinforced Concrete ◽  
Experimental Verification ◽  
Negative Impact ◽  
Point Of View ◽  
Column System ◽  
Precast Column ◽  
Repeated Use ◽  
Precast Structures ◽  
Precast Elements ◽  
Steel Joints

Relocation of existing concrete structures requires full or partial demolition, which consumes a lot of energy and thus has a negative impact on the environment. From environmental point of view, demountable precast structures are sustainable. They allow “recycling” to the level of precast elements and so they save significant amounts of energy and materials. Another advantage of these structures is quick assembly without wet processes. A characteristic component of precast reinforced concrete construction system for multi-storey buildings are demountable joints of load-bearing precast reinforced concrete elements. This paper is focused on experimental verification of demountable precast column structure and its demountable steel joints. The experimental research was carried out within TA02010837 “Multipurpose dismantleable prefabricated reinforced concrete building system with controlled joint properties and possibility of repeated use”.

Seismic effects on large reinforced concrete lifelines—I. Theory

1992 ◽  
Vol 42 (2) ◽  
pp. 129-135 ◽  
Author(s):  
Y. Chen ◽  
T. Krauthammer
Keyword(s):  
Reinforced Concrete ◽  
Seismic Effects

INFLUENCE OF GAS-DYNAMIC TESTING RIG PIPELINES MATERIAL ON THEIR DYNAMIC CHARACTERISTICS

2021 ◽  
pp. 118-125
Author(s):  
А.В. Саврико ◽  
С.Н. Лымич ◽  
К.В. Кружаев ◽  
В.С. Левин ◽  
А.В. Москвичев
Keyword(s):  
Flow Rate ◽  
Dynamic Characteristics ◽  
Dynamic Testing ◽  
Analytical Calculation ◽  
Working Fluid ◽  
Factors Affecting ◽  
Pressure Losses ◽  
Steel Pipes ◽  
Gas Dynamic ◽  
Friction Pressure

Приведено исследование зависимости газодинамических характеристик стенда от применяемого материала трубопровода. Oсновополагающими факторами, влияющими на работоспособность стенда, являются выходные параметры - давление и расход рабочего тела, которые напрямую зависят от потерь давления на трение, создаваемого элементами стенда. Для оценки степени влияния материалов на потери стенда выбраны два вида труб: полипропиленовые и металлические. Аналитические расчёты потери давления рассматриваемых трубопроводов из различного материала показали, что трубопроводы из полипропилена предпочтительнее. Однако при проведении эксперимента получены противоположные данные, которые показали, что в полипропиленовых магистралях возможно присутствие значительного количества диафрагм: в местах пайки труб, образовавшихся в процессе изготовления. Именно этот факт способствует существенному повышению значений сопротивлений в полипропиленовых трубопроводах на 20 % по сравнению со стальными трубами, где диафрагмы отсутствуют. В результате проведения исследования был введен коэффициент, учитывающий влияние диафрагм полипропиленового трубопровода при аналитическом расчете на сопротивление. Для сохранения более точных снимаемых значений с газодинамических стендов целесообразнее использовать трубопроводы из металла, в которых рассчитать потери возможно с отклонениями до 3 % Here we give the study of the dependence of the gas-dynamic characteristics of the stand on the pipeline material used. The fundamental factors affecting the performance of the stand are the output parameters-the pressure and flow rate of the working fluid, which directly depend on the friction pressure losses created by the elements of the stand. To assess the degree of influence of materials on the losses of the stand, we selected two types of pipes: polypropylene and metal. Analytical calculations of the pressure loss of the considered pipelines made of various materials have shown that pipelines made of polypropylene are preferable. However, during the experiment, we obtained the opposite data, which showed that a significant number of diaphragms may be present in polypropylene pipelines: in the places of soldering of pipes formed during the manufacturing process. This fact contributes to a significant increase in the resistance values in polypropylene pipelines by 20 % compared to steel pipes, where there are no diaphragms. As a result of the study, we introduced a coefficient that takes into account the influence of polypropylene pipeline diaphragms in the analytical calculation of resistance. To preserve more accurate values taken from gas-dynamic stands, it is more expedient to use metal pipelines in which it is possible to calculate losses with deviations of up to 3 %

scholarly journals Modeling of joint work of steel beam constructions with reinforced concrete ribbed floor slabs

2021 ◽  
pp. 44-57
Author(s):  
Yevhen Dmytrenko
Keyword(s):  
Reinforced Concrete ◽  
Cross Section ◽  
Precast Concrete ◽  
Concrete Slabs ◽  
Effective Width ◽  
Joint Work ◽  
Load Bearing ◽  
Reinforced Concrete Slabs ◽  
Industrial Buildings ◽  
Floor Slabs

Traditional methods of calculation of beam constructions of floors and coverings of industrial buildings assume their consideration when calculating separately from the frame structures, in particular, reinforced concrete slabs, without taking into account their joint work, which leads to a significant margin of safety. Today in Ukraine there is a significant number of industrial buildings and structures that need strengthening and reconstruction. In this regard, of particular importance are studies of the actual load-bearing capacity of the frames of single-storey and multi-storey industrial buildings, and both in the reconstruction and in new construction, the results of which will significantly reduce costs and more rationally design structures. At the same time, one of the most relevant areas is the study of the joint work of metal load-bearing structures with prefabricated reinforced concrete structures of rigid disks of coatings and floors in their calculation.           Moreover, in the national building codes, as well as in the educational and methodological literature, the calculation methods of taking into account the joint work of such constructions are not fully covered. The purpose of this work is to estimate the reduction of mass of the metal beam structure in its calculation in bending, taking into account the joint work with the rigid disk of the floor consist of precast concrete. As part of the study, the calculation of the floor beam according to the traditional calculation scheme - without taking into account the joint work with the floor slab, the calculation of its cross-section taking into account the joint work with floor slabs and experimental numerical study of the floor by the finite element method. Modeling of the floor fragment was performed in the software packages "SCAD Office" and "LIRA CAD 2019". Numerical research is aimed at verifying the feasibility of using the calculation methodology of DBN B.2.6-98-2009 to determine the effective width of the shelf when calculating the T-sections for prefabricated reinforced concrete slabs, which are included in the joint work with the floor beams. A comparative analysis of the obtained cross-section of the beam with the beam which was previously calculated by the traditional method of calculation  in stresses in the most dangerous cross section and the total mass of the beams. According to the results of the analysis, the correctness of the application of the above normative method for determining the effective width of the shelf of T-bending reinforced concrete elements was confirmed.

Sign in / Sign up

Export Citation Format

Share Document