scholarly journals MODEL AND METHOD FOR CALCULATING THE RESOURCE OF REINFORCED CONCRETE ELEMENTS AND STRUCTURES

2021 ◽  
pp. 59-68
Author(s):  
V.M. Romashko ◽  
◽  
O.V. Romashko-Maistruk ◽  
Keyword(s):  
Reinforced Concrete ◽  
Potential Energy ◽  
Solid Mechanics ◽  
Residual Life ◽  
Energy Criterion ◽  
Force Model ◽  
Deformable Solid ◽  
Loading Mode ◽  
Deformation Force ◽  
Concrete Elements

Abstract. The article classifies, identifies and analyzes in detail the main disadvantages of existing models and methods for calculating the resource of building structure elements. A universal model and method for calculating the general and residual resources of reinforced concrete elements and structures that are under prolonged influence to operational loads are proposed. The generalized deformation-force model of the reinforced concrete elements and structures resistance to force effects is represented by an extended system of equations of the deformable solid mechanics. It is shown that the most important force and deformation parameters of the reinforced concrete elements state diagrams at all stages are functionally interconnected not only by rigidity, but by the potential energy of deformation. Therefore, due to the application of the hypothesis of invariability in a unit of volume and independence from the loading mode of the potential energy of their limiting deformation, this model has been developed to the energy level. The main advantages of the developed model of the reinforced concrete elements to force effects resistance in comparison with the existing force and deformation models in determining the resource of such elements are demonstrated. The methodology for calculating the general and residual life of reinforced concrete elements and structures is proposed to be built according to the deflections directly measured during field surveys or the step and width of the opening of normal cracks. In practice, they can be determined by geodetic, photogrammetric or any other means. The combination of the deformation-force model and the energy criterion makes it possible to calculate the general and residual resources of reinforced concrete elements and structures from a unified methodological standpoint. Therefore, the proposed "energy" hypothesis is recommended to be used as a universal energy criterion not only for the bearing strength exhaustion of the reinforced concrete elements, but also for limiting their deflections, as well as the width of the normal cracks opening under the action of any duration loads.

Residual Life Predication of Reinforced Concrete Elements Based on Time-Varying Reliability

2010 ◽  
Vol 163-167 ◽  
pp. 3258-3262 ◽  
Author(s):  
Jun Wang ◽  
Hong Guang Ji ◽  
Juan Juan Wang ◽  
Zi Jian Zhang
Keyword(s):  
Reinforced Concrete ◽  
Residual Life ◽  
Failure Criteria ◽  
Concrete Durability ◽  
Method Of Calculation ◽  
Concrete Members ◽  
Steel Bars ◽  
Probabilistic Density Function ◽  
Concrete Elements ◽  
Important Basis

Scientific prediction the residual life of existing reinforced concrete elements is an important basis for assessment the structures. The resistance probabilistic density function of reinforced concrete elements was proposed by analyzing the random processes of resistance attenuation of concrete and steel bars. Since the factors of concrete durability damaged and materials deterioration , considered practical conditions of service structures and durability failure criteria of concrete members, a method of calculation the residual life was given, which is verified reasonable through the engineering case.

scholarly journals Calculation of the crack resistance of reinforced concrete elements with allowance for the levels of normal crack formation

2018 ◽  
Vol 230 ◽  
pp. 02028 ◽  
Author(s):  
Vasyl Romashko ◽  
Olena Romashko
Keyword(s):  
Reinforced Concrete ◽  
Crack Resistance ◽  
Calculation Method ◽  
Solid Mechanics ◽  
Crack Formation ◽  
Crack Opening ◽  
Nonlinear Function ◽  
Experimental Investigations ◽  
Concrete Element ◽  
Concrete Elements

The separate experimental investigations results and the major drawbacks of existing methods of calculating the reinforced concrete elements crack resistance are considered in detail, taking into account the process of multilevel formation and crack opening. Based on the basic provisions of the deformation and strength model of concrete and reinforced concrete resistance, an engineering method for calculating the formation and disclosure of normal cracks in the reinforced concrete elements and structures at the operational stages of their deformation is proposed. It is implemented on the system of generally accepted static, geometric and physical relations of a deformed solid mechanics. The simplicity of the proposed calculation method is due to the use of the nonlinear function of the average stresses of the reinforcement bond with concrete on the sections of the reinforced concrete element between adjacent cracks. The main advantages of the developed calculation method in comparison with others are outlined.

scholarly journals Residual resource of power resistance during building structures deformation

2019 ◽  
Vol 135 ◽  
pp. 03009 ◽  
Author(s):  
Ekaterina Kuzina ◽  
Vladimir Rimshin ◽  
Alexey Neverov
Keyword(s):  
Reinforced Concrete ◽  
Cross Sections ◽  
Residual Life ◽  
Deformable Body ◽  
Bending Moment ◽  
Discrete Models ◽  
Building Structures ◽  
Resistance To Deformation ◽  
Concrete Elements ◽  
Research And Design

Modern scientific research and design developments, based on the fundamental principles of physics, mechanics and thermodynamics, are developing in a phenomenological direction. This implementation is found both in traditional integrated models of reinforced concrete using the advantages of computer technology, and in discrete models following the grid methods of solid deformable body mechanics. Discrete models in content and chronology over time are hereditary with respect to integral models. The theoretical basis for calculating the residual life of the force resistance to deformation, determines the stiffness of the cross sections of reinforced concrete elements with a maximum bending moment and with zero bending moment are presented in this article.

SETTING A DIAGRAM APPROACH TO CALCULATING VIBRATED, CENTRIFUGED AND VIBROCENTRIFUGED REINFORCED CONCRETE COLUMNS WITH A VARIATROPIC STRUCTURE

2020 ◽  
pp. 22-34
Author(s):  
Л. Р. Маилян ◽  
С. А. Стельмах ◽  
Е. М. Щербань ◽  
М. П. Нажуев
Keyword(s):  
Experimental Data ◽  
Reinforced Concrete ◽  
Bearing Capacity ◽  
Cross Section ◽  
Concrete Columns ◽  
Reinforced Concrete Columns ◽  
The Cross ◽  
Concrete Elements ◽  
Diagram Approach

Состояние проблемы. Железобетонные элементы изготавливаются, как правило, по трем основным технологиям - вибрированием, центрифугированием и виброцентрифугированием. Однако все основные расчетные зависимости для определения их несущей способности выведены, исходя из основного постулата - постоянства и равенства характеристик бетона по сечению, что реализуется лишь в вибрированных колоннах. Результаты. В рамках диаграммного подхода предложены итерационный, приближенный и упрощенный способы расчета несущей способности железобетонных вибрированных, центрифугированных и виброцентрифугированных колонн. Выводы. Расчет по диаграммному подходу показал существенно более подходящую сходимость с опытными данными, чем расчет по методике норм, а также дал лучшие результаты при использовании дифференциальных характеристик бетона, чем при использовании интегральных и, тем более, нормативных характеристик бетона. Statement of the problem. Reinforced concrete elements are typically manufactured according to three basic technologies - vibration, centrifugation and vibrocentrifugation. However, all the basic calculated dependencies for determining their bearing capacity were derived using the main postulate, i.e., the constancy and equality of the characteristics of concrete over the cross section, which is implemented only in vibrated columns. Results. Within the framework of the diagrammatic approach, iterative, approximate and simplified methods of calculating the bearing capacity of reinforced concrete vibrated, centrifuged and vibrocentrifuged columns are proposed. Conclusions. The calculation according to the diagrammatic approach showed a significantly better convergence with the experimental data than that using the method of norms, and also performs better when using differential characteristics of concrete than when employing integral and particularly standard characteristics of concrete.

A Version of the Failure Criterion Modification for Plane Concrete

2017 ◽  
Vol 755 ◽  
pp. 300-321 ◽  
Author(s):  
Volodymyr I. Korsun ◽  
Yu.Yu. Kalmykov ◽  
S.Yu. Makarenko
Keyword(s):  
Comparative Analysis ◽  
Solid Mechanics ◽  
Concrete Strength ◽  
Failure Criteria ◽  
Analytic Description ◽  
Deformable Solid ◽  
Theoretical Approaches ◽  
Concrete Failure ◽  
Stress States ◽  
Multiaxial Loadings

The paper is about the generally accepted in the deformable solid mechanics principles of constructing limiting surfaces of concrete strength in the principal stress space. The background and theoretical approaches taken by different researchers to describe the functions of deviatoric and meridional curves as the basic elements which determine the surface configuration of concrete strength were analyzed.There was carried out a comparative analysis of different authors’ suggestions on an analytic description of concrete strength for different stress states and a comparison of the developed criteria and the results of short-term tests of plane concrete under multiaxial loadings. Comparing the methods taken for developing the interpolation functions of deviatoric and meridional curves, it was inferred that the application of different approaches to the development of concrete failure criteria is effective. Keeping in mind the results of the comparative analysis of the prerequisites taken to develop the above failure criteria and the requirements of a better approximation of the experimental data, there are made new suggestions to describe concrete strength for the general case of stress state.

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