scholarly journals Experimental studies of multilevel formation of normal cracks in reinforced concrete elements

2019 ◽  
Vol 1 (4) ◽  
pp. 28-38
Author(s):  
Olexandr Zhuravsky ◽  
Olena Romashko-Maistruk
Keyword(s):  
Reinforced Concrete ◽  
Experimental Studies ◽  
Concrete Elements

Using of Plastic Hinges in the Calculation of Buildings against Progressive Collapse under Fire Exposure

2018 ◽  
Vol 878 ◽  
pp. 115-120
Author(s):  
Levon Avetisyan
Keyword(s):  
Reinforced Concrete ◽  
Progressive Collapse ◽  
Experimental Studies ◽  
Fire Exposure ◽  
Reinforced Concrete Frame ◽  
Dynamic Calculation ◽  
Plastic Hinges ◽  
Concrete Frame ◽  
In Fire ◽  
Concrete Elements

This article presents a study of the strength of a 25-storey reinforced concrete frame against progressive collapse in fire conditions. Taking into account the angles of disclosure of plastic hinges as norming for the strength of reinforced concrete elements, a computer technology program has been developed and included in PR Wolfram Mathematica 10 for the dynamic calculation of compressed reinforced concrete elements under fire exposure on the basis of the conducted experimental studies. Dynamic calculation of the strength of eccentrically compressed reinforced concrete columns was carried out, with operation in normal conditions and under high temperatures. The diagram «moment-curvature» and the graph of the change of the static and dynamic strength of the column depending on the temperature were developed. Nonlinear dynamic analysis of a 25-storey reinforced concrete frame was conducted, taking into account the changes of the dynamic characteristics of reinforced concrete elements in fire and, the estimation of resistance of the frame was given.

scholarly journals Design Model Of Bending Reinforced Concrete Elements Under Action Of Transverse Forces Under Conditions Of Increased And High Temperatures

2020 ◽  
Vol 02 (10) ◽  
pp. 17-24
Author(s):  
Mahkamov Y.M. ◽  
Keyword(s):  
Reinforced Concrete ◽  
Crack Resistance ◽  
High Temperatures ◽  
Experimental Studies ◽  
Calculation Model ◽  
Design Model ◽  
Stress Strain ◽  
Concrete Elements

In this article, the calculation of the strength and crack resistance of bending elements operating under conditions of high and high temperatures and transverse forces are proposed to be carried out according to a calculation model developed based on an analysis of experimental studies that takes into account more correctly the physics of the stress-strain phenomenon of the element.

scholarly journals Improved engineering method for calculating the strength of the supporting areas of reinforced concrete elements

2018 ◽  
Vol 230 ◽  
pp. 02014 ◽  
Author(s):  
Olena Krantovska ◽  
Mykola Petrov ◽  
Liubov Ksonshkevych ◽  
Sergii Synii ◽  
Pavlo Sunak
Keyword(s):  
Reinforced Concrete ◽  
Comparative Analysis ◽  
Cross Sections ◽  
Experimental Studies ◽  
Engineering Calculation ◽  
Standard Methods ◽  
Refined Method ◽  
Eurocode 2 ◽  
The World ◽  
Concrete Elements

According to the results of experimental studies, empirical dependencies were obtained (obtained from the appropriate mathematical models). The advanced (refined) method of engineering calculation of express-estimation of the strength of sloping cross sections of elements of flexible reinforced concrete structures on the basis of comparative analysis of the obtained empirical dependencies and standard accepted methods in the world was developed (nine basic norms are taken: DSTU B.V.2.6-156:2010 (Ukraine), previously operating SNiP 2.03.01-84*, SNB 5.03.01-02 (Belarus), SR 63.13330.2012 (Russia), Eurocode 2, 2004 (European Union), ACI 318-M14 (USA), AIJ Code, 2007 (Japan), CSA 23.3-04 (Canada), DIN 1045-1 (Germany). The coefficient of variation of bearing capacity and accident ratio according to the results of calculations of standard methods are determined. Their comparative analysis is carried out and informative graphic figures are presented.

scholarly journals Numerical and experimental studies of bent elements of basalt fiber reinforced concrete with prestressed glass composite reinforcement under static and short-term dynamic loads

2019 ◽  
Vol 221 ◽  
pp. 01026
Author(s):  
Vasilii Plevkov ◽  
Konstantin Kudyakov
Keyword(s):  
Reinforced Concrete ◽  
Experimental Studies ◽  
Basalt Fiber ◽  
Fiber Reinforced Concrete ◽  
Fiber Reinforced ◽  
Dynamic Effects ◽  
Glass Composite ◽  
Short Term ◽  
Concrete Elements ◽  
Composite Reinforcement

The article shows studies of bending basalt fiber reinforced concrete elements with pre-stressed glass composite reinforcement under static and short-term dynamic effects. Main results of numerical and experimental studies are presented. It is experimentally established and theoretically confirmed that a significant increase in the strength and crack resistance of the normal sections of concrete bent elements is observed when using basalt fiber reinforcement and pre-stressed glass composite reinforcement.

scholarly journals ANALYSIS OF STRENGTHENING OF COMPRESSED REINFORCED CONCRETE STRUCTURES USING REINFORCED CONCRETE JACKETS / GNIUŽDOMŲJŲ GELŽBETONINIŲ KONSTRUKCIJŲ STIPRINIMO GELŽBETONINIAIS APVALKALAIS ANALIZĖ

2011 ◽  
Vol 3 (2) ◽  
pp. 76-84
Author(s):  
Saulius Pilkavičius
Keyword(s):  
Reinforced Concrete ◽  
Carrying Capacity ◽  
Theoretical Calculations ◽  
Experimental Studies ◽  
Calculation Methods ◽  
Advantages And Disadvantages ◽  
Calculation Algorithms ◽  
Capacity Calculation ◽  
Basic Equations ◽  
Concrete Elements

This article investigates two chosen calculation methods of compressed reinforced concrete elements strengthened using reinforced concrete jackets. Shortly describe carrying capacity calculation algorithms of these calculation methods. Present elements basic equations and dependences of carrying capacity. For calculation methods of carrying capacity comparison and adjustment executed carrying capacity experimental studies of compressed fiber reinforcement concrete elements strengthened using reinforcement concrete jackets. Were compared theoretical calculations of carrying capacity results with experimental carrying capacity results. Shortly describe advantages and disadvantages of analyzed calculation methods and experimental research. By the comparison of calculation methods conclusions and experimental studies conclusions, produces improved calculation method of carrying capacity.

Strength of Normal and Inclined Sections of Bent Reinforced Concrete Elements with Zone Reinforcement Made of Steel Fiber

2022 ◽  
Vol 906 ◽  
pp. 7-15
Author(s):  
Dmitry Utkin
Keyword(s):  
Reinforced Concrete ◽  
Dynamic Loading ◽  
Calculation Method ◽  
Steel Fiber ◽  
Experimental Studies ◽  
Concrete Structures ◽  
Dynamic Loads ◽  
Reinforced Concrete Structures ◽  
Short Term ◽  
Concrete Elements

On the basis of theoretical and experimental studies, the prerequisites and the method of calculation of bent and compressed-curved reinforced concrete structures with zone reinforcement made of steel fiber, working under static and short-term dynamic loads, are formulated. In the developed method for calculating the strength of normal and inclined sections, a nonlinear deformation model is implemented, which is based on the actual deformation diagrams of materials. The developed calculation method is brought to the program of calculation of reinforced concrete structures with zone reinforcement of steel fiber under short-term dynamic loading, taking into account the inelastic properties of materials. The numerical studies made it possible to determine the influence of various parameters of steel-fiber reinforcement on the strength of reinforced concrete elements. To confirm the main results of the developed calculation method, experimental studies of reinforced concrete beam structures reinforced with conventional reinforcement and a zone steel-fiber layer are planned and carried out. Experimental studies were carried out under static and short-term dynamic loads. As a result of the conducted experiments, data were obtained that characterize the process of destruction, deformation and cracking of steel-reinforced concrete elements under such types of loading. The dependences of changes in the energy intensity of reinforced concrete structures with zone reinforcement made of steel fiber in the compressed and stretched cross-section zones under dynamic loading are obtained. The effectiveness of the use of fiber reinforcement of normal and inclined sections of bent and compressed-curved elements to improve the strength and deformative.

scholarly journals EXPERIMENTAL STUDIES ON THE INFLUENCE OF TRANSVERSE REINFORCEMENT FOR STRENGTH OF COMPRESSED REINFORCED CONCRETE ELEMENTS

2021 ◽  
Vol 10 (4) ◽  
pp. 21-28
Author(s):  
Sergey S. MORDOVSKIY ◽  
Kamil B. SHARAFUTDINOV
Keyword(s):  
Reinforced Concrete ◽  
Bearing Capacity ◽  
Experimental Studies ◽  
Longitudinal Force ◽  
Concrete Sample ◽  
Transverse Reinforcement ◽  
Direct Factor ◽  
Rectangular Cell ◽  
Concrete Elements ◽  
Zigzag Type

The infl uence of transverse reinforcement, including indirect reinforcement, on the strength of compressed reinforced concrete elements is analyzed. This question arose in connection with the possibility of increasing the strength of short reinforced concrete elements loaded with a longitudinal force with small eccentricities within the section of the element. For such elements, the cage eff ect may appear, associated with the coeffi cient of transverse deformations, the magnitude of which is a direct factor in the destruction of the concrete sample, and the limitation of these directly aff ects the bearing capacity of the sample in the direction of increase. The infl uence of transverse reinforcement in the form of stirrups located with diff erent spacing, as well as indirect reinforcement in the form of meshes with a classical rectangular cell and meshes of the “zigzag” type is considered.

scholarly journals RESEARCH OF THE INFLUENCE OF LONGITUDINAL COMPRESSION ON THE STRENGTH OF THE WALL OF TWO-TURNED REINFORCED CONCRETE ELEMENTS WITH A CHARACTERISTIC EPURA BENDING MOMENTS IN THE AREA OF ACTION OF LATERAL FORCES

2021 ◽  
Vol 3 (72) ◽  
pp. 34-37
Author(s):  
A. Abdullaev .
Keyword(s):  
Reinforced Concrete ◽  
Concrete Beams ◽  
Experimental Studies ◽  
Compressive Force ◽  
Reinforced Concrete Beams ◽  
Bending Moments ◽  
Shear Forces ◽  
Longitudinal Compression ◽  
Lateral Forces ◽  
Concrete Elements

Experimental studies have been carried out to study the effect of longitudinal compression on the strength of the wall of I-beams of reinforced concrete beams.It has been established that with the central application of a longitudinal compressive force, the strength of the wall of I-beams of reinforced concrete beams with an alternating diagram of bending moments in the zone of action of transverse forces practically depends little on the degree of longitudinal compression.A comparative analysis of the results obtained with the results of similar experimental studies carried out on I-beam reinforced concrete beams with an unambiguous diagram of bending moments in the zone of action of shear forces is carried out.

scholarly journals CAPACITY FLEXIBLE COMPRESSED REINFORCED CONCRETE ELEMENTS REINFORCED WITH STEEL SHEETS

2018 ◽  
Vol 1 (50) ◽  
pp. 79-87
Author(s):  
L. I. Storozhenko ◽  
S. O. Murza ◽  
О. І. Yefimenko
Keyword(s):  
Reinforced Concrete ◽  
Bearing Capacity ◽  
Carrying Capacity ◽  
Applied Load ◽  
Experimental Studies ◽  
Load Bearing Capacity ◽  
Steel Reinforced Concrete ◽  
Steel Sheets ◽  
Dependence Graphs ◽  
Concrete Elements

The experimental studies results of reinforced concrete elements with sheet reinforcement load bearing capacity are presented. The drawing of experimental designs is shown. The bearing capacity dependence graphs of the tested steel-reinforced concrete samples with sheet reinforcement on the height of the element and dependence graphs of tested steel-reinforced concrete samples with sheet reinforcement carrying capacity on the applied eccentricity are constructed. The photo shows the destruction character of experimental steel-concrete samples with sheet reinforcement depending on their height. The general schedule of bearing capacity dependence on the height of the element and the eccentricity of the applied load is constructed.

scholarly journals THE STUDY OF LEVEL FORMATION AND DISCLOSURE OF NORMAL CRACKS IN REINFORCED CONCRETE ELEMENTS

2020 ◽  
Vol 4 (157) ◽  
pp. 18-24
Author(s):  
O. Romashko-Maistruk
Keyword(s):  
Reinforced Concrete ◽  
Concrete Beams ◽  
Experimental Studies ◽  
Nonlinear Function ◽  
Reinforced Concrete Beams ◽  
The Real ◽  
European Standards ◽  
And Storage ◽  
Concrete Elements ◽  
Formation Step

This article is devoted to the study of the main patterns of normal cracks multilevel formation in reinforced concrete elements and structures. A critical analysis of the latest publications related to the theme of these studies is carried out. The classification is carried out and the main shortcomings of the known works on the four identified areas of research are identified. The most important elements of the method of reinforced concrete beams experimental research are developed and briefly described. The main characteristics of the prototypes, the conditions for their manufacture and storage are given. The most important results of testing reinforced concrete beams, concerning the main parameters and characteristics of level formation and crack disclosure are highlighted. It was confirmed that the process of normal cracks formation is indeed multilevel and is accompanied by a gradual disruption of the bond between reinforcement and concrete. According to the results of experimental studies, it has been established that in the real design of bending reinforced concrete elements, when calculating their crack resistance, it is possible to restrict oneself to only 2 levels of normal cracking. The calculation of the step and normal cracks opening width in beams research was carried out according to the real multilevel and traditional "one-level" schemes of their formation. These calculations were carried out according to the author's general and simplified methods, according to a method that uses a linear function of the average adhesion stresses of reinforcement with concrete, according to the methods of current domestic and European standards and building rules. Their statistical comparison with the experimental studies results confirmed the effectiveness of those calculation methods in which the crack formation step is directly related to the basic laws and parameters of reinforcement to concrete adhesion. The results of this comparison showed that the author's general method, based on the use of a nonlinear function of the reinforcement with concrete average adhesion stresses, turned out to be the most accurate. Keywords: reinforced concrete, elements, adhesion, reinforcement, cracks, levels of formation, step, width.

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