Stress-strain state of corrosion-damaged reinforced concrete elements under dynamic loading

2019 ◽  
pp. 19-26
Keyword(s):  
Reinforced Concrete ◽  
Strain State ◽  
Concrete Beam ◽  
Reinforced Concrete Beam ◽  
Stress Strain ◽  
Static Loads ◽  
Software Complex ◽  
Stress Strain State ◽  
The Impact ◽  
Concrete Elements

The solution of problems of survivability of reinforced concrete elements at beyond design impacts caused by simultaneous manifestation of power and environmental factors is necessary in modern realities. The impact of external aggressive environments, the operation of buildings without timely repairs is the cause of corrosion processes in reinforced concrete elements, which leads to a decrease in their bearing capacity and, as a consequence, reduction in the life of buildings. Currently, one of the urgent problems is the actual work of corrosion-damaged reinforced concrete elements under the impact of dynamic and static loads. The bendable reinforced concrete beam locally damaged in the compressed part of the cross-section is considered. Using modern computing software complex, it was carried out the comparative evaluation of the stress-strain state of an undamaged and corrosion-damaged reinforced concrete elements under dynamic and static loading. The influence of the weakened by corrosion concrete part of the compressed area on the redistribution of stresses in the section is analyzed.

scholarly journals THE STRENGTH OF REINFORCED CONCRETE BEAM ELEMENTS UNDER CYCLIC ALTERNATING LOADING AND LOW CYCLE LOAD OF CONSTANT SIGN

Vestnik MGSU ◽  
2015 ◽  
pp. 36-50 ◽  
Author(s):  
Yuliya Anatol'evna Semina
Keyword(s):  
Reinforced Concrete ◽  
Crack Resistance ◽  
Strain State ◽  
Concrete Beam ◽  
Reinforced Concrete Beam ◽  
Constant Sign ◽  
Stress Strain ◽  
Beam Elements ◽  
Stress Strain State ◽  
The Impact

The behavior of reinforced concrete elements under some types of cyclic loads is described in the paper. The main aim of the investigations is research of the stress-strain state and strength of the inclined sections of reinforced concrete beam elements in conditions of systemic impact of constructive factors and the factor of external influence. To spotlight the problem of cyclic loadings three series of tests were conducted by the author. Firstly, the analysis of the tests showed that especially cyclic alternating loading reduces the bearing capacity of reinforced concrete beams and their crack resistance by 20 % due to the fatigue of concrete and reinforcement. Thus the change of load sign creates serious changes of stress-strain state of reinforced concrete beam elements. Low cycle loads of constant sign effect the behavior of the constructions not so adversely. Secondly, based on the experimental data mathematical models of elements’ strength were obtained. These models allow evaluating the impact of each factor on the output parameter not only separately, but also in interaction with each other. Furthermore, the material spotlighted by the author describes stress-strain state of the investigated elements, cracking mechanism, changes of deflection values, the influence of mode cyclic loading during the tests. Since the data on the subject are useful and important to building practice, the ultimate aim of the tests will be working out for improvement of nonlinear calculation models of span reinforced concrete constructions taking into account the impact of these loads, and also there will be the development of engineering calculation techniques of their strength, crack resistance and deformability.

Stress-Strain State of Reinforced Concrete Overpass under Load

2020 ◽  
Vol 18 (2) ◽  
pp. 68-81
Author(s):  
I. S. Bondar ◽  
M. Ya. Kvashnin ◽  
D. T. Aldekeeva
Keyword(s):  
Reinforced Concrete ◽  
Strain State ◽  
Concrete Beam ◽  
Reinforced Concrete Beam ◽  
Rolling Stock ◽  
Freezing And Thawing ◽  
Stress Strain ◽  
Stress Strain State ◽  
Operational Load ◽  
Calculation Results

Beam spans are the most vulnerable elements of the bridge system, as they are exposed to direct effects of mobile load, environmental and climatic factors (temperature and humidity effects, including freezing and thawing, shrinkage, humidity, etc.). Appearance of defects of the structure is inevitable; the refore civil engineers face a topical problem of strengthening of damaged structures of bridges. The article discusses some results of calculated values and instrumental measurements of stress-strain state (SSS) of reinforced concrete beam span structures of railway overpass under operational load caused by different rolling stock units. The objective of this study is to control stress-strain state of railway overpass for identification and elimination of defects at early stages. The calculation results obtained, carried out by finite-element method (FEM) in the program ABAQUS/Standard correlate well with experimental data. These results can be used for monitoring the state of artificial structures on main lines of JSC NC KTZ.

scholarly journals Simulation of the Stress-Strain State of Eccentrically Compressed and Tensioned Reinforced Concrete Beams

2020 ◽  
Vol 2 (1) ◽  
pp. 207-214
Author(s):  
Vasyl Karpiuk ◽  
Yuliia Somina ◽  
Oksana Maistrenko ◽  
Fedir Karpiuk
Keyword(s):  
Reinforced Concrete ◽  
Cross Sections ◽  
Strain State ◽  
Concrete Beams ◽  
Reinforced Concrete Beams ◽  
Improved Method ◽  
Stress Strain ◽  
Stress Strain State ◽  
Strain Behaviour ◽  
Concrete Elements

AbstractThe paper deals with the working peculiarities of the support zones of reinforced concrete elements subject to bending with due account of the eccentric compression and tension. The authors performed simulation of the stress-strain behaviour of the indicated structures with the aid of “Lira” software which results are shown in the graphical and tabulated form. The performed simulation allowed of tracing the work of the studied sample beams till collapse. Such approach made it possible to single out and generalize the main collapse patterns of the inclined cross-sections of the reinforced concrete elements subject to bending on which basis the authors developed the improved method to calculate their strength (Karpiuk et al., 2019).

Failure Mechanism Of Bending Reinforced Concrete Elements Under The Action Of Transverse Forces

2020 ◽  
Vol 02 (12) ◽  
pp. 36-43
Author(s):  
Mirzaakhmedova Ugiloy Abdukhalimjohnovna ◽  
Keyword(s):  
Reinforced Concrete ◽  
Failure Mechanism ◽  
Strain State ◽  
Stress Strain ◽  
Stress Strain State ◽  
Concrete Elements

The article under discussion reveals the formation and development of inclined sections in bent reinforced concrete elements under the action of transverse forces. It is established that the strength of the bending element depends on the shape of destruction. Criterion of strength in a flat stress-strain state has been used to evaluate the work of the bending element.

scholarly journals Research of the Residual Bearing Capacity and the Work of Damaged Reinforced Concrete Beams’ Inclined Sections

2020 ◽  
Vol 14 (4) ◽  
pp. 466-472
Author(s):  
Zeljko Kos ◽  
Yevhenii Klymenko ◽  
Kostiantyn Polianskyi ◽  
Andjelko Crnoja
Keyword(s):  
Reinforced Concrete ◽  
Bearing Capacity ◽  
Strain State ◽  
Concrete Beams ◽  
Numerical Test ◽  
Neutral Axis ◽  
Reinforced Concrete Beams ◽  
Stress Strain ◽  
Software Complex ◽  
Stress Strain State

The article is devoted to studies about the stress-strain state and the residual bearing capacity of inclined sections of reinforced concrete beams with concrete damages in the compressed zone near support areas. The developed method of calculating the bearing capacity of the inclined sections of damaged beams is described. The numerical test of prototypes was performed in the LIRA-CAD 2017 software complex. A comparison of the results of laboratory tests, a numerical experiment and calculation results by the proposed method is shown. It is stressed that with an increase in the area of damage, the bearing capacity decreases. The nature of the change in the stress-strain state under the presence of damage is described. It is pointed out that in the damaged samples, there is an inclination of the neutral axis in the cross section of the element – it tilts, the neutral axis becomes, almost, parallel to the front of the damage.

scholarly journals Transverse Impact on Rectangular Metal and Reinforced Concrete Beams Taking into Account Bimodularity of the Material

Materials ◽  
2020 ◽  
Vol 13 (7) ◽  
pp. 1579 ◽  
Author(s):  
Alexey Beskopylny ◽  
Besarion Meskhi ◽  
Elena Kadomtseva ◽  
Grigory Strelnikov
Keyword(s):  
Reinforced Concrete ◽  
Strain State ◽  
Concrete Beams ◽  
Reinforced Concrete Beams ◽  
Normal Stresses ◽  
Reinforcing Bars ◽  
Stress Strain ◽  
Stress Strain State ◽  
Tension And Compression ◽  
The Impact

This article is devoted to the stress–strain state (SSS) study of metal and reinforced fiber-reinforced concrete beam under static and shock loading, depending on the bimodularity of the material, the mass of the beam, and the location of the reinforcing bars in zones under tension and compression. It is known that many materials have different tensile and compression properties, but in most cases, this is not taken into account. The calculations were carried out by using load-bearing metal beams made of silumin and steel and reinforced concrete beams under the action of a concentrated force applied in the middle of the span. The impact load is considered as the plastic action of an absolutely rigid body on the elastic system, taking into account the hypothesis of proportionality of the dynamic and static characteristics of the stress–strain state of the body. The dependences of the maximum dynamic normal stresses on the number of locations of reinforcing bars in zones under tension and compression, the bimodularity of the material, and the reduced mass of the beam are obtained. A numerical study of SSS for metal and concrete beams has shown that bimodularity allows the prediction of beam deflections and normal stresses more accurately.

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