Method of assessment of stress-strain state of timber-reinforced concrete structure with complex cross section

The work considers a reinforced concrete beam made of bimodule material on an elastic Winkler base. The influence of the number of reinforcing bars located in the stretched zone on the maximum normal stress and the maximum deflection is numerically investigated. The choice of the cross-section dimensions, such as the width and thickness of the flanges, the height of the beam, causes particular difficulties and is limited by the need to determine specific ratios of I-beam sizes. Numerical investigation allows analyzing the influence of the width of the I-beam flange that is in contact with the elastic base on the maximum tensile stresses and maximum deflection. The effect on the stressed-deformed state of the various cross-section forms is carried out in work for an I-beam, a rectangle, and a T-beam. Related to the fact that for many building materials the elastic moduli for tension and compression differ, it became necessary to determine the influence of material heterogeneity on the stress-strain state of the elements of building structures. In particular, the widespread use of reinforced concrete beams as elements of band foundations requires a refinement of the stress-strain state study taking into account the heterogeneity of concrete.

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Investigation of the bearing capacity of reinforced concrete beams strengthened with reinforced concrete ring under load

Budownictwo i Architektura ◽

10.35784/bud-arch.1766 ◽

2014 ◽

Vol 13 (3) ◽

pp. 065-070

Author(s):

Zinoviy Blikharskyy ◽

Dmytro Dubizhanskyy ◽

Roman Khmil

Keyword(s):

Reinforced Concrete ◽

Bearing Capacity ◽

Cross Section ◽

Strain State ◽

Concrete Beams ◽

Reinforced Concrete Beams ◽

Stress Strain ◽

Normal Cross Section ◽

Stress Strain State ◽

Concrete Ring

Bearing capacity of normal cross section of bending concrete elements reinforced with reinforced concrete ring under load was investigated. Experimental researches of 4 sets of beams with the total number of 16 units were carried out. The results of changes of stress-strain state settings depending on the load level, additional reinforcement, influence of limit level load were analyzed. The three characteristic stages of stress-strain state of reinforced concrete beams strengthened with reinforced concrete ring were defined. Results of experimental investigations of bearing capacity of normal cross section of strengthened beams with reinforced concrete ring under load were presented. Enhancing effect was calculated. According to the results of researches of strengthened beams plots of strain of working armature depending on current bending moment were constructed.

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Bending Effect On The Mechanism Of Punching The Support Zone Of The Reinforced Concrete Slab

Promyshlennoe i Grazhdanskoe Stroitel stvo ◽

10.33622/0869-7019.2019.10.20-28 ◽

2019 ◽

pp. 20-28

Keyword(s):

Reinforced Concrete ◽

Bearing Capacity ◽

Strain State ◽

Concrete Slab ◽

Experimental Studies ◽

Reinforced Concrete Structure ◽

Stress Strain ◽

Reinforced Concrete Slab ◽

Stress Strain State ◽

Reinforced Concrete Slabs

The analysis of various regulatory methods for calculating reinforced concrete slabs for punching and comparing with experiment results is made. The tested sample, measuring equipment and test bench are described. Dimensions and materials for the production of the prototype were chosen on the basis of experience in the construction of girderless and capless regular monolithic reinforced concrete frames. The results of experimental studies of a fragment of a slab reinforced concrete structure in order to study the stress-strain state, when implementing the mechanism of punching, are presented. The results of observations obtained during the tests are presented. A comparison of the nature of operation of the tested fragment of the slab with the nature of operation of the full-fledged construction is given. A comparative analysis of the stress-strain state of the tested sample and the results of the calculation of the bearing capacity for punching according to various normative methods is performed. According to the results of the experiment, the main criteria determining the implementation of the punching mechanism are established, and a new method for calculating girderless floors is proposed on the basis of a fundamentally different approach in determining the bearing capacity.

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Elaboration of testing technique of flat slabs on punching shear strength using finite element modeling

MATEC Web of Conferences ◽

10.1051/matecconf/201819602048 ◽

2018 ◽

Vol 196 ◽

pp. 02048

Author(s):

Valery Filatov ◽

Zulfat Galyautdinov ◽

Alexander Suvorov

Keyword(s):

Finite Element ◽

Reinforced Concrete ◽

Cross Section ◽

Strain State ◽

Concrete Slabs ◽

Finite Element Models ◽

Bending Moments ◽

Stress Strain ◽

Stress Strain State ◽

Reinforced Concrete Slabs

The results of researches on finite-element models of stress-strain state of flat reinforced concrete slabs of beamless frame under punching by columns of square and rectangular cross-section are presented. The purpose of the study was to develop a technique for testing samples plates for punching in the presence of bending moments in a column. The results of the study of deflections of reinforced concrete slabs, the distribution of bending moments in the punching zone of the plate under various loading schemes are presented. Variable parameter was the ratio of the sides of the column cross-section. Comparative analysis of studies results on finite element models has made it possible to choose the optimal variant of applying the load to the test samples, depending on the aspect ratio of rectangular section of column. Results of the conducted research will allow simulating the stress-strain state in the punching zone of natural reinforced concrete slabs of monolithic beamless frame during the test of samples.

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DEFORMATION ANALYSIS OF LAYERED REINFORCED CONCRETE - FOAM CONCRETE FLOOR SLABS

Acta Polytechnica ◽

10.14311/ap.2020.60.0324 ◽

2020 ◽

Vol 60 (4) ◽

pp. 324-337

Author(s):

Oksana Lytvyniak

Keyword(s):

Reinforced Concrete ◽

Cross Section ◽

Strain State ◽

Deformation Analysis ◽

Calculated Cross Section ◽

Foam Concrete ◽

Deformation Method ◽

Stress Strain ◽

Stress Strain State ◽

Floor Slabs

This article presents a theoretical study of a stress-strain state of layered reinforced concrete - foam concrete floor slabs (hereinafter called as the LRFCS), with the use of a deformation analysis. Compressive and tensile diagrams of the foam concrete, a tensile diagram of the reinforced concrete and compressive and tensile diagrams of the reinforcement rod are used for the estimation of the stress-strain state of the calculated cross-section of the LRFCS. It should be noted that this article presents the deformation method of loading by the scheme of pure bending for the LRFCS. This deformation method of loading is determined by six shapes of the stress-strain state. These shapes of the stress-strain state are represented by the corresponding distribution diagrams of the relative deformations and the distribution diagrams of internal stresses in the calculated cross-section of the floor slab. Also, this article presents the corresponding equilibrium equations of internal efforts and moments, which act in the calculated cross-section of the floor slab for all shapes of its stress-strain state. Consequently, the mentioned recommendations and mathematical dependencies allow to evaluate the stress-strain state of the LRFCS from its initial loading to its destruction.

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The impact of the reinforcement percentage on the stress-strain state of the bending steel fiber reinforced concrete elements

MATEC Web of Conferences ◽

10.1051/matecconf/201823002001 ◽

2018 ◽

Vol 230 ◽

pp. 02001 ◽

Cited By ~ 4

Author(s):

Oleksandr Andriichuk ◽

Volodymyr Babich ◽

Ivan Yasyuk ◽

Serhii Uzhehov

Keyword(s):

Reinforced Concrete ◽

Crack Resistance ◽

Cross Section ◽

Strain State ◽

Steel Fiber ◽

Fiber Reinforced Concrete ◽

Steel Fiber Reinforced Concrete ◽

Stress Strain ◽

Stress Strain State ◽

Reinforcement Percentage

The use of concrete with traditional reinforcement pose the problem of finding ways to increase the crack resistance, impact strength, frost resistance and other characteristics, which in turn depend on the strength properties of the material. One of the solution is the use of dispersion reinforced concrete steel fiber concrete (with short steel fibers of 30-50mm). The combination of rigid fibers with significant strength reserves and the concrete could increase the crack resistance of the matrix and other strength characteristics. The paper presents the results of theoretical studies of the reinforcement percentage effect on the stress-strain state of the rectangular cross-section elements of steel fiber reinforced concrete (SFRC) in bending from at repeated loads with levels of application η = 0.5 and η = 0.7 . It is found that the limit deformations of the SFRC cross-section in bending is recommended to calculate using a polynomial function, which gives the greatest convergence between the true values and approximations in comparison with the logarithmic and exponential functions.

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Influence of the Cross-Sectional Shape of a Reinforced Bimodular Beam on the Stress-Strain State in a Transverse Impact

Buildings ◽

10.3390/buildings10120248 ◽

2020 ◽

Vol 10 (12) ◽

pp. 248

Author(s):

Alexey Beskopylny ◽

Elena Kadomtseva ◽

Besarion Meskhi ◽

Grigory Strelnikov ◽

Oleg Polushkin

Keyword(s):

Reinforced Concrete ◽

Stress State ◽

Cross Section ◽

Strain State ◽

Transverse Impact ◽

Stress Strain ◽

Cross Sectional ◽

Stress Strain State ◽

The Cross ◽

The Impact

The paper considers the stress-strain state of a reinforced concrete beam, as a bimodular material, under the action of an impact. The behavior of bimodular concretes with different moduli of elasticity in tension and compression has not been studied enough. At the same time, taking into account the bimodularity of concrete makes it possible to design a more economical structure, especially for dynamic load. In this article, the impact is considered as an absolutely plastic impact of an absolutely rigid body on an elastic system. The stress state is investigated for beams of rectangular, T-section and I-sections, and is compared with and without the bimodularity of reinforced concrete. The analysis of the dependence of the stress state on the shape, cross-sectional dimensions, and the location of reinforcing bars in the compressed and tensioned zones was carried out for lightweight concrete (Et < Ec) and for heavy concrete (Et > Ec) under the action of shock load with and without regard to the mass of the beam. The numerical study shows that taking into account the mass of the beam upon impact significantly decreases the magnitude of the normal stresses in both the tensioned and compressed zones. Beams of rectangular cross-section have the highest load-bearing capacity when the cross-section height is equal for both light and heavy concrete. An increase in the size of the flange of the I-beam in the stretched zone leads to a sharp decrease in normal tensile stresses and a slight increase in normal compressive stresses. The proposed engineering method makes it possible to numerically study the effect on the stress-strain state of a beam under the action of a concentrated impact of various geometric characteristics of the cross-section, bimodularity of the material, size, number and location of reinforcement.

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