scholarly journals Longitudinal-transverse bending of physically nonlinear reinforced concrete beams

2021 ◽  
pp. 85-93
Author(s):  
Юрий Владимирович Немировский ◽  
Сергей Владимирович Тихонов
Keyword(s):  
Reinforced Concrete ◽  
Least Squares ◽  
Concrete Beams ◽  
Least Squares Method ◽  
Reinforced Concrete Beams ◽  
Third Order ◽  
Transverse Bending ◽  
Experimental Deformation ◽  
Tension And Compression ◽  
Deformation Diagrams

В работе рассматриваются экспериментальные диаграммы деформирования бетонов марок B10, B30, B50. Методом наименьших квадратов приведены аппроксимации диаграмм деформирования полиномами второго и третьего порядка. Указанные расчеты выполнены как для случая одинаковых коэффициентов для зон растяжения и сжатия, так и различных. Приведен алгоритм решения задачи продольно-поперечного изгиба балки в случае использованных данных аппроксимаций диаграмм. The paper considers experimental deformation diagrams of concrete grades B10, B30, B50. The approximation of the deformation diagrams by polynomials of the second and third order is given by the least squares method. The calculations were performed both for the case of the same coefficients for the zones of tension and compression, and different ones. An algorithm for solving the problem of longitudinal-transverse bending of a beam in the case of the used data of approximations of diagrams is given.

scholarly journals DETERMINATION OF CRACK RESISTANCE OF PRESTRESSED REINFORCED CONCRETE BEAMS OF TRAPEZOIDAL CROSS-SECTION

2021 ◽  
Vol 6 (11) ◽  
pp. 41-48
Author(s):  
Y. Nikulina
Keyword(s):  
Reinforced Concrete ◽  
Crack Resistance ◽  
Cross Section ◽  
Concrete Beams ◽  
Computer Calculation ◽  
Reinforced Concrete Beams ◽  
Deformation Model ◽  
Resource Saving ◽  
Trapezoidal Cross Section ◽  
Deformation Diagrams

Beams of a trapezoidal cross-section with a wide upper edge with prestressed reinforcement combine positive qualities in terms of strength, crack resistance, deformability and resource saving, which allows them to cover significant spans of multi-storey buildings. To develop a method for calculating the moment of cracking in these structures, a nonlinear deformation model was adopted, which includes equilibrium equations, conditions for the linear distribution of relative deformations along the height of the element section, and refined deformation diagrams of concrete and reinforcement. Concrete state diagrams are assumed to be nonlinear without a falling branch. To describe the deformation diagrams of high-strength and conventional reinforcement, a universal dependence is adopted, consisting of one linear and two nonlinear equations, in which the calculation of individual parameters is performed using different formulas. For the initial stage of the crack formation process, a design scheme is presented, in accordance with which the necessary equations and ratios are drawn up in relation to the considered prestressed reinforced concrete beam of a trapezoidal cross-section. The purpose of the study, in addition to developing a calculation methodology, was also the development of an algorithm and a computer calculation program. To obtain and analyze the results, a numerical experiment was carried out, the results of which are presented in tabular form. Due to the fact that the calculation method was built without involving empirical dependencies, the possibility of its application to determine the crack resistance of prestressed reinforced concrete beams of trapezoidal cross-section for any class of concrete and reinforcement was confirmed.

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.

Flexural Performance of Reinforced Concrete Built-up Beams with SIFCON

2020 ◽  
Vol 38 (5A) ◽  
pp. 669-680
Author(s):  
Ghazwan K. Mohammed ◽  
Kaiss F. Sarsam ◽  
Ikbal N. Gorgis
Keyword(s):  
Reinforced Concrete ◽  
Ultimate Load ◽  
Concrete Beams ◽  
Steel Fibers ◽  
Reinforced Concrete Beams ◽  
Load Carrying Capacity ◽  
Conventional Concrete ◽  
Flexural Performance ◽  
Load Carrying ◽  
Fiber Concrete

The study deals with the effect of using Slurry infiltrated fiber concrete (SIFCON) with the reinforced concrete beams to explore its enhancement to the flexural capacity. The experimental work consists of the casting of six beams, two beams were fully cast by conventional concrete (CC) and SIFCON, as references. While the remaining was made by contributing a layer of SIFCON diverse in-depth and position, towards complete the overall depths of the built-up beam with conventional concrete CC. Also, an investigation was done through the control specimens testing about the mechanical properties of SIFCON. The results showed a stiffer behavior with a significant increase in load-carrying capacity when SIFCON used in tension zones. Otherwise high ductility and energy dissipation appeared when SIFCON placed in compression zones with a slight increment in ultimate load. The high volumetric ratio of steel fibers enabled SIFCON to magnificent tensile properties.

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