scholarly journals Numerical and experimental investigations of steel-concrete beams with thin-walled section

Vestnik MGSU ◽  
2019 ◽  
pp. 22-32
Author(s):  
Farit S. Zamaliev
Keyword(s):  
Experimental Data ◽  
Computer Simulation ◽  
Strain State ◽  
Concrete Beams ◽  
Concrete Structures ◽  
Stress Strain ◽  
Stress Strain State ◽  
Numerical Studies ◽  
Field Samples ◽  
Thin Walled

Introduction. Conducted is to the evaluation of the stress-strain state of the steel-concrete beams with thin-walled section. In recent times, steel-reinforced concrete structures have become widely used in civilian buildings (beams, slabs, columns). Thin-walled section have not found wide application in steel concrete structures, unlike steel structures. Presents the results of numerical studies of beams consisting of concrete, anchors and steel beams. Two investigating of the location of anchors are given. Numerical investigations are presented of steel-concrete beams with thin-walled section based on numerical studies. Testing procedure and test result are given. Results of calculations, comparison of numerical and experimental studies are presented. Materials and methods. For full-scale experiments, steel I-beams with filling of side cavities with concrete were adopted, screws are used as anchor ties, with varied both the lengths and their location (vertically and obliquely). As steel curved C-shaped steel profiles were used steel profiles from the range of the company “Steel Faces”. ANSYS software package was used for computer modeling. A total of 16 steel concrete beams were considered, for which the results of strength and stiffness evaluation were obtained in ANSYS. Results. The data of the stress-strain state of beams on the basis of computer simulation are obtained. The results are used for the production of field samples. Data of computer simulation are compared with the indicators of field experiments. Conclusions. The stress-strain state of steel-concrete structures was studied on the basis of numerical and experimental data. The proposed calculation method gives good convergence with the experimental data. Anchor connections made from self-tapping screws can be used in studies for modeling in steel-concrete beams structures and other anchor devices, ensuring the joint operation of concrete and steel profiles in structures.

Research of the effect of changing the ratio of the content of steel and basalt-plastic reinforcement on the strength indicators of beams with hybrid reinforcement

2021 ◽  
Vol 2021 (23) ◽  
pp. 167-177
Author(s):  
Serhii Stoyanovich ◽  
Keyword(s):  
Strain State ◽  
Concrete Beams ◽  
Concrete Structures ◽  
Stress Strain ◽  
Control Series ◽  
Metallic Composite ◽  
Stress Strain State ◽  
Stage Of Development ◽  
Hybrid Reinforcement ◽  
Composite Reinforcement

Introduction.The current stage of development of the construction industry is associated with the introduction of new materials into practice, compared with the «traditional» (steel, concrete, wood) have certain advantages in the form of improved strength, corrosion resistance, etc. These materials include non-metallic composite reinforcement.Problems Statement. The main disadvantage of non-metallic composite reinforcement (except for carbon fiber reinforcement) is significantly lower modulus of elasticity compared to metal reinforcement. This is the reason for the occurrence of excessive deformations in concrete structures, does not ensure the fulfillment of the requirements for the second group of limiting states. One of the ways to reduce the de-formations of concrete structures, without a significant increase in the percentage of reinforcement of the section, is the use of hybrid reinforcement, when reinforcement is performed simultaneously with metal and composite reinforcement. Currently, there is a very limited amount of experimental data on the stress-strain state of structures with such reinforcement.Purpose. Research of the stress-strain state of structures with hybrid reinforcement, establishing its effectiveness and the optimal ratio of the content of metal and composite reinforcement to achieve sat-isfactory strength and stiffness of a concrete structure.Materials and Methods. The work of beams under load, reinforced with basalt-plastic reinforce-ment, metal reinforcement (control series) and with hybrid reinforcement with metal and basalt-plastic re-inforcement simultaneously was researched. To find out the effect of changes in the content of basalt-plas-tic reinforcement in relation to metal on the performance of beams with hybrid reinforcement, various series of samples of beams with different ratios of basalt-plastic and metal reinforcement.Results. On the basis of the conducted studies, the nature of the work and destruction of concrete beams with hybrid reinforcement was assessed depending on the percentage of metal and basalt-plas-tic reinforcement. The strength indicators of concrete beams with hybrid reinforcement were obtained and analyzed. The test results showed that the strength of beams with hybrid reinforcement increased in comparison with beams of the control series and was at the level of beams reinforced with basalt-plastic reinforcement. At the same time, the deflections and crack width of the beams decreased.Conclusion. The use of hybrid reinforcement makes it possible to increase the bearing capacity of concrete beams, depending on the percentage of reinforcement in the section. The determining factors for the strength of beams with hybrid reinforcement are the strength of the concrete in the compressed zone and the percentage of section reinforcement. The optimal percentage of the ratio of metal and basalt reinforcement in concrete beams with hybrid reinforcement is 60 % / 40 %.Keywords:beams with hybrid reinforcement, basaltoplastic reinforcement, steel reinforcement, strength, deformability.

scholarly journals STUDIES OF THE STRESS-STRAIN STATE OF REINFORCED CONCRETE BEAMS REINFORCED WITH CARBON FIBER

2021 ◽  
Vol 82 (4) ◽  
pp. 101-110
Author(s):  
I.S. Bondar ◽  
◽  
Al Dulaimi Salman Dawood Salman ◽  
D.T. Aldekeyeva ◽  
R.S. Imambaeva ◽  
...  
Keyword(s):  
Reinforced Concrete ◽  
Carbon Fiber ◽  
Strain State ◽  
Concrete Beams ◽  
Field Studies ◽  
Reinforced Concrete Beams ◽  
Stress Strain ◽  
Reinforced Plastics ◽  
Stress Strain State ◽  
Numerical Studies

The article examines field studies of reinforced concrete beams, fracture schemes, and the nature of the formation, development of cracks in reinforced concrete elements. Modeling the stress-strain state of reinforced concrete beams in the ANSYS software and computational complex, comparing the results of field and numerical studies. A method of finite element modeling of beams reinforced with fiber plastics (carbon fiber reinforced plastics) is proposed. A comparison of fracturing schemes obtained as a result of numerical simulation is presented.

scholarly journals The Stress–Strain State of Three-Layer Precast Flexural Concrete Enclosure Structures with the Contact Interlayers

Buildings ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 88
Author(s):  
Vu Dinh Tho ◽  
Elena Anatolyevna Korol ◽  
Nikolai Ivanovich Vatin ◽  
Hoang Minh Duc
Keyword(s):  
Reinforced Concrete ◽  
Strain State ◽  
Crack Formation ◽  
Concrete Beams ◽  
Precast Concrete ◽  
Concrete Structures ◽  
Reinforced Concrete Beams ◽  
Stress Strain ◽  
Stress Strain State ◽  
The Moment

The research object was three-layer reinforced precast concrete enclosure structures. The structures consist of heavy concrete B25 in the external layers and polystyrene concrete B1 in the internal layer. The stress–strain state of precast concrete structures during crack formation was studied by considering the influence of contact interlayers between different types of concretes. Stereoscopic microscopy and scanning electron microscopy were used in the experimental study of multilayer concrete blocks. Samples were made with a varied break time from 30 min to two hours between the previous and the next concrete layer placings. The experimental results showed that the contact interlayer with mutual penetration of aggregates into the adjacent concrete layers is formed in the successive layer-by-layer placing of various concretes. The thickness of the contact interlayer was up to 1 cm. The contact interlayer affects the solidity of the concrete layers’ connection and the structure’s stress–strain state. A model and method for calculating cracking in three-layer reinforced concrete structures with contact interlayers based on analytical and numerical calculations are proposed. Experimental data confirm the proposed calculation method. The results of three-layer reinforced concrete beams calculations show that: (i) the difference of the moment during crack formation in three-layer reinforced concrete beams schemes with and without taking into account the contact interlayer can reach 9.9%; (ii) the moment during crack formation obtained according to the proposed method is greater than that obtained according to the scheme of the cross-section conversion from 7.4% to 9.1%.

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