scholarly journals COMPARISON OF THE STRUCTURAL PROPERTIES OF CONCRETE BEAMS WITH COMPOSITE BASALT AND STEEL REINFORCEMENT

2021 ◽  
Author(s):  
Serhiy Sakhno ◽  
◽  
Lyudmyla Yanova ◽  
Olena Pischikova ◽  
◽  
...  
Keyword(s):  
Reinforced Concrete ◽  
Bearing Capacity ◽  
Concrete Beams ◽  
Control Sample ◽  
Steel Reinforcement ◽  
Isotropic Hardening ◽  
Utilization Factor ◽  
Advantages And Disadvantages ◽  
The Cost ◽  
Composite Reinforcement

The subject of the study. The work investigated the deformative, strength, and cost parameters of concrete beams with various reinforcement types. The nature of the behavior under a load of beams reinforced with steel reinforcement and beams with basalt reinforcement of multiple diameters has been studied. A research methodology is the studying of finite element models of the reinforced concrete beam. The Drucker-Prager model was used to simulate concrete behavior. For steel reinforcement, a bilinear isotropic hardening model, a linear orthotropic model was used for composite reinforcement. The goal is to reveal the advantages and disadvantages of using basalt composite reinforcement in reinforced concrete. Conclusion of the study. The paper considers the behavior of four models of reinforced beams. In the first model, a control one, steel reinforcement, is used. In the second, the composite reinforcement diameter is equal to the diameter of the steel one. In the third model, the diameters of the composite reinforcement are taken from the conditions of its similar bearing capacity with the steel one. The fourth model's composite reinforcement diameters have been taken from the requirements of its equal deformation with the steel one. The paper presents a method for calculating the corresponding diameters of reinforcement. The model in which the diameters of the composite reinforcement are taken from the conditions of its equal deformation with the steel reinforcement has the beam's best operation. In this case, the deformations and stresses in concrete practically do not differ from the corresponding stresses in the model with steel reinforcement. However, the utilization factor of the bearing capacity of the reinforcement in this model is deficient, and the cost of reinforcing elements is almost three times the cost of steel rods. The model in which the diameters of composite reinforcement are taken based on its equal bearing capacity with steel reduces the cost of reinforcement almost three times. However, such a beam's deformation and strength properties are significantly worse than in the control sample. The model with composite reinforcement diameters equal to the steel reinforcement diameters has no advantages over the model with steel reinforcement.

scholarly journals Creating Conditions for the Industrial Application of Basalt-Plastic Reinforcement in Manufacturing Precast Concrete Structures

2020 ◽  
Vol 9 (4) ◽  
pp. 143-147
Keyword(s):  
Reinforced Concrete ◽  
Service Life ◽  
Bearing Capacity ◽  
Industrial Application ◽  
Precast Concrete ◽  
Concrete Structures ◽  
Road Construction ◽  
Steel Reinforcement ◽  
Composite Polymer ◽  
Composite Reinforcement

The search for alternative methods of replacing steel reinforcement in load-bearing reinforced concrete structures with composite polymer reinforcement is an urgent scientific and practical task. Composite reinforcement (basalt-plastic, fiberglass) is an economically viable alternative to steel reinforcement; it possesses high tensile strength and chemical resistance, light weight (more than 4 times lighter than the steel ones), low thermal conductivity, radio transparency, dielectric properties. Such properties make it possible to use this type of reinforcement of concrete structures in civil, industrial, and road construction. Only in recent years, the specialists in Uzbekistan have paid special attention to the need for composite polymer reinforcement in construction. This type of reinforcement makes it possible to increase the service life of concrete structures and the building as a whole and to reduce the country's dependence on imports of steel reinforcement. At present the production of basalt-plastic reinforcement is localized in the country – its fiber is made from local basalt. For the possibility of industrial application of composite polymer reinforcement in construction, it is necessary to establish a relationship between a customer, a designer, and a manufacturer. For a customer, the project must be economically profitable, a designer must understand the physical and mechanical properties of the reinforcement and know the regulatory base, and a manufacturer must be interested in producing quality units and assemblies in accordance with the interstate standards, and be sure that the reinforcement produced by him will be in demand. The high deformability of structures caused by the low modulus of elasticity of composite reinforcement does not allow the manufacture of structures that work as bending and eccentrically compressed elements, embedded in reinforced concrete; however, it is noted that such reinforcement can be used in structures for which the requirements for the second group of limiting states are not determinant. The national standards acting in the CIS countries and other states limit the scope of application of composite polymer reinforcement in concrete structures in industrial objects of the economic complex. An analysis of the actual operation of prefabricated road panels, taking into account the low deformation characteristics of basalt-plastic reinforcement, showed the possibility of replacing steel reinforcement with a composite polymer one according to the criterion of uniform strength in terms of design tensile strengths while maintaining the number of working reinforcement bars and their location in reinforcing units. The results of testing the pilot panels of the road surface (prefabricated ones) reinforced with basalt-plastic reinforcement were considered to determine their crack resistance and bearing capacity. The test results of experimental road panels show that the bearing capacity not only decreased but substantially increased. The high corrosion resistance of basalt-plastic reinforcement, when used in road panels, contributes to an increase in the service life of such panels, since the values of crack opening under operational loads are set lower than the permissible limit values. The results of this study show that it is possible to expand the scope of industrial application of basalt-plastic reinforcement in the production of precast concrete structures, for example, for road construction. To do this, it is necessary to create a regulatory framework based on the results of relevant research work.

scholarly journals COMPARATIVE ANALYSIS OF RESEARCH AND CALCULATED VALUES OF BEARING CAPACITY OF REINFORCED CONCRETE AND BASALT CONCRETE BEAMS ACCORDING TO RECOMMENDATIONS OF NATIONAL DESIGN STANDARDS

2020 ◽  
pp. 43-49
Author(s):  
I. Karpiuk ◽  
◽  
V. Karpiuk ◽  
E. Klimenko ◽  
A. Tselikova ◽  
...  
Keyword(s):  
Reinforced Concrete ◽  
Comparative Analysis ◽  
Bearing Capacity ◽  
Concrete Beams ◽  
Concrete Structures ◽  
Design Standards ◽  
Metallic Composite ◽  
Regulatory Documents ◽  
Foreign Countries ◽  
Composite Reinforcement

Abstract. Non-metal composite reinforcement is increasingly being used in modern construction. Composite reinforcement is a great step forward over steel, due to its higher strength and corrosion resistance. An analysis of the use of these fittings was performed, which showed that the United States, Japan and China are leading countries in the use of composite fittings. The more active pace of implementation of composite reinforcement is limited by the fact that composite reinforcement does not have a common method for calculating their bearing capacity. That is why the article discusses regulatory documents on the calculation and design of structures reinforced with composite reinforcement from around the world. The article provides a comparative analysis of the calculations of the bearing capacity of prototypes – beams, reinforced with basalt-plastic reinforcement, according to the available design standards of foreign countries, which were among the first to use non-metallic composite reinforcement for reinforcing span concrete structures. The methods of calculating the bearing capacity of beam elements for concrete and non-metallic composite reinforcement according to regulatory documents are examined in detail. A comparative analysis of the actual bearing capacity of inclined sections of basalt concrete beams and its calculated values calculated according to the recommendations of the existing design standards of foreign countries is carried out. The analysis showed that the actual bearing capacity of the inclined sections of basalt concrete beams and its calculated value showed their unsatisfactory convergence. A common feature of all considered foreign design standards is the underestimation, up to several times, of the bearing capacity of inclined sections of prototypes ‒ beams reinforced with both steel and basalt-plastic reinforcement. It has been established that the methods for calculating the bearing capacity of supporting sections of spans of reinforced concrete and basalt concrete structures, presented in national design standards, are based not on the new general method, but on partially improved methods that were used in previously existing standards.

PROSPECTS OF USING NATURAL BLOCK STONE AS A SUPPORTING BUILDING STRUCTURE

2021 ◽  
pp. 60-67
Author(s):  
Oleh Khomenchuk ◽  
◽  
Nelya Ostafiychuk ◽  
Marina Kolodii ◽  
Galyna Skyba ◽  
...  
Keyword(s):  
Reinforced Concrete ◽  
Concrete Beams ◽  
Reinforced Concrete Beams ◽  
Natural Stone ◽  
Building Structure ◽  
Load Bearing ◽  
Advantages And Disadvantages ◽  
External Reinforcement ◽  
Concrete Production ◽  
The Cost

Purpose. Research of reinforcement methods of natural block stone and possibilities of its application as a load-bearing building structure. Methods. The study used such general logical methods as generalization, analysis and synthesis, analogy, abstraction and modelling. Results. Disadvantages of traditional technology of mining of raw materials for concrete production and the factors that increase the final cost of concrete structures are considered. Advantages and disadvantages of natural block stone in comparison with reinforced concrete building structures on the example of foundation blocks are considered. In order to reduce the cost, improve performance and give the production more flexibility, it is proposed to make such blocks of natural stone blocks with low decorative value. The analysis of known methods of reinforcement of natural stone is made, and the scheme of reinforcement of the block is developed. In order to develop effective reinforcement of such blocks, it is proposed to place the longitudinal reinforcement in the holes drilled in the block before its removal from massif, and fill them with self-expanding cement. Known methods of strengthening the inclined sections of reinforced concrete beams without transverse reinforcement are considered. To strengthen the inclined sections of the natural stone block, it is proposed to use a similar system of external reinforcement of reinforced concrete beams with carbon fiber-based tapes, which are glued with epoxy resins. Scientific novelty. For the first time in the general case, it is proposed to use natural block stone, reinforced with internal and external reinforcement, as a load-bearing structural element of the prefabricated ferro-stone foundation. Practical significance. Preliminary calculation of the minimum allowable distance from the inner wall of the holes for reinforcement rods to the outer surface of the unit without taking into account the inhomogeneities and defects that may occur in the rock, and additional loads during operation of such a unit was made. The obtained result is determined by the pressure of the cement mortar, which expands itself. If this distance is reduced, the whole wall may be destroyed. The issues that need to be solved to substantiate the proposed method of manufacturing foundation blocks, which will use all the benefits of natural stone and reduce the cost of manufacturing foundation blocks, are formulated.

Analisa Pola Kegagalan Balok Beton Menggunakan GFRP Bar Tanpa Selimut Beton

2020 ◽  
Vol 24 (1) ◽  
pp. 11-16
Author(s):  
Saddam - Husein ◽  
Rudy Djamaluddin ◽  
Rita Irmawaty ◽  
Kusnadi Kusnadi
Keyword(s):  
Reinforced Concrete ◽  
Concrete Beams ◽  
Concrete Cover ◽  
Steel Reinforcement ◽  
Fiber Reinforced Polymer ◽  
Mode Analysis ◽  
Flexural Capacity ◽  
Reinforced Polymer ◽  
Glass Fiber Reinforced ◽  
Gfrp Bar

SADDAM HUSEIN. Analisa Pola Kegagalan Balok Beton Menggunakan GFRP Bar Tanpa Selimut Beton (dibimbing oleh Rudi Djamaluddin dan Rita Irmawaty) Struktur beton bertulang yang menggunakan tulangan baja pada daerah korosif, menjadi rawan terhadap kerusakan atau penurunan kekuatannya akibat korosi.Korosi pada tulangan baja merupakan salah satu faktor penyebab menurunnya kekuatan struktur beton bertulang. Salah satu material yang dikembangkan mengatasi korosi adalah penggunaan material tulangan GFRP (Glass Fiber Reinforced Polymer). Penelitian ini bertujuan untuk menganalisa kapasitas lentur dan pola kegagalan balok beton tanpa selimut dengan menggunakan material tulangan GFRP bar.   Desain penelitian merupakan eksperimental laboratorium dengan rekapitulasi sebanyak 6 sampel yang terdiri dari 2 Balok beton menggunakan tulangan baja dengan selimut beton, 2 balok beton menggunakan tulangan GFRP bar dengan selimut beton, 2 balok beton menggunakan GFRP bar tanpa selimut beton. Metode pengujian dilakukan dengan dengan pengujian lentur statik monotonik dan Analisis data menggunakan uji kondisi retak awal dan kondisi ultimit.   Hasil penelitian ini menunjukkan bahwa kapasitas lentur pada balok dengan tulangan GFRP bar lebih besar dibandingkan dengan balok tulangan baja dan mampu meningkatkan kapasitas lentur balok dalam menahan beban sebesar 39.76 %, pola kegagalan beton yang terjadi pada balok tulangan baja mengalami kegagalan lentur tekan ditandai dengan retakan yang terjadi pada sisi tertekan dan membentuk retakan tegak dengan sumbu netral beton yang tertekan, sedangkan pada balok beton tulangan GFRP tanpa selimut mengalami kegagalan keruntuhan tekan geser dengan kondisi tulangan berdeformasi (bi-linear) dengan retak miring dan secara tiba-tiba menjalar menuju sumbu netral beton yang tertekan sehingga terjadilah keruntuhan secara tiba-tiba.     SADDAM HUSEIN.Failure mode analysis of concrete Beams Using GFRP rebar Without concrete cover (supervised by Rudi Djamaluddin and Rita Irmawaty)   Reinforced concrete that uses rebar steel in corrosive areas, are prone to damage or decreased strength due to corrosion. Corrosion in the steel reinforcement is one of the factors that decreasing strength of reinforced concrete. One of the materials developed to overcome corrosion is the use of GFRP (Glass Fiber Reinforced Polymer) reinforcement material. This study aims to analyze the flexural capacity and failure mode of concrete beams without concrete cover using material GFRP bar as reinforcement.   The research design was an experimental laboratory with a recapitulation of 6 samples consisting of 2 beams using steel reinforcement with concrete cover.2 concrete beams using reinforcement GFRP bar with concrete cover, 2 beams using GFRP bars without concrete cover. The  research method uses the monotonic static flexure and analyzing the data using the initial crack condition and ultimate conditions test.   The results of the research indicate the flexural capacity of the beams with GFRP bar reinforcement is higher than steel reinforcement beams and can increase 39.76% of the flexural capacity of the beams in holding loads , the failure mode analysis occurs in steel reinforcing beam experiences compressive failure. Failure was characterized  by cracks that occur on the depressing side and form an upright crack with the neutral axis of the compressed concrete, whereas in GFRP reinforced concrete beams without concrete cover, failure of shear compression with conditions of deformed reinforcement (bi-linear) with sloping cracks and suddenly spread towards the neutral axis of the compressed concrete so that there was a sudden collapse.

Analysis on Deformation of Pre-Splitting Steel Reinforced Concrete Beams Strengthened by Prestressed CFRP

2011 ◽  
Vol 243-249 ◽  
pp. 929-933
Author(s):  
Na Ha ◽  
Lian Guang Wang ◽  
Shen Yuan Fu
Keyword(s):  
Reinforced Concrete ◽  
Bearing Capacity ◽  
Concrete Beams ◽  
Bending Moment ◽  
Reinforced Concrete Beams ◽  
Steel Reinforced Concrete ◽  
Cfrp Sheets ◽  
Deformation Curves ◽  
Prestressed Cfrp Sheets ◽  
Theoretical Results

In order to improve the bearing capacity of SRC which is related with deformation and stiffiness, SRC beams should be strengthened by CFRP. Based on the experiment of six pre-splitting steel reinforced concrete beams strengthened with (Prestressed) CFRP sheets, the deformation of beams are discussed. Load-deformation curves are obtained by the experiment. Considering the influence of intial bending moment on SRC beams, the calculated deformation formulas of SRC beams strengthened by (Prestressed) CFRP are deduced. The results showed that the load-deformation curves of normal and strengthened beams respectively showed three and two linear characteristics. The theoretical results which calculated by the formulas of deformation are well agreement with the experimental results.

Strengthening of Reinforced Concrete Beams by Carbon Fiber Composites

2018 ◽  
Vol 931 ◽  
pp. 379-384
Author(s):  
Yuri V. Ivanov ◽  
Yuri F. Rogatnev ◽  
Igor I. Ushakov
Keyword(s):  
Reinforced Concrete ◽  
Carbon Fiber ◽  
Bearing Capacity ◽  
Concrete Beams ◽  
Reinforced Concrete Beams ◽  
Carbon Fiber Composites ◽  
Limiting State ◽  
Reinforced Plastics ◽  
Reinforced Beams ◽  
The Given

The paper considers the results of the experimental study of the reinforced concrete beams strengthened by carbon fiber reinforced plastics (the CFRP). Eight reinforced concrete beams of the 80x160 mm section and 1500 mm designed span have been manufactured and tested. The influence of the number of the CFRP layers (strengthening power) on bearing capacity and rigidity under the static loading of beams in the thirds of the span has been studied. The results obtained indicate the increase in bearing capacity of the reinforced beams from 24% up to 55% and the increase in rigidity by 45% for the commonly adopted limiting state, i.e. achieving ultimate deformations in concrete of the compressed zone). The paper underlines the need for using anchor devices in the form of U-shaped binders to ensure the efficiency of the given method of strengthening.

scholarly journals RETROFITTING AND DACTILITY OF REINFORCED CONCRETE BEAMS USING AN EXTERNAL REINFORCEMENT METHOD

2019 ◽  
Vol 3 (2) ◽  
pp. 135
Author(s):  
Novita Ike Triyuliani ◽  
Sri Murni Dewi ◽  
Lilya Susanti
Keyword(s):  
Reinforced Concrete ◽  
Ultimate Load ◽  
Concrete Beams ◽  
Concrete Block ◽  
Steel Reinforcement ◽  
Reinforced Concrete Beams ◽  
Building Structures ◽  
Average Increase ◽  
External Reinforcement ◽  
Strength And Ductility

The innovations strengthening building structures are important topics. Failure in structures such as beams and columns due to time, re-functions of a building, even initial design errors that are weak or lack the safety factor of a building structure. External reinforced concrete beams are one of the beams currently being developed. It is a concrete block with reinforcement of steel reinforcement on the outer (external) of the beam. This study aims to determine the index of increasing beam strength and ductility after retrofitting external steel reinforcement, which has the dimension of beams 15 x 15 x 100 cm, repeating 12 pcs, with external reinforcement each 6 pcs 2Ø6 and 3Ø6. The results from this study are an increasing the index of beam flexural strength after retrofit with external steel reinforcement. Meanwhile, beams after retrofit with 2Ø6 external steel have an average increase index of 1.25 and 1.21 while for external steel 3Ø6 are 1.29 and 1.60 respectively. The ductility depends on the value of ultimate load and maximum deflection that occurs, where the ductility value for the comparison of each specimen experiences a reduction in the average ductility value with 2Ø6 external steel which is 37.74% and 70.95% while with 3Ø6 external steel is 61,65% and 60.62%. Berbagai inovasi upaya peningkatan kekuatan struktur bangunan telah menjadi bahasan yang penting. Kegagalan pada struktur seperti balok dan kolom karena umur, alih fungsi suatu bangunan, bahkan kesalahan desain awal yang lemah atau kurang memenuhi faktor keamanan suatu struktur bangunan. Balok beton bertulangan eksternal adalah salah satu balok yang sedang dikembangkan pada saat ini, yaitu balok beton dengan perkuatan tulangan baja di sisi terluar (eksternal). Penelitian ini bertujuan untuk mengetahui indeks peningkatan kekuatan balok dan daktilitas setelah dilakukan perbaikan menggunakan tulangan baja eksternal, dengan dimensi balok 15 × 15 × 100 cm berulang 12 buah, penambahan tulangan baja eksternal masingmasing 6 buah 2Ø6 dan 3Ø6. Hasil yang didapat dari penelitian ini adalah indeks peningkatan kekuatan lentur balok setelah dilakukan perbaikan menggunakan tulangan baja eksternal. Dimana balok setelah dilakukan perbaikan dengan baja eksternal 2Ø6 memiliki indeks peningkatan rata-rata 1,25 dan 1,21 sedangkan untuk baja eksternal 3Ø6 masing-masing 1,29 dan 1,60. Daktilitas tergantung dari nilai beban ultimit dan lendutan maksimum yang terjadi, dimana nilai daktilitas untuk perbandingan tiap benda uji mengalami reduksi nilai daktilitas rata-rata dengan baja eksternal 2Ø6 yaitu sebesar 37,74% dan 70,95% sedangkan dengan baja eksternal 3Ø6 sebesar 61,65% dan 60,62%.

scholarly journals Ultimate Compressive Strains and Reserves of Bearing Capacity of Short RC Columns with Basalt Fiber

2021 ◽  
Vol 11 (16) ◽  
pp. 7634
Author(s):  
Aleksandr V. Shilov ◽  
Alexey N. Beskopylny ◽  
Besarion Meskhi ◽  
Dmitry Mailyan ◽  
Dmitry Shilov ◽  
...  
Keyword(s):  
Reinforced Concrete ◽  
Bearing Capacity ◽  
Basalt Fiber ◽  
Lightweight Aggregate ◽  
Short Fiber ◽  
Hydraulic Press ◽  
Steel Reinforcement ◽  
Fiber Reinforced Concrete ◽  
Material Consumption ◽  
Short Columns

Increasing the bearing capacity of reinforced concrete structures, reducing material consumption, and ensuring quality are critical in modern construction. The article presents an experimental study of the ultimate compressive strains of short fiber basalt reinforced concrete columns and provides recommendations for increasing the bearing capacity using steel reinforcement bars with greater strength. The columns were tested in an upright position using a hydraulic press. Strains were measured with dial indicators and a strain gauge station. It was shown that the addition of 10% coarse basalt fiber increased the ultimate compressibility of concrete on ordinary crushed stone by 19.8%, and expanded clay concrete by 26.1%, which led to the strain hardening of concrete under compression by 9.0% and 12%, respectively. Ultimate compressive strains in fiber-reinforced concrete short columns with combined reinforcement increased 1.42 times in columns on a lightweight aggregate and 1.19 times on heavy aggregate. An increase in the ultimate compressibility of concrete makes it possible to use steel reinforcement with greater strength in compressed elements as the concrete crushing during compression occurs primarily due to the reaching of critical values by tensile stresses in the transverse direction. This makes it possible to manufacture structures with a higher load-bearing capacity and less material consumption. A practical example of the application of the proposed approach is given.

Numerical Modelling and Bearing Capacity of Reinforced Concrete Beams

2013 ◽  
Vol 577-578 ◽  
pp. 281-284 ◽  
Author(s):  
Oldrich Sucharda ◽  
Jiri Brozovsky ◽  
David Mikolášek
Keyword(s):  
Reinforced Concrete ◽  
Numerical Modelling ◽  
Bearing Capacity ◽  
Concrete Beams ◽  
Plastic Material ◽  
Stochastic Modelling ◽  
Latin Hypercube Sampling ◽  
Reinforced Concrete Beams ◽  
Material Models ◽  
Plastic Model

This paper discusses the fracture-plastic material models for reinforced concrete and use of this model for modelling of reinforced concrete beams. Load-displacement relations and bearing capacity of reinforced concrete beams will be evaluated. A series of original (own) experiments - the beam and data from completed experiments - have been chosen for the numerical modelling. In case of the original experiments - reinforced concrete beams, stochastic modelling based on LHS (Latin Hypercube Sampling) will be carried out in order to estimate the total bearing capacity. The software used for the fracture-plastic model for reinforced concrete is ATENA.

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