scholarly journals A variety of designs construction and mounting

2019 ◽  
Vol 135 ◽  
pp. 02022
Author(s):  
Tamara Danchenko ◽  
Anatoly Lastovka ◽  
Sergey Amelchugov ◽  
Nadezhda Klinduh ◽  
Maria Berseneva
Keyword(s):  
Reinforced Concrete ◽  
Concrete Structures ◽  
High Strength ◽  
Climatic Conditions ◽  
Reinforced Concrete Structures ◽  
Building Structures ◽  
Metal Structures ◽  
Advantages And Disadvantages ◽  
Building Designs ◽  
Wooden Structures

Abstract in the article the main types of building structures are considered, which are distinguished by the type of material. For the purpose of studying, each type has brief information including its advantages and disadvantages in comparison with others. In the section reinforced concrete structures, the authors characterize this material from three sides - this is the method of manufacture, the type of concrete and its stressed state. As a result, it was found that when choosing a foundation, special attention is paid to: bearing capacity, type of building being built, soil characteristics. In addition to the above, it can be added that weight reduction, cost reduction and material consumption in reinforced concrete structures are possible through the use of high-strength concrete and reinforcement. Metal structures are the most popular building material. The possibilities of this material are very diverse: building designs, designs specifically for certain seismic and climatic conditions, and high decorative properties. Due to its strength and rigidity, buildings can withstand hurricane gusts of wind and earthquakes. In the manufacture of structures in the factory and during installation, steel is subjected to various technological operations: welding, cutting, machining. It was found that in this case the steel does not collapse, it retains the microstructure and mechanical properties. Finally, steel should not have a significant cost of manufacturing structures from it. Turning to the section of wooden structures, the authors list the main advantages - it is comfortable and environmentally friendly and material.

scholarly journals Corrosion protection of reinforcing steel reinforced concrete structures of transport structures

2020 ◽  
Vol 7 (1) ◽  
Author(s):  
Alexander Bulkov ◽  
Michail Baev ◽  
Igor Ovchinnikov
Keyword(s):  
Reinforced Concrete ◽  
Corrosion Protection ◽  
Concrete Structures ◽  
Steel Corrosion ◽  
High Strength ◽  
Curing Temperature ◽  
Reinforced Concrete Structures ◽  
Reinforcing Steel ◽  
Steel Reinforced Concrete ◽  
Advantages And Disadvantages

The influence of reinforcing steel corrosion on the durability of reinforced concrete structures of transport structures and the degree of knowledge of this problem is considered. It is specified that the protection of reinforcing steel from corrosion is not able to completely replace the correct design and use of high-strength concrete. But it is able to extend the life of reinforced concrete structures. It is noted that corrosion of the reinforcement leads to a decrease in the structural strength due to wear and tear and by a third of the period of operation of reinforced concrete structures, as a result of which transport structures collapse. As an example of the detrimental effect of corrosion of reinforcing steel on the durability of transport structures, examples of accidents of bridges and overpasses caused by this type of corrosion are given. As a result, a conclusion is drawn on the advisability of ensuring a sufficient level of corrosion protection of reinforcing steel to achieve the required durability of reinforced concrete structures of transport structures. The types and causes of corrosion processes in reinforcing steel reinforced concrete structures are described. The compositions and technologies of anticorrosive protection are examined and analyzed. Comparison of the compositions of anticorrosive protection of reinforced concrete structures is carried out according to the following criteria: consumption, density, viability, curing temperature and the number of components of the composition. A comparison of anti-corrosion protection technologies is carried out on the basis of the following indicators: line dimensions, productivity and consumption of energy resources. A comparison is also made of the cost of using various anti-corrosion protection technologies. Based on the data obtained, the advantages and disadvantages of the considered compositions and technologies of corrosion protection are determined. As a result, the most effective and technologically advanced method of corrosion protection of steel reinforcement of reinforced concrete structures of transport structures is selected.

scholarly journals Directions of Convergence of the Requirements of the Main Domestic Standard for the Design of Concrete and Reinforced Concrete Structures SP 63.13330.2012 with the Requirements of the International Standard ISO 19338

2019 ◽  
pp. 93-98
Author(s):  
Sergey B. Krylov ◽  
Ravil S. Sharipov ◽  
Sergey A. Zenin ◽  
Yury S. Volkov
Keyword(s):  
Reinforced Concrete ◽  
Prestressed Concrete ◽  
Concrete Structures ◽  
National Standards ◽  
Reinforced Concrete Structures ◽  
Building Structures ◽  
Design Standards ◽  
Structural Concrete ◽  
International Standard ◽  
Assessment Requirements

Design standards on building structures should contain, first of all, the performance and assessment requirements of structures. At the same time, design standards should provide the possibility for design and construction of concrete and reinforced concrete parts of buildings and structures that meet the requirements of the Technical regulations "On the safety of buildings and structures". Taking into account the importance of ensuring the reliability and safety of buildings and structures erected with the use of structural concrete, the technical Committee of the international organization for standardization ISO TC 71 "Concrete, reinforced concrete and prestressed concrete", certifies national standards for compliance with the requirements of the international standard ISO 19338 "Performance and Assessment Requirements for Design Standards on Structural Concrete", developed by the same Committee. The standard describes the issues that should be included in the standards for the design of concrete and reinforced concrete structures (terms and definitions, basic requirements, performance requirements,loads and impacts, design estimates, requirements for manufacturing and construction, as well as quality control). These requirements are common to all standards in the design of concrete and reinforced concrete structures. In this regard, it is relevant and important to establish the possibility of presenting the National Code of rules SP 63.13330.2012 "SNiP 52.01-2003 Plain and Reinforced Concrete Structures. General Provisions" for certification for compliance with the requirements of ISO 19338. To achieve this goal, the relevant work has been done, based on the results of which were made the proposals for the submission of SP 63.13330.2012 for certification for compliance with ISO 19338:2014. These proposals are set out in the text of the article.

scholarly journals Сomparative analysis of the methods of strengthening of masonry, metal structures, reinforced concrete, such as traditional methods and the alternative methods of strengthening by FRP-materials

2020 ◽  
pp. 267-291
Author(s):  
Iryna Rudnieva
Keyword(s):  
Reinforced Concrete ◽  
Bearing Capacity ◽  
Alternative Methods ◽  
Building Structures ◽  
Traditional Methods ◽  
External Appearance ◽  
Metal Structures ◽  
Advantages And Disadvantages ◽  
Heritage Buildings ◽  
Determining Factor

Built mostly centuries ago, heritage buildings as well the more contemporary buildings of the last century, which have lost the bearing capacity often need restoration and strengthening, especially in seismic regions and in regions with shrinkage phenomena (subsidence region). The need of strengthening of the building constructions during exploitation appears mostly because of their premature wear as a result of technological influences and weathering, various damage and various other factors. Traditional methods of strengthening are effective, but in some cases not appropriate or not applicable  for use. An example is the increase of the load-bearing structures of historical buildings, preserving the external appearance of which is the determining factor. In this case, the use of the discussed alternative methods can be justified alternative. Knowledge of the causes of defects and damage of structures allows to choose the best option of repairing or strengthening. The aim of the research is the evaluation of the structural performance of composite fibre-reinforced elements in the wider sector of the conservation of historical, architectonic and environmental heritage, as well the more contemporary buildings of the last century, which have lost of the bearing capacity focusing reliability indexes and the appearance of the structure. In the article was described and analyzed the existing traditional methods and the alternative methods of strengthening by FRP-materials (composite materials) such building structures as masonry, metal structures, reinforced concrete, and the computation in software ABAQUS. These procedures of strengthening building structures by FRP-materials  in Ukraine are not widely used due to the lack of a regulatory framework that would regulate their use, as well because these materials are relatively expensive compared to the traditional ones. The article analyzed the existing methods of computation and design of the strengthening using FRP-materials, and the computation in software ABAQUS was performed with conclusions and recommendations based on results of the computation. The aim of the work was to review the technology and analyze the advantages and disadvantages of each of the strengthen methods that should be used when choosing effective solutions for strengthening building structures. In conclusion, the need for further study and researches was confirmed.

How does concrete strength affect the fire resistance?

2020 ◽  
Vol 11 (3) ◽  
pp. 311-324
Author(s):  
Eva Lubloy
Keyword(s):  
Reinforced Concrete ◽  
Fire Resistance ◽  
Fire Safety ◽  
Strength Class ◽  
Concrete Strength ◽  
Concrete Structures ◽  
Reinforced Concrete Structures ◽  
Building Structures ◽  
Content Type ◽  
Upper Limit

Purpose The aim of the research was to investigate the effect of concrete strength on the fire resistance of structures. At first, it may seem contradictory that higher concrete strengths can decrease the fire resistance of building structures. However, if the strength of the concrete exceeds a maximum value, the risk of spalling (the detachment of the concrete surface) significantly. Design/methodology/approach Prefabricated structural elements are often produced with higher strength. The higher concrete strengths generally do not cause a reduction in the load bearing capacity, but it can have serious consequences in case of structural fire design. Results of two prefabricated elements, namely, one slab (TT shaped panel) and one single layer wall panel, were examined. Results of the specimen with the originally designed composition and a specimen with modified concrete composition were examined, were polymer fibres were added to prevent spalling. Findings As a result of the experiments, more strict regulations in the standards the author is suggested including more strict regulations in the standards. It has been proved that to ensure the fire safety of the reinforced concrete structures, it is required after polymer fibres even in lower concrete strength class than prescribed by the standard. In addition, during the classification and evaluation of structures, it is advisable to introduce an upper limit of allowed concrete strength for fire safety reasons. Originality/value As a result of the experiments, the author suggests including more strict regulations in the standards. It has been proved that to ensure the fire safety of the reinforced concrete structures, it is necessary to require the addition of polymer fibres even in lower concrete strength class than prescribed by the standard. In addition, during the classification and evaluation of structures, it is advisable to introduce an upper limit of allowed concrete strength for fire safety reasons.

scholarly journals The Mechanical Properties of Centrifuged Concrete in Reinforced Concrete Structures

2020 ◽  
Vol 10 (10) ◽  
pp. 3570
Author(s):  
Romualdas Kliukas ◽  
Ona Lukoševičienė ◽  
Arūnas Jaras ◽  
Bronius Jonaitis
Keyword(s):  
Mechanical Properties ◽  
Reinforced Concrete ◽  
Concrete Strength ◽  
Concrete Structures ◽  
High Strength ◽  
Reinforcement Ratio ◽  
Transverse Reinforcement ◽  
Reinforced Concrete Structures ◽  
Test Results ◽  
Moduli Of Elasticity

This article explores the influence of transverse reinforcement (spiral) and high-strength longitudinal reinforcements on the physical-mechanical properties of centrifuged annular cross-section elements of concrete. The test results of almost 200 reinforced, and over 100 control elements are summarizing in this article. The longitudinal reinforcement ratio of samples produced in the laboratory and factory varied from 1.0% to 6.0%; the transverse reinforcement ratio varied from 0.25% to 1.25%; the pitch of spirals varied from 100 mm to 40 mm and the concrete strength varied from 25 MPa to 60 MPa. Experimental relationships of coefficients for concrete strength, moduli of elasticity and limits of the longitudinal strain of centrifuged concrete in reinforced concrete structures in short-term concentrically compression were proposed.

INFLUENCE OF CONCRETE COMPOSITION ON THE CORROSIVE STATE OF THE STEEL ARMATURES AND DURABILITY OF REINFORCED CONCRETE STRUCTURES

2019 ◽  
pp. 33-39
Author(s):  
Petro Koval ◽  
Vladimir Zelenovskiy
Keyword(s):  
Reinforced Concrete ◽  
Concrete Structures ◽  
The State ◽  
Test Method ◽  
Design Stage ◽  
Reinforced Concrete Structures ◽  
Building Structures ◽  
Reinforcing Steel ◽  
Concrete Composition ◽  
Corrosion State

The influence of the composition of the concrete mixture on the state of reinforcing steel as the main problem of corrosion of reinforced concrete structures is considered. The main attention is paid to the need for individual and mandatory consideration of the influence of the properties of additives to concrete on the passivation of reinforcing steel. The purpose of conducting studies to determine the effect of concrete composition on the state of reinforcing steel is to analyze the causes of corrosion of reinforcement, determine the influence of the environment, apply appropriate prevention of this phenomenon and use methods to determine the corrosion state at the design stage of building structures for which reinforced concrete is used. The composition of concrete, in addition to the standard set in various quantitative combinations (cement, gravel, sand, water) today it is advisable to use special additives. Due to their correct and proportional application, you can create a mixture with significantly improved characteristics: with increased frost resistance, strength, durability, with accelerated or delayed setting of the mixture, etc. Nevertheless, you should not forget that the individuality of the composition of additives could affect the ability of concrete to passivate reinforcing steel. It is possible to eliminate the possibility of reducing the passivation of concrete by testing reinforced concrete samples for its protective properties in relation to the reinforcement. The test method is based on the passivation of reinforcing steel in an alkaline environment and consists in evaluating the protective effect of a sample of concrete in relation to a sample of steel reinforcement by comparing data obtained with a change in potential depending on changes in the density of electric current passing through the sample. The issue of quality and durability of reinforced concrete structures, both technically and economically, is attracting increasing attention of builders. It is obvious that in most cases an increase in the initial cost of manufacturing the structure and its reliable protection is economically justified, if this allows reducing the number and cost of repairs during operation. Keywords: reinforcement, corrosion, concrete, reinforced concrete, concrete additive, concrete composition, corrosion state of reinforcement, durability of reinforced concrete structures.

Increase of Temperature and Fire Resistance for Reinforced-Concrete Structures by Surface Treatment with Protective Coating

2018 ◽  
Vol 788 ◽  
pp. 36-44
Author(s):  
Liudmyla Demydchuk ◽  
Dmytro Sapozhnyk
Keyword(s):  
Reinforced Concrete ◽  
Fire Resistance ◽  
Protective Coating ◽  
Concrete Structures ◽  
Fire Retardant ◽  
Reinforced Concrete Structures ◽  
Building Structures ◽  
Fire Tests ◽  
Normative Documents ◽  
Concrete Building

The normative documents of Ukraine (DBN V.1.1.7 ̶ 2016) [1] establish that the limit of fire resistance of reinforced-concrete building structures is determined by the calculation method or by fire tests, and shall be at least 45 minutes. Taking into account the modern construction technologies, namely, the reduction of the section of the main building reinforced-concrete structures, it is expedient to use fire-retardant coatings to provide the necessary fire resistance limit.

scholarly journals Response Modification Factors for Reinforced Concrete Structures Equipped with Viscous Damper Devices

2017 ◽  
Author(s):  
Heshmatollah Abdi ◽  
Farzad Hejazi ◽  
Mohd Saleh Jaafar ◽  
Izian Binti Abd Karim
Keyword(s):  
Reinforced Concrete ◽  
Seismic Design ◽  
Concrete Structures ◽  
Design Parameters ◽  
Reinforced Concrete Structures ◽  
Building Structures ◽  
Viscous Damper ◽  
Response Modification Factor ◽  
Finite Element Software ◽  
Modification Factor

The response modification factor is one of the seismic design parameters that determine the nonlinear performance of building structures during strong earthquakes. Most seismic design codes lead to reduced loads. Nevertheless, an extensive review of related literature indicates that the effect of viscous dampers on the response modification factor is no longer considered. In this study, the effect of implementing viscous damper devices in reinforced concrete structures on the response modification factor was investigated. Reinforced concrete structures with different stories were considered to evaluate the values of the response modification factors. A nonlinear statistic analysis was performed with finite element software. The values of the response modification factors were evaluated and formulated on the basis of three factors: strength, ductility, and redundancy. Results revealed that the response modification factors for reinforced concrete structures equipped with viscous damper devices are higher than those for structures without viscous damper devices. The number of damper devices and the height of buildings have significant effects on response modification factors. In view of the analytical results across different cases, we proposed an equation according to the values of damping coefficients to determine the response modification factors for reinforced concrete structures furnished with viscous damper devices.

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