scholarly journals Study of the origins and mechanisms responsible for the occurrence of faults in reinforced concrete structures

2021 ◽  
Author(s):  
Laís Porto Miranda ◽  
Davi Vicente Siqueira ◽  
Glauber Soriano Ribeiro ◽  
Adriana Meireles Macedo Abreu ◽  
Zélia Maria Peixoto Chrispim
Keyword(s):  
Reinforced Concrete ◽  
Concrete Structures ◽  
Reinforced Concrete Structures ◽  
Transport Mechanisms ◽  
Reinforced Concrete Structure ◽  
Physical Processes ◽  
Corrective Maintenance ◽  
Useful Life ◽  
Materials Used ◽  
The Relationship

Failures in the planning and execution of a work reduce the useful life of the structure, so bring on excessive expenses with corrective maintenance. The life of a building can be divided into four phases, being: design, execution, preventive maintenance and corrective maintenance. Throughout their useful life, systems and construction elements require maintenance actions to be able to maintain their safe conditions. However, pathologies can originate in the conception stage, execution or use of the structure, the causes being linked to characteristic, superficial factors and physical processes. In this context, it was noticed the need to carry out scientific studies on the behavior of structures and the problems they may cause in them, emerging then to the area of pathology in the context of civil engineering. In this research, look for understand the relationship between the materials used, the transport mechanisms of aggressive agents, the deterioration mechanisms and the environment, with the appearance of pathological symptoms in reinforced concrete structures. For this purpose, will be used a bibliographical study and a survey of the types of pathologies in reinforced concrete structures, the identification of causes, the techniques used to correct problems and the materials recommended for use in repairs. Furthermore, the analysis of some case studies will be adopted, with photographic records of the problems found, where the causes of anomalies will be exposed, and measures that were taken in order to solve the pathologies. It is expected with the results to understand the origins and mechanisms responsible for the occurrence of faults and pathologies in reinforced concrete structure.

Research on Parameters of RC Structure Reliability

2014 ◽  
Vol 501-504 ◽  
pp. 1061-1064
Author(s):  
Bin Cai ◽  
Xin Hui Liu
Keyword(s):  
Reinforced Concrete ◽  
Structural Reliability ◽  
Concrete Structures ◽  
Reinforced Concrete Structures ◽  
Engineering Structures ◽  
Reliability Design ◽  
Structure Reliability ◽  
Rc Structure ◽  
Practical Engineering ◽  
Materials Used

In the analysis of engineering structures are usually adopt the method of fixed value, that is the practical engineering structure under load and the performance of materials used by structure shall be treated as a constant value.But, in fact, the structure of geometry size, bear the load, material parameters,computing model and so on are affected by various factors. In order to more accurately reflect the reliability problems of reinforced concrete structures, this paper, the factors above will be regarded as random variables, combining the basic theory of reliability design, through the probability analysis, in normal uselimit state reliability of reinforced concrete structures for example analysis of the influence of related parameters on the structural reliability.

scholarly journals Modeling Blast Loading on Buried Reinforced Concrete Structures with Zapotec

2008 ◽  
Vol 15 (2) ◽  
pp. 137-146 ◽  
Author(s):  
Greg C. Bessette
Keyword(s):  
Reinforced Concrete ◽  
Concrete Structure ◽  
Explosive Charge ◽  
High Explosive ◽  
Concrete Structures ◽  
Blast Loading ◽  
Reinforced Concrete Structures ◽  
Reinforced Concrete Structure ◽  
Solution Approach ◽  
Coupling Algorithm

A coupled Euler-Lagrange solution approach is used to model the response of a buried reinforced concrete structure subjected to a close-in detonation of a high explosive charge. The coupling algorithm is discussed along with a set of benchmark calculations involving detonations in clay and sand.

Fuzzy uncertainty and its applications in reinforced concrete structures

2020 ◽  
Vol 18 (5) ◽  
pp. 1175-1191
Author(s):  
Utino Worabo Woju ◽  
A.S. Balu
Keyword(s):  
Reinforced Concrete ◽  
Material Properties ◽  
Concrete Structure ◽  
Concrete Structures ◽  
Fuzzy Relation ◽  
Reinforced Concrete Structures ◽  
Reinforced Concrete Structure ◽  
Intermediate Grades ◽  
Content Type ◽  
Degree Of Membership

Purpose The aim of this paper is mainly to handle the fuzzy uncertainties present in structures appropriately. In general, uncertainties of variables are classified as aleatory and epistemic. The different sources of uncertainties in reinforced concrete structures include the randomness, mathematical models, physical models, environmental factors and gross errors. The effects of imprecise data in reinforced concrete structures are studied here by using fuzzy concepts. The aim of this paper is mainly to handle the uncertainties of variables with unclear boundaries. Design/methodology/approach To achieve the intended objective, the reinforced concrete beam subjected to flexure and shear was designed as per Euro Code (EC2). Then, different design parameters such as corrosion parameters, material properties and empirical expressions of time-dependent material properties were identified through a thorough literature review. Findings The fuzziness of variables was identified, and their membership functions were generated by using the heuristic method and drawn by MATLAB R2018a software. In addition to the identification of fuzziness of variables, the study further extended to design optimization of reinforced concrete structure by using fuzzy relation and fuzzy composition. Originality/value In the design codes of the concrete structure, the concrete grades such as C16/20, C20/25, C25/30, C30/37 and so on are provided and being adopted for design in which the intermediate grades are not considered, but using fuzzy concepts the intermediate grades of concrete can be recognized by their respective degree of membership. In the design of reinforced concrete structure using fuzzy relation and composition methods, the optimum design is considered when the degree of membership tends to unity. In addition to design optimization, the level of structural performance evaluation can also be carried out by using fuzzy concepts.

Research on Factors Affecting Durability and Improvements for FRP Reinforced Concrete Structures

2011 ◽  
Vol 189-193 ◽  
pp. 847-852 ◽  
Author(s):  
Lei Tan ◽  
Xi Jun Liu ◽  
Ming Qiao Zhu
Keyword(s):  
Reinforced Concrete ◽  
Concrete Structure ◽  
Civil Engineering ◽  
Concrete Structures ◽  
Reinforced Concrete Structures ◽  
Reinforced Concrete Structure ◽  
Factors Affecting ◽  
Related Research ◽  
Durability Of Concrete ◽  
At Home

With wide applications of FRP in civil engineering, it is necessary to study the durability of FRP reinforced concrete structure. Based on the related research both at home and abroad, the factors affecting durability of FRP reinforced concrete structures and the corresponding improvements have been put forward by analyzing the durability of concrete, FRP materials and reinforced structures, respectively.

scholarly journals Increase of fire resistance of reinforced concrete structures with polypropylene microfiber

2018 ◽  
Vol 245 ◽  
pp. 03005 ◽  
Author(s):  
Marina Gravit ◽  
Elena Golub
Keyword(s):  
Reinforced Concrete ◽  
Fire Resistance ◽  
Concrete Structures ◽  
Point Of View ◽  
Reinforced Concrete Structures ◽  
Fibrous Materials ◽  
Reinforced Concrete Structure ◽  
Explosive Spalling ◽  
High Rise ◽  
Concrete Mix

The increase in the construction of high-rise, technically complex buildings and structures is a prerequisite for the widespread use of structures of heavy concrete. In this work, a special type of destruction of this type of concrete is considered in the fire action explosive spalling. One method of protection is polypropylene microfiber, the objective of which is to increase the fire resistance of concrete and reinforced concrete structures. The fire resistance tests of the reinforced concrete structure with the use of microfiber and without it have been carried out. It is shown that polypropylene microfiber can completely prevent explosive spelling of concrete. In addition, the introduction of additives in the form of fibrous materials into the concrete mix is the most optimal from the point of view of labor intensity and material costs.

Fire Resistance of Non-Crack Resistant Flexural Reinforced Concrete Elements

2015 ◽  
Vol 725-726 ◽  
pp. 15-20
Author(s):  
Vyacheslav Belov ◽  
Valery Morozov
Keyword(s):  
Reinforced Concrete ◽  
High Temperature ◽  
Fire Resistance ◽  
Concrete Structures ◽  
National Income ◽  
Developed Countries ◽  
Reinforced Concrete Structures ◽  
Reinforced Concrete Structure ◽  
Actual Problem ◽  
Concrete Elements

In developed countries only loss of property because of fire makes annually up to 2% of their national income [9, 15]. The bearing capacity of reinforced concrete structures at high temperature impact is lost within several dozens of minutes [1, 3, 5, 10, 12, 18, 25]. Disappointing statistics of increase of both the number of fires and the scope of damage due to them aggravates the actual problem of determination of reinforced concrete structures fire-endurance. The main problems and methods of evaluation of reinforced concrete structure fire resistance are stated. Within the framework of block approach to evaluation of strain of flexural reinforced concrete elements with cracks, design model of reinforced concrete thermo-force resistance is made. Extended nomenclature of influences of high temperature at fire on decrease of performance of bearing reinforced concrete structures is considered. Empirical dependencies of strength and strain characteristics of concrete and reinforcement on high temperatures are used. Proposals on specification of evaluation of fire resistance of statically indeterminate reinforced concrete structures are formulated.

Application of Repair and Anti-Corrosion Technology on Reinforced Concrete Structures of a Domestic Wharf

2011 ◽  
Vol 189-193 ◽  
pp. 165-168
Author(s):  
Xiao Dong Zhao ◽  
Xi Qiu Fan ◽  
Mei Ling Tian
Keyword(s):  
Reinforced Concrete ◽  
Research Work ◽  
Concrete Structures ◽  
Detection Methods ◽  
Reinforced Concrete Structures ◽  
Reinforced Concrete Structure ◽  
The Status ◽  
Multiple Detection ◽  
Technical Discussion ◽  
Technical Basis

According to the status and service environment of a domestic wharf, the corrosion of reinforced concrete structure was evaluated by multiple detection methods, on the base of which the corresponding repair and anti-corrosion program were adopted, thus good preservative effect was achieved. The research work and demonstration project are expected to provide technical discussion and reference for peer experts, as well as technical basis for the corrosion protection of reinforced concrete structures in similar marine environment.

scholarly journals Grounds for the decision to strengthen reinforced concrete structures after short-term impulse loads, using Alluriquin HPP as an example

2019 ◽  
pp. 6-6
Author(s):  
Oleg Rubin ◽  
Anton Antonov ◽  
Sergey Lisichkin ◽  
Kirill Frolov ◽  
Andrey Lisichkin
Keyword(s):  
Reinforced Concrete ◽  
Concrete Structure ◽  
Concrete Structures ◽  
Reinforced Concrete Structures ◽  
Reinforced Concrete Structure ◽  
Floor Slab ◽  
Concrete Floor ◽  
Removal Method ◽  
Load Removal ◽  
Impulse Load

Introduction. Floorings of the turbine hall and installation sites of the HPP (PSS) are one of the most important reinforced concrete structures, as during operation they are subjected to significant process duties, including those not provided for by the project. Thus, during the testing of crane equipment on the floor surface of the installation site of the Alluriquin HPP under construction, the cargo weighing 22 tons fell, under the influence of which the floor slab was punched, which required a comprehensive study of the condition of the reinforced concrete structure of the floor and the surrounding area of the failure of structures, as well as the development of measures to strengthen the damaged structure. Materials and Methods. Visual and instrumental studies of the stress and strain state (SSS) of the reinforced concrete structure of the turbine hall slab and surrounding structures were carried out with the use of optical devices (MPB-3 reading microscope), Schmidt hammer to determine the strength of concrete structures, as well as the “reinforcement load removal” method to determine the actual stresses in the reinforcement of structures. Results. The punching of the reinforced concrete floor of the installation site with vertical displacements of the edges of through cracks up to 12 mm, as well as the system of cracks formed during the fall of cargo was revealed. The actual stresses in the reinforcement are determined by the “reinforcement load removal” method. On the basis of finite element modeling the actual condition of structures during the period of cargo fall and after the removal of the load is obtained. On the basis of the analysis of results of field and design studies the schematic diagram of strengthening of structures by carbon composite materials is developed. Conclusions. The actual SSS of the reinforced concrete floor of the installation site and its support structures during the period of the cargo fall and after the termination of the impulse load is established. The vertical displacement of the edges of the crack of the floor punching was 17.5 mm during the period of the fall of the load and 12 mm after the removal of the impulse load. Crack opening width in reinforced concrete structures in the cargo drop area reached 2 mm. At the moment when the cargo fell on the floor slab, the values of stresses in the reinforcement cage reached 200 MPa; after the impact — 76.2 MPa. With a view of the subsequent safe operation of the reinforced concrete floor and surrounding structures the basic schemes of their strengthening by external reinforcement on the basis of carbon fiber have been developed, which have been proved by calculation.

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