scholarly journals Effects of Tension Reinforcement Ratio on Ductility of Mid-Rise Reinforced Concrete Structures

2018 ◽  
Vol 1 (1) ◽  
pp. 702-708
Author(s):  
Onur Onat ◽  
Burak Yön

Failure mode of reinforced concrete (RC) structures are classified according to tension reinforcement ratio of beam elements. To determine effect of tension reinforcement ratio on performance of RC structure, two planar RC structure were selected. One of them is 5 stories other of them is 7 stories. Two different concrete class, C20 and C25, were considered for analysis. Three tension reinforcement combinations were considered, three different tension reinforcement ratios were used. First case is the ratio of the tension reinforcement is lower than that of the compression reinforcement, second case is the ratio of the tension reinforcement is equal to the ratio of the compression reinforcement and third case is the ratio of the tensile reinforcement is higher than the compression reinforcement.

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Sanjeev Kumar Verma ◽  
Sudhir Singh Bhadauria ◽  
Saleem Akhtar

Degradation of performance and deterioration of different components of reinforced concrete (RC) structures increase with the age of structure. This deterioration of reinforced component depends on several parameters. However, modeling service life of RC structure by considering all the parameters is a difficult job, as most of the parameters are uncertain in nature. Probabilistic models account well for the uncertainties in the parameters responsible for deterioration of RC structures. This paper presents a review of several recent service life models developed using probability based concepts.


2015 ◽  
Vol 1111 ◽  
pp. 187-192
Author(s):  
Corina Sosdean ◽  
Liviu Marsavina ◽  
Geert de Schutter

Reinforced concrete (RC) became one of the most widely used modern building materials. In the last decades a great interest has been shown in studying reinforcement corrosion as it became one of the main factors of degradation and loss of structural integrity of RC structures. The degradation process is accelerated in the case of RC structures situated in aggressive environments like marine environments or subjected to de-icing salts. In this paper it is shown how steel corrosion of the embedded rebars occurs and how this affects the service life of reinforced concrete structures. Also, an experimental study regarding the combined effect of carbonation and chloride ingress was realized. Samples with and without rebars were drilled from a RC slab which was stored in the laboratory for two years. Non-steady state migration tests were realized in order to determine the chloride profile, while the carbonation depth was measured using the colorimetric method based on phenolphthalein spraying. It was concluded that carbonation has a significant effect on chloride ingress, increasing it.


2014 ◽  
Vol 501-504 ◽  
pp. 1061-1064
Author(s):  
Bin Cai ◽  
Xin Hui Liu

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.


2021 ◽  
Author(s):  
Mahmut Acarcan

Restraint temperature and shrinkage strains are one of the major reasons for cracking of reinforced concrete. Cracking of concrete reduces structural integrity, initiates or accelerates deterioration mechanisms, causes serviceability problems and may raise aesthetical concerns. Particularly for liquid retaining structures, cracks are vital for structural functionality. Measures must be take to prevent or control crack. In most cases, it may not be feasible to prevent crack formation, but crack width can be controlled by providing sufficient amount of reinforcement. Design guides provide limited information on adequate reinforcement design for temperature and shrinkage cracks in reinforced concrete structures. The Finite Element Method(FEM) was used in order to investigate the crack risk, magnitude of crack width, and adequate reinforcement ratio for controlling cracks within the design specifications. In order to find the thermal and shrinkage strains effect during early ages, computer simulations was performed for hardening concrete. Using the computer program ABAQUS/6.4, incremental numerical analysis technique was implemented that provided realistic simulation of stress/strain history. Considering an appropriate value for thermal and shrinkage strains, a parametric study was carried out to estimate the reinforcement ratio for fixed base walls. The crack width was estimated based on the calculated steel stress and the ACI 318-02 crack prediction equation. With consideration of ACI 350-01 specification for allowable crack width, the required amount of reinforcement ratio for various wall dimensions was recommended.


2020 ◽  
Vol 10 (10) ◽  
pp. 3570
Author(s):  
Romualdas Kliukas ◽  
Ona Lukoševičienė ◽  
Arūnas Jaras ◽  
Bronius Jonaitis

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.


Author(s):  
Nour Eldeen Abo Nassar

Reinforced concrete (RC) structures have the ability to be extremely durable and able to withstand a diversity of different environmental cases. However, failure in these structures still happens due to precocious reinforcement erosion. If steel reinforcement corrodes in concrete structures, this leads to a decrease in the lifetime and durability of these structures, which cause early failure of the structures, costing significantly to inspect and maintain the deteriorating structures. Then, monitoring of reinforcement corrosion is of great importance to prevent early failure of structures. Structures corrosion can be decreased through correct monitoring and taking appropriate control measures in the appropriate period of time. When steel bars corrode, the formation of rust causes the concrete to be separated from the steel and then thereafter. In case this issue is not addressed, it may influence the entire structure. This paper attempts to present a comprehensive review of corrosion of rebar in RC structures, its mechanisms, monitoring and prevention.


Sensors ◽  
2020 ◽  
Vol 20 (23) ◽  
pp. 6825
Author(s):  
Woubishet Zewdu Taffese ◽  
Ethiopia Nigussie

In this work, technological feasibility of autonomous corrosion assessment of reinforced concrete structures is studied. Corrosion of reinforcement bars (rebar), induced by carbonation or chloride penetration, is one of the leading causes for deterioration of concrete structures throughout the globe. Continuous nondestructive in-service monitoring of carbonation through pH and chloride ion (Cl−) concentration in concrete is indispensable for early detection of corrosion and making appropriate decisions, which ultimately make the lifecycle management of RC structures optimal from resources and safety perspectives. Critical state-of-the-art review of pH and Cl− sensors revealed that the majority of the sensors have high sensitivity, reliability, and stability in concrete environment, though the experiments were carried out for relatively short periods. Among the reviewed works, only three attempted to monitor Cl− wirelessly, albeit over a very short range. As part of the feasibility study, this work recommends the use of internet of things (IoT) and machine learning for autonomous corrosion condition assessment of RC structures.


2008 ◽  
Vol 385-387 ◽  
pp. 665-668
Author(s):  
Man Hae Han ◽  
Han Seung Lee

Cathodic Protection Method was introduced as a corrosion protection method of metals under the ground or sea. Since 1970, it was applied to corrosion protection method of reinforced concrete structures. After 1990, this method has been used around the world, and its usability was proved. But this method has some problems on the aspect of construction and economy. In order to solve these problems, Cathodic Protection Method by using high durable metal spray was developed. First, the specimen was covered with anodic materials (Zn, Al) by using metal spray. And a performance of corrosion protection was confirmed by measuring corrosion current and halfcell potential of specimen. Through the result of experiment, it is possible to know that Cathodic Protection Method by using high metal spray is good protect to corrosion on reinforced concrete structures.


2021 ◽  
Vol 3 (5) ◽  
Author(s):  
Florin Pavel

AbstractThis case study focuses on the evaluation of the collapse rates of various types of reinforced concrete structures (residential and industrial) as observed from the data collected in Romania after the Mw 7.4 Vrancea earthquake of March 4, 1977. The results of the analyses show that the largest collapse rates were attributed to elevated reinforced concrete silos and water tanks. Moreover, the majority of the collapsed elevated reinforced concrete water tanks were full at the moment of the seismic event. Very small collapse rates were observed for high-rise residential RC structures and for the multi-storey industrial RC structures.


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