scholarly journals Reinforced concrete structures strengthened with CFRP (ACI x FIB) - Recommendations for bending design criteria

2022 ◽  
Vol 15 (2) ◽  
Author(s):  
Igor Del Gaudio Orlando ◽  
Túlio Nogueira Bittencourt ◽  
Leila Cristina Meneghetti
Keyword(s):  
Reinforced Concrete ◽  
Limit State ◽  
Concrete Structures ◽  
Experimental Tests ◽  
Fiber Reinforced Polymers ◽  
Design Criteria ◽  
Ultimate Limit State ◽  
Reinforced Concrete Structures ◽  
Carbon Fiber Reinforced Polymers ◽  
Model Code

abstract: This work deals with the evaluation of the design criteria and security check (Ultimate Limit State - ULS) of the American (ACI-440.2R, 2017) and European (FIB Model Code, 2010) standards of reinforced concrete structures strengthened with Carbon Fiber Reinforced Polymers (CFRP), by the technique of Externally Bonded Reinforcement (EBR). It is intended to evaluate if, for a given database of 64 experimental tests of beams and slabs, the obtained results respect the safety conditions according to the mentioned standards, to increase the efficiency of this reinforcement technique and to lead to the establishment of regulatory design criteria in Brazil. Results show a conservative match among experimental and theoretical values calculated according to the two guidelines and it is concluded that a future regulation in Brazil on this subject should be based on the FIB Model Code.

Prediction of durability of structural concrete in aggressive exposures

2018 ◽  
Author(s):  
Сергей Леонович ◽  
Sergey Leonovich ◽  
Валентин Доркин ◽  
Valentin Dorkin ◽  
Оксана Чернякевич ◽  
...  
Keyword(s):  
Reinforced Concrete ◽  
Service Life ◽  
Building Materials ◽  
Limit State ◽  
Concrete Structures ◽  
Life Cycles ◽  
Reinforced Concrete Structures ◽  
Concrete Durability ◽  
Concrete Carbonation ◽  
Corrosion Of Steel

The monograph is devoted to the prediction of the longevity of reinforced concrete structures, the destruction of which is associated with corrosion of steel reinforcement caused by chloride aggression or concrete carbonation. On the basis of a comprehensive analysis of models for calculating the service life of structures and experimental data, preference is given to the mathematical model Dura Crete. Life cycles for the main degradation processes in concrete and reinforcement, periods of initiation and propagation of corrosion are considered. Particular attention is paid to the influence of environmental factors and the quality of concrete on the kinetics of chloride penetration and movement of the carbonization front. Formulated limit state design reinforced concrete durability in chloride attacks and carbonation. The basic provisions of the method of calculating the durability of reinforced concrete structures, based on the use of the reliability coefficient for the service life. The practical assessment of service life of reinforced concrete elements taking into account stochastic processes in concrete and reinforcement is made. Verification of the model reliability is performed. For all those interested in the issues of building materials and processes occurring in them.

Experimental Study of Concrete Class Influence on Cracks Spacing

2014 ◽  
Vol 600 ◽  
pp. 558-568
Author(s):  
Omar Zorkane ◽  
Farid Chalah ◽  
Lila Chalah-Rezgui ◽  
Abderrahim Bali ◽  
Mohamed Nadib Oudjit
Keyword(s):  
Experimental Study ◽  
Reinforced Concrete ◽  
Phase Ii ◽  
Normal State ◽  
Limit State ◽  
Concrete Structures ◽  
Reinforced Concrete Structures ◽  
Limit States ◽  
Continuous Beams ◽  
Real Size

The aim of this work is to study the cracking of reinforced concrete continuous beams by considering different classes of concrete. It is well known that the design of reinforced concrete structures includes three limit states (limit state of collapse, limit state of strain and limit state of cracking). The cracks in reinforced concrete structures are admitted in the phase II (cracked sections). Thus, the phenomenon of cracks formation can be treated as a normal state only when their openings are limited to avoid a permanent risk of collapse and ensure durability for the civil engineering concrete structures. The importance of this work is described by the tests made on reinforced concrete continuous beams in real size, under concentrated loads increasing from zero up to collapse, where the concrete class influence on the cracks spacing has been studied. As this wasnt theoretically investigated, the used references for an aim comparison were relative to experimentations made by Monnier and Kuczynski on an only one concrete class to the cracks openings and the spacing evaluation analysis The findings of the research reported in this paper show that there is no effect of the concrete class on the cracks spacing.

scholarly journals Foundations for shear wall structures

1980 ◽  
Vol 13 (2) ◽  
pp. 171-181
Author(s):  
J. R. Binney ◽  
T. Paulay
Keyword(s):  
Reinforced Concrete ◽  
Seismic Response ◽  
Concrete Structures ◽  
Shear Wall ◽  
Design Criteria ◽  
Reinforced Concrete Structures ◽  
Type Design ◽  
Wall Structures

After defining design criteria in general for foundations
of earthquake resisting reinforced concrete structures, principles 
are set out which govern the choice of suitable foundation systems
for various types of shear wall structures. The choice of
foundation systems depends on whether the seismic response of the superstructure during the largest expected earthquake is to be elastic or inelastic. For inelastically responding superstructures, preferably the foundation system should be designed to remain elastic. For elastically responding superstructures, suitable foundation systems may be energy dissipating, elastic or of the rocking type. Design criteria for each of these three foundation types are suggested.

Reliability of Existing Concrete Structures Determined with Physical Models - Carbonation Induced Corrosion

2017 ◽  
Vol 259 ◽  
pp. 255-260 ◽  
Author(s):  
Ivan Zambon ◽  
Anja Vidović ◽  
Alfred Strauss
Keyword(s):  
Reinforced Concrete ◽  
Prediction Models ◽  
Limit State ◽  
Concrete Structures ◽  
Structural Condition ◽  
Empirical Models ◽  
Physical Models ◽  
Reinforced Concrete Structures ◽  
Material Parameter Identification ◽  
Reliability Indices

The main goal of transportation infrastructure management is to optimize the use of infrastructure in the most beneficiary way while respecting the predefined requirements. One of the crucial parts in management strategy is the prediction of behaviour of vital transportation elements. Used prediction models should accurately describe the process of degradation and allow forecasting of structural condition by considering environment, usage and maintenance actions. Deterioration models can be divided into mathematical (statistical), physical and empirical models. Statistical models are based on data that describe condition of structure, such as for example condition rating. Physical models describe damage-causing processes and empirical models are experience based. The focus of this paper is to present the physical model of carbonation in assessment of performance of existing reinforced concrete structures in transportation networks. Assessment is done through determining the probability of limit state of depassivation. In order to determine the carbonation without testing, a special attention has to be given to environmental and material parameter identification. Herein, the identification takes into account weather specifics and construction practice in Austria. Finally, the reliability of existing reinforced concrete structures for combination of different exposure classes and material characteristics is analysed. Based on the analysis of reliability, the carbonation nomogram for engineering use is presented, showing the reliability indices β for the service life of 50 years.

scholarly journals Numerical study of the behaviour of loop bar splicing in joints of reinforced concrete structures

2019 ◽  
Vol 12 (1) ◽  
pp. 39-68
Author(s):  
T. D. L.VASCONCELOS ◽  
V. G. HAACH
Keyword(s):  
Reinforced Concrete ◽  
Numerical Study ◽  
Three Dimensional ◽  
Concrete Structures ◽  
Experimental Tests ◽  
Reinforced Concrete Structures ◽  
Reinforced Concrete Structure ◽  
Ideal Situation ◽  
Parametric Analyses ◽  
Concrete Elements

Abstract Sometimes straight bar splicing takes up too much space in a reinforced concrete structure due to the required overlapping length. Therefore, in limited space situations, loop joints may be a good solution, which has been spread in civil construction, although there are very few studies about it. The aim of the present work is to study the loop joint behavior in reinforced concrete structures under tension. Three dimensional numerical simulations are made using the software DIANA®. Firstly, the calibration of the numerical model based on experimental tests of the literature is performed, followed by parametric analyses varying geometric parameters of the concrete elements and reinforcement. The results indicate that arranging the bars as close as possible to a maximum spacing of 60 mm between axes and considering a minimum splice length equal to the bend diameter of the loops may be an ideal situation for the behavior of this type of connection.

scholarly journals Safety Concept for Textile-Reinforced Concrete Structures with Bending Load

2020 ◽  
Vol 10 (20) ◽  
pp. 7328
Author(s):  
Sergej Rempel ◽  
Marcus Ricker ◽  
Josef Hegger
Keyword(s):  
Limit State ◽  
Concrete Structures ◽  
Experimental Tests ◽  
Design Model ◽  
Tensile Failure ◽  
Ultimate Limit State ◽  
Textile Reinforced Concrete ◽  
Safety Requirements ◽  
Bending Load ◽  
Effective Depth

In most countries, for the production and execution of concrete structures with textile reinforcement, building owners must have a general approval (e.g., “abZ” in Germany) or an individual license (e.g., “ZiE” in Germany). Therefore, it is quite common for building authorities to request experimental tests that evaluate the ultimate limit state (ULS) and the serviceability limit state (SLS). However, these experimental tests are detailed, time-consuming and expensive. A practical and simple design model would help to reduce the number of tests needed and would offer structural planners a useful tool. An important aspect is that such design model must fulfil a set of reliability requirements in order to guarantee an adequate safety standard. To this end, probabilistic calculations are required. For the setup of such model, different parameters must be considered, namely the effective depth d and the tensile failure stress of the textile ft for the concrete compressive strength fc. This article presents the probabilistic calculations needed to attain a general safety factor γT that satisfies all the safety requirements for the textile reinforcement of concrete structures with bending load.

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