scholarly journals 2125) Study on Failure of Reinforced Concrete Structures under Combined Stresses : Part 2. Load-Deflection Characteristics of Columns under Combined Stresses due to Constant Axial Force and Repeated Bending Moment and Shear

1965 ◽  
Vol 40 (0) ◽  
pp. 237
Author(s):  
Seiji Kokusho
Keyword(s):  
Reinforced Concrete ◽  
Axial Force ◽  
Concrete Structures ◽  
Bending Moment ◽  
Reinforced Concrete Structures ◽  
Combined Stresses

STIFFNESS OF REINFORCED CONCRETE STRUCTURES UNDER BENDING WITH TRANSVERSE AND LONGITUDINAL FORCES

2021 ◽  
Vol 98 (6) ◽  
pp. 5-19
Author(s):  
VL.I. KOLCHUNOV ◽  
◽  
O.I. AL-HASHIMI ◽  
M.V. PROTCHENKO ◽  
◽  
...  
Keyword(s):  
Reinforced Concrete ◽  
Cross Sections ◽  
Concrete Structures ◽  
Bending Moment ◽  
Reinforced Concrete Structures ◽  
The Matrix ◽  
Local Shear ◽  
The Difference ◽  
Inclined Cracks ◽  
Opening Width

The authors developed a model for single reinforced concrete strips in block wedge and arches between inclined cracks and approximated rectangular cross-sections using small squares in matrix elements. From the analysis of the works of N.I. Karpenko and S.N. Karpenko the "nagel" forces in the longitudinal tensile reinforcement and crack slip , as a function of the opening width and concrete deformations in relation to the cosine of the angle . The experimental " nagel " forces and crack slip dependences for the connection between and in the form of an exponent for the reinforcement deformations and spacing are determined. The forces have been calculated for two to three cross-sections (single composite strips) of reinforced concrete structures. On the bases of accepted hypothesis, a new effect of reinforced concrete and a joint modulus in a strip of composite single local shear zone for the difference of mean relative linear and angular deformations of mutual displacements of concrete (or reinforcement) are developed. The hypothesis allows one to reduce the order of the system of differential equations of Rzhanitsyn and to obtain in each joint the total angular deformations of concrete and the "nagel" effect of reinforcement. The curvature of the composite bars has a relationship from the total bending moment of the bars to the sum of the rigidities. The stiffness physical characteristics of the matrix from the compressed concrete area and the working reinforcement are obtained in a system of equations of equilibrium and deformation, as well as physical equations.

THE INFLUENCE OF BASALT-COMPOSITE PRESTRESSED REINFORCEMENT ON THE OPERATION OF LOW-REINFORCED CONCRETE STRUCTURES WITH INTERBLOCK CONSTRUCTION JOINTS

2020 ◽  
pp. 50-59
Author(s):  
O.D. RUBIN ◽  
◽  
S.E. LISICHKIN ◽  
O.V. ZYUZINA
Keyword(s):  
Reinforced Concrete ◽  
Experimental Studies ◽  
Concrete Structures ◽  
Bending Moment ◽  
Reinforced Concrete Beam ◽  
Hydraulic Structures ◽  
Reinforced Concrete Structures ◽  
Beam Type ◽  
Construction Joints ◽  
Composite Reinforcement

It is proposed to use prestressed basalt composite reinforcement to strengthen reinforced concrete structures of hydraulic structures. In order to substantiate technical reinforcement of reinforced concrete structures of hydraulic structures with prestressed basalt composite inforcement, experimental studies were carried out. For experimental studies, reinforced concrete beam-type structures with vertical interblock construction joints were adopted.The results of experimental studies of reinforced concrete models of beam type with interblock joints reinforced with prestressed basalt composite reinforcement by the method of tension “on concrete”are presented. The models are tested for bending moment and transverse force. A special character of cracking is noted; full restoration of the bearing capacity of reinforced concrete structures, weakened by interblock construction joints, was recorded due to the reinforcement of prestressed basalt composite reinforcement.

A new method for estimating the scale of fluctuation in reliability assessment of reinforced concrete structures considering spatial variability

2018 ◽  
Vol 21 (13) ◽  
pp. 1951-1962 ◽  
Author(s):  
Yiming Yang ◽  
Jianxin Peng ◽  
Jianren Zhang ◽  
CS Cai
Keyword(s):  
Reinforced Concrete ◽  
Spatial Variability ◽  
Bayesian Information Criterion ◽  
Concrete Structures ◽  
Estimation Method ◽  
Bending Moment ◽  
Information Criterion ◽  
Geometrical Parameters ◽  
Reinforced Concrete Structures ◽  
Scale Of Fluctuation

The scale of fluctuation ( θ) of the material and geometrical parameters is the basis of studying the spatial variability of reinforced concrete structures. In this article, a new estimation method for the scale of fluctuation based on Bayesian information criterion is proposed. And based on the analysis of experimental data recorded on the three 36-year-old beams of the Jianggong Bridge and 246 corroded steel bars, the scale of fluctuation ( θ) of concrete compressive strength ( fc) and steel pitting factor ( R) are estimated. The theoretical bending moment of three test beams are calculated considering the influence of the spatial distributions of fc, R, and other relative variables. The reasonableness and superiority of the Bayesian information criterion model than the auto-correlation function method and the semivariogram function model are verified by comparing the theoretical results with the measured bending moment of the three beams mentioned above.

scholarly journals Construction of the interaction curve of concrete-encased composite columns based on the deformation domains of reinforced concrete sections

2015 ◽  
Vol 8 (4) ◽  
pp. 447-466 ◽  
Author(s):  
P. A. S. ROCHA ◽  
K. I. DA SILVA
Keyword(s):  
Reinforced Concrete ◽  
Computer Program ◽  
Axial Force ◽  
Concrete Structures ◽  
Reinforced Concrete Structures ◽  
Longitudinal Reinforcement ◽  
Limit Values ◽  
Composite Columns ◽  
Interaction Curves ◽  
The Moment

AbstractThis paper proposes a methodology for obtaining the interaction curve for composite steel-concrete sections subject to combined compression and bending based on the deformation domains of reinforced concrete structures defined by ABNT NBR 6118 [1]. For this, were developed expressions for the axial force, the moment and the strains of concrete, longitudinal reinforcement and the elements comprising the metal profile in each deformation domain.Based on these expressions a computer program called MDCOMP (2014) was created. In this study the same limit values of longitudinal reinforcement strain defined by ABNT NBR 6118 [1] were used for the steel profile strains. To verify the numerical implementations performed, the interaction curves and the plastic resistance of the section obtained by MDCOMP program were compared with those determined from the recommendations of Eurocode 4 [2], of ABNT NBR 8800 [3] or literature responses.

scholarly journals Influence of the reinforcement corrosion on the bending moment capacity of reinforced concrete beams: a structural reliability approach

2014 ◽  
Vol 7 (3) ◽  
pp. 379-413
Author(s):  
E. A. P. Liberati ◽  
E. D. Leonel ◽  
C. G. Nogueira
Keyword(s):  
Reinforced Concrete ◽  
Structural Reliability ◽  
Concrete Structures ◽  
Bending Moment ◽  
Probability Of Failure ◽  
Reinforced Concrete Beams ◽  
Chloride Diffusion ◽  
Reinforced Concrete Structures ◽  
Moment Capacity ◽  
Major Factors

Reinforced concrete structures are, certainly, one of the most used types of structure around world. When it is located in non-aggressive environments, it respects, in general, the structural life predicted. Unless the structure be used improperly. However, the durability of these structures is strongly connected to degradation processes whose origin is environmental and/or functional. Among these processes, it is worth to mention those related to corrosion of reinforcements. The reinforcement's corrosion is directly related to the durability and safety of concrete structures. Moreover, the chlorides diffusion is recognized as one of major factors that triggers the corrosion. Therefore, at modelling accurately the chloride diffusion, the corrosion of reinforcements can be better evaluated. Consequently, design criteria can be more realistically proposed in order to assure safety and economy into reinforced concrete structures. Due to the inherent randomness present on chloride diffusion and corrosion, these phenomena can only be properly modelled considering probabilistic approaches. In this paper, the durability of a beam designed using the criteria proposed by ABNT NBR 6118:2003 [1] is assessed using probabilistic approaches. The corrosion time initiation is determined using Fick's diffusion law whereas Faraday's corrosion laws are adopted to model the steel loss. The probability of structural failure is determined using Monte Carlo simulation. The mentioned beam is analysed considering different failure scenarios in order to study the influence of water/cement ratio and environmental aggressiveness on the probability of failure. Based on these results, some remarks are performed considering NBR recommendations and the real probability of failure.

scholarly journals Influence of the stiffness of beam-column connections on the structural analysis of reinforced concrete buildings

2018 ◽  
Vol 11 (4) ◽  
pp. 834-855
Author(s):  
J. B. SANTOS ◽  
T. J. DA SILVA ◽  
G. M. S. ALVA
Keyword(s):  
Reinforced Concrete ◽  
Structural Analysis ◽  
Concrete Structures ◽  
Bending Moment ◽  
Analytical Models ◽  
Reinforced Concrete Structures ◽  
Overall Stability ◽  
Partial Transfer ◽  
Structural Calculation ◽  
Real Behavior

Abstract Conventional structural analysis of buildings in reinforced concrete is performed considering beam-column connections as rigid. However, experimental results prove the existence of relative rotations in beam-column connections of reinforced concrete structures, showing the partial transfer of bending moment. In this study the influence of the stiffness of beam-column connections on the global stability and in the column bending moments of buildings in reinforced concrete was investigated. A building was designed with rigid connections and deformable connections to identify the importance of considering the influence of the stiffness of the beam-column connections in the overall stability of monolithic and in the redistribution efforts in reinforced concrete structures. In order to determine the stiffness rotation of deformable connections, two analytical models available in literature were used, and a comparison between the results obtained by each analytical model was also performed. Based on the results, it is concluded that neglecting the influence of the stiffness of the beam-column connections on the analysis of monolithic reinforced concrete structures may result in different solutions compared to the real behavior of the structure. The stiffness values obtained with the analytical models usually differ from the condition of rigid connections, suggesting an adjustment on the standard consideration of rigid connections adopted by the computer programs of structural calculation.

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