Model uncertainties in numerical simulations of reinforced concrete structures

2018 ◽  
Vol 19 (6) ◽  
pp. 2004-2016 ◽  
Author(s):  
Vladimir Cervenka ◽  
Jan Cervenka ◽  
Lukas Kadlec
Keyword(s):  
Reinforced Concrete ◽  
Numerical Simulations ◽  
Concrete Structures ◽  
Reinforced Concrete Structures ◽  
Model Uncertainties

scholarly journals Probabilistic Studies on the Shear Strength of Slender Steel Fiber Reinforced Concrete Structures

2020 ◽  
Vol 10 (19) ◽  
pp. 6955
Author(s):  
Oladimeji B. Olalusi ◽  
Panagiotis Spyridis
Keyword(s):  
Reinforced Concrete ◽  
Steel Fiber ◽  
Concrete Structures ◽  
Shear Resistance ◽  
Shear Capacity ◽  
Fiber Reinforced Concrete ◽  
Reinforced Concrete Structures ◽  
Fiber Reinforced ◽  
Steel Fiber Reinforced Concrete ◽  
Model Uncertainties

Shear failure is a brittle and undesirable mode of failure in reinforced concrete structures. Many of the existing shear design equations for steel fiber reinforced concrete (SFRC) beams include significant uncertainty due to the failure in accurately predicting the true shear capacity. Given these, adequate quantification and description of model uncertainties considering the systematic variation in the model prediction and measured shear capacity is crucial for reliability-based investigation. Reliability analysis must account for model uncertainties in order to predict the probability of failure under prescribed limit states. This study focuses on the quantification and description of model uncertainty related to the current shear resistance predictive models for SFRC beams without shear reinforcement. The German (DAfStB) model displayed the lowest bias and dispersion, whereas the fib Model 2010 and the Bernat et al., model displayed the highest bias and dispersion. The inconsistencies observed in the resistance model uncertainties at the variation of shear span to effective depth ratio are a major cause for concern, and differentiation with respect to this parameter is advised. Finally, in line with the EN 1990 semi-probabilistic approach for reliability-based design, the global partial safety factors related to model uncertainties in the shear resistance prediction of SFRC beams are proposed.

Design of precast reinforced concrete structures of frame buildings: a new set of rules

2019 ◽  
pp. 4-9 ◽  
Keyword(s):  
Reinforced Concrete ◽  
Concrete Structures ◽  
Reinforced Concrete Structures ◽  
Building Frames ◽  
Fine Grained ◽  
Rigid Frame ◽  
Floor Slabs ◽  
Frame Buildings ◽  
Spatial System ◽  
Precast Elements

Currently, prefabricated reinforced concrete structures are widely used for the construction of buildings of various functional purposes. In this regard, has been developed SP 356.1325800.2017 "Frame Reinforced Concrete Prefabricated Structures of Multi-Storey Buildings. Design Rules", which establishes requirements for the calculation and design of precast reinforced concrete structures of frame buildings of heavy, fine-grained and lightweight structural concrete for buildings with a height of not more than 75 m. The structure of the set of rules consists of eight sections and one annex. The document reviewed covers the design of multi-story framed beam structural systems, the elements of which are connected in a spatial system with rigid (partially compliant) or hinged joints and concreting of the joints between the surfaces of the abutting precast elements. The classification of structural schemes of building frames, which according to the method of accommodation of horizontal loads are divided into bracing, rigid frame bracing and framework, is presented. The list of structural elements, such as foundations, columns, crossbars, ribbed and hollow floor slabs and coatings, stiffness elements and external enclosing structures is given; detailed instructions for their design are provided. The scope of the developed set of rules includes all natural and climatic zones of the Russian Federation, except seismic areas with 7 or more points, as well as permafrost zones.

Improvement Of Curvilinear Diagrams Of Concrete Deformation

2019 ◽  
pp. 99-104
Keyword(s):  
Reinforced Concrete ◽  
Peak Load ◽  
Experimental Studies ◽  
Concrete Structures ◽  
Deformation Model ◽  
Reinforced Concrete Structures ◽  
Significant Difference ◽  
Deformation Diagrams

Problems when calculating reinforced concrete structures based on the concrete deformation under compression diagram, which is presented both in Russian and foreign regulatory documents on the design of concrete and reinforced concrete structures are considered. The correctness of their compliance for all classes of concrete remains very approximate, especially a significant difference occurs when using Euronorm due to the different shape and sizes of the samples. At present, there are no methodical recommendations for determining the ultimate relative deformations of concrete under axial compression and the construction of curvilinear deformation diagrams, which leads to limited experimental data and, as a result, does not make it possible to enter more detailed ultimate strain values into domestic standards. The results of experimental studies to determine the ultimate relative deformations of concrete under compression for different classes of concrete, which allowed to make analytical dependences for the evaluation of the ultimate relative deformations and description of curvilinear deformation diagrams, are presented. The article discusses various options for using the deformation model to assess the stress-strain state of the structure, it is concluded that it is necessary to use not only the finite values of the ultimate deformations, but also their intermediate values. This requires reliable diagrams "s–e” for all classes of concrete. The difficulties of measuring deformations in concrete subjected to peak load, corresponding to the prismatic strength, as well as main cracks that appeared under conditions of long-term step loading are highlighted. Variants of more accurate measurements are proposed. Development and implementation of the new standard GOST "Concretes. Methods for determination of complete diagrams" on the basis of the developed method for obtaining complete diagrams of concrete deformation under compression for the evaluation of ultimate deformability of concrete under compression are necessary.

SEISMIC ANALYSIS OF MULTISTOREY REINFORCED CONCRETE STRUCTURES

2019 ◽  
Vol 9 (1) ◽  
pp. 61
Author(s):  
SINGH RAVIKANT ◽  
KUMAR SINGH VINAY ◽  
YADAV MAHESH ◽  
◽  
◽  
...  
Keyword(s):  
Reinforced Concrete ◽  
Seismic Analysis ◽  
Concrete Structures ◽  
Reinforced Concrete Structures

Reducing The Life Cycle Cost of Reinforced Concrete Structures by using Fiber in Concrete

2014 ◽  
Vol 4 (3) ◽  
pp. 1-9
Author(s):  
Badrinarayan Rath ◽  
◽  
Shirish Deo ◽  
Gangadhar Ramtekkar ◽  
◽  
...  
Keyword(s):  
Life Cycle ◽  
Reinforced Concrete ◽  
Life Cycle Cost ◽  
Concrete Structures ◽  
Reinforced Concrete Structures
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