scholarly journals Regulatory support for the use of composite rod reinforcement in concrete structures

2020 ◽  
Vol 896 ◽  
pp. 012022
Author(s):  
S Merkulov ◽  
V Rimshin ◽  
E Akimov ◽  
V Kurbatov ◽  
S Roschina
Keyword(s):  
Concrete Structures ◽  
Composite Rod

Fire Resistance Of Concrete Structures With Composite Rod Reinforcement

2019 ◽  
pp. 50-55 ◽  
Keyword(s):  
Bearing Capacity ◽  
Fire Resistance ◽  
Concrete Structures ◽  
Protective Layer ◽  
Maximum Temperature ◽  
Regulatory Requirements ◽  
Composite Rod ◽  
The Moment ◽  
Normative Value ◽  
Composite Reinforcement

The use of composite rod reinforcement makes it possible to ensure the durability of reinforced concrete structures, operated under aggressive conditions. The use of composite reinforcement in concrete structures requires solving the problem of fire resistance of this class of structures. The fire resistance of the composite rod reinforcement is determined by the moment of softening of the composite rod matrix as a result of heating under fire conditions. The maximum temperature for various composite materials is 150 °Ñ – 250 °C. When designing, it is necessary to ensure the normative value of the limit of fire resistance of structures. For the bearing structures of the frame, the fire resistance limit corresponds to the moment of loss of the bearing capacity, for the intermediate floors – the loss of bearing capacity, integrity and thermal insulation ability. The main factor that provides the fire resistance of concrete structures with rod composite reinforcement is the thickness of the protective layer of concrete which ensures the joint operation of composite rods with concrete. Diagrams of the temperature change over the thickness of a concrete structure are presented, on the basis of them the methodology for the assignment of the value of the protective layer of concrete for the core composite reinforcement for different designs with due regard for the duration of fire effect in case of fire is proposed. The nomenclature of structures in which it is possible to use the rod composite reinforcement with the provision of regulatory requirements for the limit of fire resistance is determined.

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.

A Study of Rehabilitation of Exisisting Concrete Structures

2012 ◽  
Vol 3 (4) ◽  
pp. 79-81
Author(s):  
Prof. Y. R. Suryavanshi Prof. Y. R. Suryavanshi ◽  
◽  
Vardan Chandnani ◽  
Prasad Dhumal ◽  
Sohabran Singh Pundir ◽  
...  
Keyword(s):  
Concrete Structures
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