scholarly journals Historical reinforced concrete structures – used materials and calculating algorithms

2015 ◽  
Vol 14 (2) ◽  
pp. 105-112 ◽  
Author(s):  
Bartosz Szostak ◽  
Maciej Trochonowicz
Keyword(s):  
Mechanical Properties ◽  
Reinforced Concrete ◽  
Concrete Structures ◽  
Reinforced Concrete Structures ◽  
Structural Element ◽  
Historical Building ◽  
Historical Material ◽  
Low Strength ◽  
Concrete Elements

During designing in historical object we can have a problem with historical reinforced concrete elements. Many designers, classifies this elements as low strength. They are convicted that this type of elements in historical building can be only a monument and cannot be used in this construction as an structural element. It is very important in this type of buildings to keep as many historical material as it is possible. Authors researched the literature which has been a guide in the design and execution of these elements. By comprising used algorithms and physico-mechanical properties of old materials with algorithms and materials, which are using today, we are able to estimate the strength of such elements.

scholarly journals Optimizing of system "column-cfrp lamellas" with the strengthening of civil structures

2021 ◽  
Vol 9 (1) ◽  
pp. 1-5
Author(s):  
Irina Mayackaya ◽  
Batyr Yazyev ◽  
Anastasia Fedchenko ◽  
Denis Demchenko
Keyword(s):  
Reinforced Concrete ◽  
Composite Materials ◽  
Carbon Fiber ◽  
Concrete Structures ◽  
Polymeric Composite ◽  
Concrete Columns ◽  
Reinforced Concrete Structures ◽  
Structural Elements ◽  
Civil Structures ◽  
Concrete Elements

Reinforced concrete elements of structures in the form of columns, beams, ceilings are widely used in the construction of buildings and structures of industrial and civil construction. In most cases, the columns serve as supports for other building elements, for example, crossbars, slabs, girders, beams. One of the cycles of the work of reinforced concrete structures is the state of their repair and reconstruction, including the stages of strengthening the elements. There is a problem of strengthening of reinforced concrete columns. The article deals with the issue of reinforcing columns and other structural elements having a cylindrical surface, with polymeric composite materials in the form of carbon fiber lamellae. The use of composite materials allows to increase the service life and strength of reinforced concrete structures used in construction.

scholarly journals Seismic fragility assessment of existing sub-standard low strength reinforced concrete structures

2015 ◽  
Vol 14 (3) ◽  
pp. 439-452 ◽  
Author(s):  
Sohaib Ahmad ◽  
Nicolas Kyriakides ◽  
Kypros Pilakoutas ◽  
Kyriacos Neocleous ◽  
Qaiser uz Zaman
Keyword(s):  
Reinforced Concrete ◽  
Concrete Structures ◽  
Seismic Fragility ◽  
Reinforced Concrete Structures ◽  
Low Strength

scholarly journals Estimation of the pull-off resistance models of reinforced concrete structures by a numerical method

2021 ◽  
Vol 350 ◽  
pp. 00011
Author(s):  
Mikalai Shalabyta ◽  
Elizabeth Matweenko ◽  
Nikifor Matweenko ◽  
Valery Rakhuba
Keyword(s):  
Numerical Modeling ◽  
Reinforced Concrete ◽  
Comparative Analysis ◽  
Strain State ◽  
Numerical Models ◽  
Tensile Force ◽  
Concrete Structures ◽  
Reinforced Concrete Structures ◽  
New Information ◽  
Concrete Elements

Comparative analysis of calculations of calculation numerical models for pulling out embedded parts in reinforced concrete structures is carried out. Based on the results of numerical modeling, new information about the stress-strain state in reinforced concrete elements from the local action of the tensile force has been obtained.

scholarly journals Calculation of damage RC constructions according to deformation model

2020 ◽  
Vol 2020 (2) ◽  
pp. 99-106
Author(s):  
Yaroslav Blikharskyy ◽  
Keyword(s):  
Mechanical Properties ◽  
Reinforced Concrete ◽  
Concrete Beams ◽  
Concrete Structures ◽  
Physical And Mechanical Properties ◽  
Reinforced Concrete Beams ◽  
Core Material ◽  
Deformation Model ◽  
Reinforced Concrete Structures ◽  
The Impact

This article presents results of a theoretical study of reinforced concrete beams with damaged reinforcement. The change of micro-hardness of a reinforcing rebar’s with a diameter of 20 mm of A500C steel in the radial direction is investigated and the thickness of the heat-strengthened layer is established. It is established that the thickness of the thermo-strengthened steel layer of the reinforcing bar with a diameter of 20 mm of A500C is approximately 3 mm. It is shown that the strength characteristics of this layer are on 50% higher compared to the core material of the rebar, while the plasticity characteristics are lower. The aim of the work is to determine the strength and deformability of reinforced concrete structures without damaging the reinforcement and in case of damage. Determining the impact of changes in the physical characteristics of reinforcement on the damage of reinforced concrete structures, according to the calculation to the valid norms, in accordance with the deformation model. To achieve the goal of the work, theoretical calculations of reinforced concrete beams were performed according to the deformation model, according to valid norms. This technique uses nonlinear strain diagrams of concrete and rebar and is based on an iterative method. According to the research program 3 beam samples were calculated. Among them were undamaged control sample with single load bearing reinforcement of ∅20 mm diameter – BC-1; sample with ∅20 mm reinforcement with damages about 40% without changes in the physical and mechanical properties of reinforcement – BD-2 and sample with ∅20 mm reinforcement with damages about 40% with changes in the physical and mechanical properties of reinforcement – BD-3. The influence of change of physical and mechanical characteristics of rebar’s on bearing capacity of the damaged reinforced concrete beams is established.

scholarly journals The Mechanical Properties of Centrifuged Concrete in Reinforced Concrete Structures

2020 ◽  
Vol 10 (10) ◽  
pp. 3570
Author(s):  
Romualdas Kliukas ◽  
Ona Lukoševičienė ◽  
Arūnas Jaras ◽  
Bronius Jonaitis
Keyword(s):  
Mechanical Properties ◽  
Reinforced Concrete ◽  
Concrete Strength ◽  
Concrete Structures ◽  
High Strength ◽  
Reinforcement Ratio ◽  
Transverse Reinforcement ◽  
Reinforced Concrete Structures ◽  
Test Results ◽  
Moduli Of Elasticity

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.

Effect of the ITZ Damage on Durability of Reinforced Concrete in Chloride Environment

1994 ◽  
Vol 370 ◽  
Author(s):  
Raoul François ◽  
Ginette Arliguie
Keyword(s):  
Reinforced Concrete ◽  
Service Life ◽  
Concrete Structures ◽  
Operating Conditions ◽  
Reinforced Concrete Structures ◽  
Actual Operating ◽  
Chloride Environment ◽  
Concrete Elements ◽  
Transfer Properties ◽  
Salt Fog

AbstractThis paper deals with the effect of the ITZ on the service life of reinforced concrete. In the case of reinforced concrete structures, the penetration of chlorides does not depend only on concrete transfer properties but also on the loading applied, on the state of strains and on the exposure to the aggressive environment.In order to take into account these different parameters, we have performed experiments on reinforced concrete elements, over a long period. The samples used have to be of an adequate size (3 meters long) and stored in a salt fog in a loading state so as to be representative of the actual operating conditions of the reinforced concrete structures.The bending of the beams leads to the development of cracks which are neither preceded nor accompanied by microcracks, but the cement paste-aggregate interfaces are damaged in the tensile areas.The service loading of reinforced concrete has two consequences : firstly, a cracking with widths ranging between 0.05 mm and 0.5 mm according to the intensity of the mechanical strength applied. Secondly, a damage of the ITZ in the tensile areas causing an increase of chloride penetration directly proportional to the intensity of the stress applied to the beam.The model of the development of corrosion, worked out in relation with time and based on our results, emphasizes the influence of the paste-aggregate interface damage on the duration of the service life.

Strength of Normal and Inclined Sections of Bent Reinforced Concrete Elements with Zone Reinforcement Made of Steel Fiber

2022 ◽  
Vol 906 ◽  
pp. 7-15
Author(s):  
Dmitry Utkin
Keyword(s):  
Reinforced Concrete ◽  
Dynamic Loading ◽  
Calculation Method ◽  
Steel Fiber ◽  
Experimental Studies ◽  
Concrete Structures ◽  
Dynamic Loads ◽  
Reinforced Concrete Structures ◽  
Short Term ◽  
Concrete Elements

On the basis of theoretical and experimental studies, the prerequisites and the method of calculation of bent and compressed-curved reinforced concrete structures with zone reinforcement made of steel fiber, working under static and short-term dynamic loads, are formulated. In the developed method for calculating the strength of normal and inclined sections, a nonlinear deformation model is implemented, which is based on the actual deformation diagrams of materials. The developed calculation method is brought to the program of calculation of reinforced concrete structures with zone reinforcement of steel fiber under short-term dynamic loading, taking into account the inelastic properties of materials. The numerical studies made it possible to determine the influence of various parameters of steel-fiber reinforcement on the strength of reinforced concrete elements. To confirm the main results of the developed calculation method, experimental studies of reinforced concrete beam structures reinforced with conventional reinforcement and a zone steel-fiber layer are planned and carried out. Experimental studies were carried out under static and short-term dynamic loads. As a result of the conducted experiments, data were obtained that characterize the process of destruction, deformation and cracking of steel-reinforced concrete elements under such types of loading. The dependences of changes in the energy intensity of reinforced concrete structures with zone reinforcement made of steel fiber in the compressed and stretched cross-section zones under dynamic loading are obtained. The effectiveness of the use of fiber reinforcement of normal and inclined sections of bent and compressed-curved elements to improve the strength and deformative.

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