scholarly journals STRENGTH AND STIFFNESS OF REINFORCED CONCRETE BEAMS MADE ON EXPERIMENTAL COMPOSITION OF A CONCRETE GOODS PLANT

2021 ◽  
Vol 11 (1) ◽  
pp. 34-38
Author(s):  
Dmitrii S. TOSHIN ◽  
Ekaterina E. KHUTOVA ◽  
Yulia V. ASTAEVA
Keyword(s):  
Reinforced Concrete ◽  
Construction Industry ◽  
Concrete Beams ◽  
Reinforced Concrete Beams ◽  
Control Measures ◽  
Reinforced Concrete Structures ◽  
Concrete Mixtures ◽  
Strength And Stiffness ◽  
Reliability Of Operation ◽  
Dominant Parameter

One of the options for optimization in the activities of the construction industry plants is the improvement of the composition of concrete mixtures, which requires control measures to assess indicators that ensure the reliability of operation of concrete and reinforced concrete structures. The strength of concrete in standard control cubes is at the same time the dominant parameter that determines the prospects of changes in production. The presented work presents the results of a comprehensive assessment of experimental concrete on cubes, prisms and reinforced concrete beams.

Non-Destructive Vibration Tests on Reinforced Concrete Structures

2015 ◽  
Vol 660 ◽  
pp. 186-191 ◽  
Author(s):  
Marina Lute
Keyword(s):  
Reinforced Concrete ◽  
Dynamic Response ◽  
Concrete Beams ◽  
Concrete Structures ◽  
Reinforced Concrete Beams ◽  
Reinforced Concrete Structures ◽  
Linear Behavior ◽  
Non Linear ◽  
Vibration Tests ◽  
Non Destructive

The purpose of this paper is looking at the dynamic response of existing reinforced concrete structures which have possibly sustained various levels of damage, a set of tests need to be identified that will be able to detect damage and quantify the damage if damage exists. In this work it is presented a further study on the effect of damage on the behavior of reinforced concrete beams. In particular, the non-linear behavior of these beams is considered once significant cracking has been introduced, outlining the stage of testing carried out in dynamic field.

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 PROPERTIES OF PITTING CORROSION OF STEEL REINFORCEMENT OF REINFORCED CONCRETE BEAMS

2017 ◽  
Vol 2 (3) ◽  
pp. 32-36
Author(s):  
Дронов ◽  
Andrey Dronov
Keyword(s):  
Reinforced Concrete ◽  
Pitting Corrosion ◽  
Concrete Beams ◽  
Concrete Structures ◽  
Steel Reinforcement ◽  
Reinforced Concrete Beams ◽  
Reinforced Concrete Structures ◽  
Damage Distribution ◽  
Chloride Environment ◽  
Corrosion Of Steel

Two types of steel reinforcement depassivation process: carbonation of concrete and chloride penetration are considered in the article. The comparison between the corrosion due to carbonation of concrete and the chloride-induced corrosion was carried out. It was found out, that chlorides induced corrosion is potentially more dangerous than that resulting from carbonation. Method of durable tests of reinforced concrete structures under the action of the gravitational load and the corrosive chloride environment is described in the article. The results of experimental research on reinforced concrete structures with corrosive damages to steel reinforcement are given in the article. The properties of corrosion cracking in the case of the pitting corrosion were determined. The character of corrosive damage distribution along the reinforcement bars and its effect on the strength of reinforced concrete beams were determined.

Experimental Study on Flexural Behavior of Reinforced Concrete Beams with Variety Lap Splices of Reinforcing Steel Bars

2016 ◽  
Vol 845 ◽  
pp. 132-139
Author(s):  
Mochamad Teguh ◽  
Novia Mahlisani
Keyword(s):  
Experimental Study ◽  
Reinforced Concrete ◽  
Concrete Beams ◽  
Reinforced Concrete Beams ◽  
Flexural Behavior ◽  
Reinforced Concrete Structures ◽  
Reinforcing Steel ◽  
Reinforcing Bars ◽  
Lap Splices ◽  
Steel Bars

The limited lengths of reinforcing bars have been commonly found in the practical construction of most reinforced concrete structures. The required length of a bar may be longer than the available stock of steel length. For maintaining desired continuity of the reinforcement in almost all reinforced concrete structures, some reinforcing bars should be carefully spliced. In the case of long flexural beam, bar installers end up with two or even more pieces of steel that must be spliced together to accomplish the desired steel length. An experimental study was conducted to investigate flexural behavior of reinforced concrete beams utilizing a variety lap splices of reinforcing steel bars under two-point loading. Five variations of lap splices of reinforcing steel bars positioned at midspan of tensile reinforcement of the beam were investigated. Welded joints and overlapped splices were used to construct the variation of lap splices of reinforcing steel bars. The general trend in crack pattern, the load deflection characteristics and the mode of failure of flexural beams under two-point loading were also observed. The flexural strength comprising load-displacement response, flexural crack propagation, displacement ductility is briefly discussed in this paper.

Performance Analysis of Reinforced Concrete Structures Strengthened with BFRP

2013 ◽  
Vol 712-715 ◽  
pp. 966-969 ◽  
Author(s):  
Ze Bao Kan ◽  
Yan Ru Li
Keyword(s):  
Mechanical Properties ◽  
Reinforced Concrete ◽  
Performance Analysis ◽  
Seismic Performance ◽  
Present Status ◽  
Concrete Structure ◽  
Concrete Beams ◽  
Reinforced Concrete Beams ◽  
Reinforced Concrete Structures ◽  
Reinforced Concrete Structure

The present status of reinforced concrete structure confined by FRP is introduced, and the recent technical researches of reinforced concrete beams and columns confined by BFRP are summarized. Based on those researches, the mechanical properties and calculation models are analyzed. At the same time, the seismic performance of reinforced concrete beams and columns confined by BFRP is also explored.

scholarly journals DEFLECTION OF FLEXURAL REINFORCED CONCRETE STRUCTURES WITH EXTERNAL NON-METALLIC REINFORCEMENT (EXPERIMENTAL AND THEORETICAL INVESTIGATION)

2002 ◽  
Vol 8 (3) ◽  
pp. 164-168
Author(s):  
Juozas Valivonis
Keyword(s):  
Reinforced Concrete ◽  
Theoretical Investigation ◽  
Concrete Beams ◽  
Theoretical Calculations ◽  
Concrete Structures ◽  
Reinforced Concrete Beams ◽  
Experimental Investigations ◽  
Reinforced Concrete Structures ◽  
Metallic Reinforcement ◽  
Good Agreement

In many cases concrete structures with prestressed steel being sufficiently strong do not meet requirements for stiffness. It is possible to avoid steel prestressing in concrete structures by means of providing additional non-metallic reinforcement, which gives opportunity to increase stiffness of beams significantly. Experimental investigations of reinforced concrete beams with external non-metallic reinforcement were made. Method for calculation of deflection of beams with external non-metallic reinforcement is presented in this article. Theoretical calculations of deflections using the proposed method were performed. Sufficiently good agreement with experimental deflection values was obtained.

scholarly journals Temperature distribution based on fire resistance tests in fiberglass reinforced concrete beams

2021 ◽  
Vol 18 (3) ◽  
pp. 54-63
Author(s):  
N. V. Begunova ◽  
◽  
V. N. Vozmishchev ◽  
Keyword(s):  
Reinforced Concrete ◽  
Temperature Distribution ◽  
Working Conditions ◽  
Fire Resistance ◽  
Concrete Beams ◽  
Test Laboratory ◽  
Reinforced Concrete Beams ◽  
Reinforced Concrete Structures ◽  
Fire Tests ◽  
Resistance Tests

The article presents the results of the study on the temperature distribution in fiberglass reinforced concrete beams produced by the KomAR in accordance with TU 2296-001-24488682-2014, on the basis of fire tests conducted in the test laboratory and test center for fire safety at the FGBU VNIIPO of EMERCOM of Russia. The value of the coefficient of working conditions of fiberglass rebar γ st is determined by analogy with SP 27.13330.2017 «Concrete and reinforced concrete structures designed to work in conditions of exposure to elevated and high temperatures», depending on the temperature.

Investigating the Load–Deflection of FRP Material in Concrete Beams Wrapped with CFRP in Universal Testing Machine (UTM)

2018 ◽  
Vol 15 (2) ◽  
pp. 744-751
Author(s):  
S. Margaret Jesse ◽  
V. M. Shanthi
Keyword(s):  
Reinforced Concrete ◽  
Failure Modes ◽  
Shear Failure ◽  
Concrete Beams ◽  
Testing Machine ◽  
Reinforced Concrete Beams ◽  
Flexural Failure ◽  
Reinforced Polymer ◽  
Cfrp Sheet ◽  
Strength And Stiffness

Strengthening Reinforced Concrete (RC) beams using FRP laminate becomes one of the main strengthening techniques. Failure of these beams is usually controlled by the bond strength between the laminate and the concrete. This paper presents the results of experimental investigation on six reinforced concrete beams, with various types, which were tested under two-point loading. The aim of the work was to study the efficacy of Carbon Fiber Reinforced Polymer (CFRP) sheets in enhancing the beam strength and stiffness from shear failure or flexural failure. The strengthening and deflection of the beams were carried out with cyclic loading. Experimental data on ultimate load, deflection and failure modes of each of the beams were obtained. For the comparison of CFRP sheet with cement concrete and the retrofitted specimens absorbs more energy, the CFRP beams yield a good result.

scholarly journals Shear Performance of Reinforced Concrete Beams with Small Circular Openings Strengthened Using Rectangular and Octagonal-Shaped Reinforcement

Materials ◽  
2020 ◽  
Vol 13 (24) ◽  
pp. 5804
Author(s):  
Hyeong-Gook Kim ◽  
Jung-Yoon Lee ◽  
Kil-Hee Kim
Keyword(s):  
Reinforced Concrete ◽  
Concrete Beams ◽  
Bending Moment ◽  
Reinforced Concrete Beams ◽  
Web Openings ◽  
Crack Control ◽  
Web Opening ◽  
Shear Performance ◽  
Strength And Stiffness ◽  
Cyclic Loading Tests

An experimental case study was carried out to investigate the shear performance of reinforced concrete beams with small circular openings under a cyclic anti-symmetric bending moment. The openings were strengthened by using a newly developed reinforcement continuously bent into rectangular and octagonal shapes, which was convenient for installation and effective for crack control. The presence of web opening reinforcement, the reinforcing method, and the web opening spacing were employed as main variables in the design of five specimens. The cyclic performance of all specimens was evaluated in terms of failure mode, crack pattern, strength and stiffness degradation, and strain distribution. Experimental results were discussed to assess the suitability of the proposed web opening reinforcement in RC web opening beams. It was confirmed that the proposed web opening reinforcement exhibited outstanding crack control and served as a shear resistance component in place of the concrete cross-section lost due to web openings. Finally, the shear strength of all specimens, obtained from the cyclic loading tests, were compared with those obtained from the equation proposed by Mansur (1998) and the Architectural Institute of Japan standard 2010.

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