scholarly journals Determination of the Real Cracking Moment of Two Reinforced Concrete Beams through the Use of Embedded Fiber Optic Sensors

Sensors ◽  
2020 ◽  
Vol 20 (3) ◽  
pp. 937 ◽  
Author(s):  
Julián García Díaz ◽  
Nieves Navarro Cano ◽  
Edelmiro Rúa Álvarez
Keyword(s):  
Reinforced Concrete ◽  
Concrete Beams ◽  
Reinforced Concrete Beams ◽  
Optic Fiber ◽  
Fiber Sensors ◽  
The Real ◽  
Maximum Flexion ◽  
Flexion Moment ◽  
The Moment

This article investigates the possibility of applying weldable optic fiber sensors to the corrugated rebar in reinforced concrete structures to detect cracks and measure the deformation of the steel. Arrays have initially been designed comprised of two weldable optic fiber sensors, and one temperature sensor to compensate its effect in measuring deformations. A series of tests were performed on the structures to evaluate functioning of the sensors, and the results obtained from the deformation measures shown by the sensors have been stored using specific software. Two reinforced concrete beams simply resting on the support have been designed to perform the tests, and they have been monitored in the zones with maximum flexion moment. Different loading steps have been applied to the beams at the center of the span, using a loading cylinder, and the measurement of the load applied has been determined using a loading cell. The analysis of the deformation measurements of the corrugated rebar obtained by the optic fiber sensors has allowed us to determine the moment at which the concrete has cracked due to the effect of the loads applied and the deformation it has suffered by the effect of the different loading steps applied to the beams. This means that this method of measuring deformations in the corrugated rebar by weldable optic fiber sensors provides very precise results. Future lines of research will concentrate on determining an expression that indicates the real cracking moment of the concrete.

scholarly journals Reinforced concrete beams coated with fiberglass-reinforced polymeric profiles as partial substitutes for the transverse reinforcement

2020 ◽  
Vol 13 (6) ◽  
Author(s):  
Igor Souza Hoffman ◽  
Jorge Henrique Piva ◽  
Augusto Wanderlind ◽  
Elaine Guglielmi Pavei Antunes
Keyword(s):  
Reinforced Concrete ◽  
Composite Structures ◽  
Mechanical Performance ◽  
Concrete Beams ◽  
Reinforced Concrete Beams ◽  
Fiber Reinforced Polymers ◽  
Transverse Reinforcement ◽  
Structural Applications ◽  
The Moment ◽  
The One

abstract: The use of GFRP (Glass Fiber Reinforced Polymers) structural profiles in the construction sector is growing due to their attractive properties, such as high mechanical strength and durability in aggressive environments. With this, it is necessary to conduct studies that deepen the knowledge about the performance of these materials in structural applications. Therefore, this work aims to analyze the mechanical performance of reinforced concrete beams coated with GFRP profiles, in comparison to reinforced concrete beams, by analyzing groups with different spacing between transversal reinforcement. In all groups there was no change in the longitudinal reinforcement, and the D and Q groups were, respectively, made up of transverse reinforcement spaced twice and quadruple the one calculated for the reference beams, and presented the GFRP profiles in their constitution. All beams were tested at four-point bending, and strain gauges were installed in one of the beams of each group studied. The results obtained in the tests showed an increase in strength of 83.67% in the beams of group D, and 79.91% for group Q, in relation to the references. The analysis of longitudinal deformations made it possible to verify increases in stiffness and the moment of cracking in composite beams. Thus, based on this study, the composite structures studied may constitute future solutions for constructions exposed to aggressive environmental conditions, in order to increase their durability and also to contribute to the design of such structural elements with lower reinforcement rates.

scholarly journals Influence of the percentage of reinforcement by unstressed rebar on the deformability of pre-stressed RC beams

2021 ◽  
Vol 27 (3) ◽  
pp. 212-216
Author(s):  
Yaroslav Blikharskyy ◽  
Jacek Selejdak ◽  
Taras Bobalo ◽  
Roman Khmil ◽  
Mykhailo Volynets
Keyword(s):  
Reinforced Concrete ◽  
Concrete Beams ◽  
Bending Moment ◽  
Reinforced Concrete Beams ◽  
Practical Significance ◽  
Pure Bending ◽  
Static Loads ◽  
Steel Bars ◽  
Periodic Profile

Abstract This article presents the materials of deformability studies of pre-stressed steel-concrete beams reinforced with a package of reinforcement with different ratio of tape and rebar in the pure bending moment zone. The aim of the research was determination of the reinforcement percentage influence, for pre-stressed reinforced concrete beams reinforced with a package of reinforcement on their deformability. Also, the aim was to evaluate the effectiveness of using pre-stressed rebar in combined reinforcement. The practical significance of the experimental research is to study the deformability in pre-stressed bending elements with external tape and rebar reinforcement, taking into account the influence of different ratios of reinforcement areas within the combined reinforcement and development of proposals for such structures` calculation and design. The scientific novelty of the research is in obtaining the deformability characteristics of reinforced concrete beams reinforced with a package of reinforcement (tape and steel bars with periodic profile) with different ratios in the case of static loads` action.

scholarly journals Calculation of steel-reinforced concrete beam for instant loading taking into account the non-linearity of the concrete diagram ε-σ

2020 ◽  
Vol 17 (2) ◽  
pp. 85-94
Author(s):  
S. O. Chepilko ◽  
Keyword(s):  
Reinforced Concrete ◽  
Concrete Beam ◽  
Concrete Beams ◽  
Reinforced Concrete Beam ◽  
Neutral Axis ◽  
Reinforced Concrete Beams ◽  
System Of Equations ◽  
Nonlinear System Of Equations ◽  
Steel Reinforced Concrete

Issues of calculating steel-reinforced concrete beams are considered taking into account a nonlinear concrete diagram based on the Sargin formula. The nonlinear system of equations for determination of curvature and neutral axis, which is solved numerically, is written in explicit form. Explicit expressions for determination of other calculated quantities needed for design of steel-reinforced concrete beams are derived. Numerical examples are given. The analysis of accounting nonlinearity in comparison with the linear calculation is carried out.

Damage Assessment of Reinforced Concrete Beams by Complex Ratios of Transfer Functions

2006 ◽  
Vol 321-323 ◽  
pp. 357-362 ◽  
Author(s):  
Chih Peng Yu ◽  
Chia Chi Cheng ◽  
Chih Hung Chiang
Keyword(s):  
Reinforced Concrete ◽  
Transfer Functions ◽  
Concrete Beams ◽  
Field Tests ◽  
High Sensitivity ◽  
Reinforced Concrete Beams ◽  
Numerical Studies ◽  
Complex Ratio ◽  
Local Defects

In this paper, a newly developed approach for the determination of characteristics associated with local defects of a beam is briefly introduced. From the numerical studies carried out in this study, the complex ratio between two transfer functions associated with an imaginary intact beam and a damaged beam can provide such information. Based on the numerical studies, the rules in determining degree of damages and locations of defects were first briefly outlined. These idealized rules were then verified by experimental data obtained from dynamic tests of realistic specimens of simply-supported reinforced concrete beams. The preliminary results indicate that the defined ratio of transfer functions can potentially serve as an exaggerated indication for the degree of changes in certain modal responses. Thus, the proposed ratio of transfer functions can be used to assist system identification, while the nature of high sensitivity also restricts its direct application to certain complicated data associated with field tests. A variety of test setup for both receivers and impact sources were studied and the test results appear to agree with designated conditions of the specimens.

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