Determination of Specific Electrical Resistance and Carbonation Depth of Concrete in Reinforced Concrete Elements

2020 ◽  
Author(s):  
Ivan Ivanchev
Keyword(s):  
Reinforced Concrete ◽  
Electrical Resistance ◽  
Specific Electrical Resistance ◽  
Carbonation Depth ◽  
Concrete Elements

scholarly journals Analyzing of Coatings on Steel - Reinforced Concrete Elements by Mobile NMR

2016 ◽  
Vol 62 (1) ◽  
pp. 65-82 ◽  
Author(s):  
J. Orlowsky
Keyword(s):  
Reinforced Concrete ◽  
Potential Effect ◽  
Building Site ◽  
Steel Reinforced Concrete ◽  
Mobile Nmr ◽  
The Individual ◽  
First Time ◽  
Concrete Elements ◽  
Non Destructive

Abstract A large number of infrastructural concrete buildings are protected against aggressive environments by coating systems. The functionality of these coating systems is mainly affected by the composition and thickness of the individual polymeric layers. For the first time ever, a mobile nuclear magnetic resonance (NMR) sensor allows a non-destructive determination of these important parameters on the building site. However, before this technique can be used on steel-reinforced concrete elements, the potential effect of the reinforcement on the measurement, i.e. the NMR signal, needs to be studied. The results show a shift of the NMR profile as well as an increase of the signals amplitude in the case of the reinforced samples, while calculating the thickness of concrete coating leading to identical results.

scholarly journals TO DETERMINATION OF THE CRACKING MOMENT FOR BENDING REINFORCED CONCRETE ELEMENTS WITH ACCOUNT OF PLASTIC DEFORMATIONS OF CONCRETE IN THE TENSION AREA

2018 ◽  
Vol 3 (3) ◽  
pp. 30-38
Author(s):  
О.В. Радайкин ◽  
Oleg Radaykin
Keyword(s):  
Reinforced Concrete ◽  
Deformation Model ◽  
Conventional Concrete ◽  
Class A ◽  
Standard Calculation ◽  
Plasticity Coefficient ◽  
Concrete Elements ◽  
Nonlinear Deformation Model ◽  
Good Agreement

At the standard calculation of the cracking moment for bending reinforced concrete elements the plasticity coefficient γ is normally used, which according to SP 63.13330.2012 is 35% less than in the old SNiP 2.03.01-84*. The question arises, what is the reason for such a noticeable difference and which of the methods gives more reliable results? This article seeks to answer this question. For this purpose the physical meaning of the coefficient γ was considered in detail, with the usage of a nonlinear deformation model of a normal section. A calculation formula for γ depending on an element’s reinforcement degree was obtained, which is valid for conventional concrete of B15-B35 class. A comparison of the calculated cracking moment according to the proposed method with experiments by the other authors was carried out. A good agreement of results was observed.

scholarly journals A Method For Determination Of Specific Electrical Resistance Of Steel And Nano-Coating Sputtered On It

2015 ◽  
Vol 2 ◽  
pp. 118 ◽  
Author(s):  
Andris Martinovs ◽  
Josef Timmerberg ◽  
Konstantins Savkovs ◽  
Aleksandrs Urbahs ◽  
Paul Beckmann
Keyword(s):  
Electrical Conductivity ◽  
Magnetic Permeability ◽  
Electrical Resistance ◽  
Skin Effect ◽  
Specific Electrical Resistance ◽  
Specific Electrical Conductivity ◽  
Relative Magnetic Permeability ◽  
Nano Coating ◽  
Cylindrical Steel

The paper describes methods developed to determine specific electrical conductivity and relative magnetic permeability of cylindrical steel items and nano-coatings deposited on them by sputtering. Research enables development of a new method for determination of thickness of vacuum deposited nano- coating that is based on application of skin effect.

Carbon reinforced concrete and temperature

2019 ◽  
Author(s):  
Frank Schladitz ◽  
Emanuel Lägel ◽  
Daniel Ehlig
Keyword(s):  
Electrical Conductivity ◽  
Reinforced Concrete ◽  
Electrical Resistance ◽  
Manufacturing Process ◽  
Fresh Concrete ◽  
Building Construction ◽  
Specific Electrical Resistance ◽  
Temperature Stresses ◽  
Different Temperatures ◽  
Construction Practice

<p>Carbon reinforced concrete — a combination of non-corroding carbon reinforcement and concrete — has been investigated for over 20 years and has been used extensively in construction practice for more than 10 years for new constructions and for renovation. Wall and ceiling constructions in building construction as well as bridges and platform systems were newly erected, but also roofs, silos and bridges were renovated. During its manufacturing process but also during its time of use, carbon reinforced concrete can be affected by temperature stresses. The paper starts with an overview of how the temperature characteristics at different temperatures are to be evaluated. Furthermore, it will be shown how mat-like carbon reinforcement with its electrical conductivity and the high specific electrical resistance of approx. 16 Ω-mm²/m can be used for the deliberate heating of carbon concrete components. In addition, carbon reinforcement can be used to achieve thermal prestressing of fresh concrete components similar to prestressed glass panes.</p>

scholarly journals ASSESSMENT OF THE DEPTH AND RATE OF CORROSION IN STEEL REINFORCEMENT OF REINFORCED CONCRETE CULVERTS

2020 ◽  
Author(s):  
Alexandr Vasiliev ◽  
Svetlana Daškevič
Keyword(s):  
Reinforced Concrete ◽  
Protective Layer ◽  
Corrosion Damage ◽  
Steel Reinforcement ◽  
Operating Conditions ◽  
Protective Properties ◽  
Open Atmosphere ◽  
Concrete Elements ◽  
Corrosion State

Based on the results of many research years on concrete carbonisation: both immediately after manufacture (using heat-moisture treatment) and in reinforced concrete elements operated for the periods of various length (in an open atmosphere); the effect of carbonisation on the change in the protective properties of concrete in relation to steel reinforcement; for determination of the dependence of the corrosion state of steel reinforcement on the degree of concrete carbonisation in the area of steel reinforcement; the obtained regression dependences of the change (by time in the cross section) of the degree of concrete carbonisation of various classes in strength, – the analysis of the time of the onset of the boundary values of the degrees of concrete carbonisation (strength classes C12/15–C30/37) for the operating conditions of the open atmosphere was performed. Based on it, the regression dependences of the time variation of the depth of corrosion damage of steel reinforcement were construed (for fixed thicknesses of the concrete protective layer). The obtained nature of dependences made it possible to offer, in a general form, the regression dependences of the depth of corrosion damage and corrosion rate of steel reinforcement for concretes (strength classes C12/15–C30/37) for operating conditions in open atmosphere.

To Determination of Stresses in the Stretched Armature of Extracredly Compressed Elements in the Limit Condition

2019 ◽  
Vol 974 ◽  
pp. 556-563
Author(s):  
Evgeniy N. Peresypkin ◽  
Sergey E. Peresypkin
Keyword(s):  
Reinforced Concrete ◽  
Linear Dependence ◽  
Boundary Value ◽  
Limit State ◽  
Limit Condition ◽  
Equal Strength ◽  
Points Of View ◽  
Concrete Elements

The problem of determining stresses in a stretched reinforcement of inflexible eccentric-compressed reinforced concrete elements is considered when the height of the compressed zone in the limit state exceeds its boundary value corresponding to the condition of equal strength of the section. Instead of the generally accepted linear dependence of the stresses under consideration on the height of the compressed zone, an elliptic relationship more expedient from different points of view has been proposed.

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