Abstract

Corrosion of carbon steel rebar in concrete structures, such as highway bridges and buildings, has a direct impact on their structural integrity since the rebar provides the tensile strength within the structure. Rebar strength depends on the remaining effective radius of a given rod. Long-time decay up to 0.1 s, in the transient response of pulsed eddy current (PEC), was examined as a potential method to quantify general corrosion in ferromagnetic rebar. The transient response of a coaxial solenoidal drive–receive coil pair, oriented parallel to the rebar axis, was analyzed over a range of distances into the concrete (liftoff) and rebar radii. At long times, the single exponential decay constant was largely independent of liftoff. A power law relationship for the characteristic decay time, consistent with long-time diffusion of electromagnetic fields into a rod, was observed. The intercept of a best-fit line to measured voltage decay decreased exponentially with liftoff and maintained a measurable response up to 110 mm distance for a 25 mm (1 in.) diameter rebar. This exponential decay was present in 22 mm (7/8 in.), 19 mm (3/4 in.), and 15 mm (5/8 in.) samples as well. Reported results demonstrate the potential for PEC to quantify remaining cross-sectional area of rebar in concrete structures.

References

References
1.
Corrosionpedia
,
2018
, “
Rebar Corrosion
,” https://www.corrosionpedia.com/definition/1380/rebar-corrosion, Accessed September 30, 2019.
2.
Boysen
,
E.
, and
Muir
,
N. C.
,
2011
,
Nanotechnology for Dummies
,
John Wiley & Sons Inc.
,
New York
.
3.
Perkins
,
P. H.
,
2019
,
Swimming Pools: Design and Construction
,
CRC Press
,
Boca Raton, FL
.
4.
Stewart
,
M. G.
,
2009
, “
Mechanical Behaviour of Pitting Corrosion of Flexural and Shear Reinforcement and Its Effect on Structural Reliability of Corroding RC Beams
,”
Struct. Saf.
,
31
(
1
), pp.
19
30
. 10.1016/j.strusafe.2007.12.001
5.
Zhao
,
Y.
,
Karimi
,
A. R.
,
Wong
,
H. S.
,
Hu
,
B.
,
Buenfeld
,
N. R.
, and
Jin
,
W.
,
2011
, “
Comparison of Uniform and Non-Uniform Corrosion Induced Damage in Reinforced Concrete Based on a Gaussian Description of the Corrosion Layer
,”
Corros. Sci.
,
53
(
9
), pp.
2803
2814
. 10.1016/j.corsci.2011.05.017
6.
B. Products
,
2017
,
What Are the Different Types of Rebar?
BN Products
,
Wickenburg, AZ
.
7.
415 Steel
,
2018
, “
TMT Bars—Thermo-Mechanically Treated Bars—An Introduction
,” http://rightsteel.in/tmt-bars-thermo-mechanically-treated-bars-an-introduction/, Accessed September 27, 2019.
8.
NDT Resource Center
,
2012
, “
Thermal Treatments (Heat-Treating)
,” https://www.nde-ed.org/EducationResources/CommunityCollege/Materials/Structure/thermal.htm, Accessed August 8, 2020.
9.
Landgraf
,
F. J. G.
, and
Emura
,
M.
,
2002
, “
Losses and Permeability Improvement by Stress Relieving Fully Processed Electrical Steels With Previous Small Deformations
,”
J. Magn. Magn. Mater.
,
242
, pp.
152
156
. 10.1016/S0304-8853(01)01184-2
10.
A.
Kiganda
,
2017
, “
Ribbed Steel Bars Reinforcement: Reliable reinforcement
,” Construction Review Online, https://constructionreviewonline.com/2017/01/ribbed-steel-bars-reinforcement-reliable-reinforcement/
11.
Song
,
H.-W.
, and
Saraswathy
,
V.
,
2007
, “
Corrosion Monitoring of Reinforced Concrete Structures—A Review
,”
Int. J. Electrochem. Sci.
,
2
, pp.
1
27
.
12.
Szymanik
,
B.
,
Frankowski
,
P. K.
,
Chady
,
T.
,
Robinson
,
C.
, and
John
,
A.
,
2016
, “
Detection and Inspection of Steel Bars in Reinforcement Concrete Structures Using Active Infrared Thermography With Microwave Excitation and Eddy Current Sources
,”
Sensors
,
16
(
2
), p.
234
.
13.
Zhang
,
H.
,
Yang
,
R.
,
He
,
Y.
,
Foudazi
,
A.
,
Cheng
,
L.
, and
Tian
,
G.
,
2017
, “
A Review of Microwave Thermography Nondestructive Testing and Evaluation
,”
Sensors
,
17
(
5
), p.
1123
.
14.
Advantages and Disadvantages of Selected Non-Destructive Inspection Methods (NDI)
,” Engineers Edge,
2020
, https://www.engineersedge.com/inspection/inspection_pro_con.htm, Accessed May 10, 2020.
15.
Fromme
,
P.
,
2013
, “
Noncontact Measurement of Guided Ultrasonic Wave Scattering for Fatigue Crack Characterization
,”
Proc. SPIE Int. Soc. Opt. Eng.
,
8692
, p.
86921N
.
16.
Mukherjee
,
I.
,
Patil
,
J.
,
Banerjee
,
S.
, and
Tallur
,
S.
,
2020
, “
Phase Sensitive Detection of Extent of Corrosion in Steel Reinforcing Bars Using Eddy Currents
,” https://arxiv.org/ftp/arxiv/papers/2001/2001.03756.pdf, Accessed August 8, 2020.
17.
Ulapane
,
N.
,
Wickramanayake
,
S.
, and
Kodagoda
,
S.
,
2019
, “Pulsed Eddy Current Sensing for Condition Assessment of Reinforced Concrete,” https://www.researchgate.net/publication/333506403_Pulsed_Eddy_Current_Sensing_for_Condition_Assessment_of_Reinforced_Concrete, Accessed May 10, 2020.
18.
Desjardins
,
D. P. R.
,
Krause
,
T. W.
, and
Clapham
,
L.
,
2015
, “
Transient Response of a Driver-Pick-Up Coil Probe in Transient Eddy Current Testing
,”
Nondestruct. Test. Eval. Int.
,
17
, pp.
8
14
. 10.1016/j.ndteint.2015.04.008
19.
Buck
,
J. A.
,
Underhill
,
P. R.
,
Mokros
,
S. G.
,
Morelli
,
J. E.
,
Babbar
,
V. K.
,
Lepine
,
B.
,
Renaud
,
J.
, and
Krause
,
T. W.
,
2015
, “
Pulsed Eddy Current Inspection of Support Structures in Steam Generators
,”
IEEE Sens. J.
,
15
(
8
), pp.
4305
4312
. 10.1109/JSEN.2015.2418220
20.
Krause
,
T. W.
,
McGregor
,
R. J.
,
Tetervak
,
A.
, and
Underhill
,
P. R.
,
2015
, “
Pulsed Eddy Current Sensor For Precision Measurement At-Large Lift-Offs on Metallic Surfaces
,” Patent No. 9,091,664 B2.
21.
Lara
,
P. F.
,
1989
, “
Transient Electromagnetic Method for Detecting Corrosion on Conductive Containers Having Variations in Jacket Thickness
,” Patent No. 4,843,319.
22.
Wwedensky
,
v. B.
, “
Concerning the Eddy Currents Generated by a Spontaneous Change of Magnetization (Translated—Jan. 2008)
,”
Ann. Phys.
,
64
(
1921
), p.
1921
.
23.
Bean
,
L. B.
,
DeBlois
,
C. P.
, and
Nesbitt
,
R. W.
,
1959
, “
Eddy-Current Method for Measuring the Resistivity of Metals
,”
J. Appl. Phys.
,
30
(
12
), pp.
1976
1980
. 10.1063/1.1735100
24.
Ohanian
,
H. C.
,
1983
, “
On the Approach to Electro-and Magneto-Static Equilibrium
,”
Am. J. Phys.
,
51
(
11
), pp.
1020
1022
. 10.1119/1.13364
25.
Jackson
,
J. D.
,
1999
, “Magnetostatics, Faraday’s Law, Quasi-Static Fields,”
Classical Electrodynamics
,
John Wiley and Sons
,
Hoboken
, p.
17423
.
26.
Desjardins
,
D.
,
2015
, “
Analytical Modeling for Transient Probe Response in Eddy Current Testing
,” p.
1
175
.
27.
E. Tutorials
,
2019
, “
Resistivity
,”
Aspencore
, https://www.electronics-tutorials.ws/resistor/resistivity.html, Accessed February 10, 2019.
28.
Sutherland
,
K.
,
Monica
,
M.
, and
Elert
,
G.
,
2015
, “
Density of Steel
,” The Physics Factbook, 2004, https://hypertextbook.com/facts/2004/KarenSutherland.shtml
29.
Cecco
,
V. S.
,
Drunen
,
G. V. A. N.
, and
Sharp
,
F. L.
,
1983
, “
Eddy Current Manual Volume 1
,” Chalk River Nuclear Laboratories, AECL-7523, November 1981, pp.
163
195
.
30.
H. S. Solutions
, “
Steel Rebar Sizes & Rebar Stock
,” https://www.harris supplysolutions.com/steel-rebar-sizes-stock.html, Accessed October 15, 2018.
31.
Staff
,
C. C.
,
2005
, “
Placing Reinforcing Steel
,” https://www.concreteconstruc tion.net/how-to/construction/placingreinforcing-steel_o, Accessed August 8, 2020.
32.
MathWorks
,
2019
, “
Fit Curves and Surfaces to Data Using Regression, Interpolation, and Smoothing
.”
33.
Eddy
,
I. C.
,
Underhill
,
P. R.
,
Morelli
,
J.
, and
Krause
,
T. W.
,
2019
, “
Pulsed Eddy Current Response to Liftoff in Different Sizes of Concrete Embedded Rebar
,”
IEEE Sens.
,
3
, pp.
1
4
. 10.1109/sensors43011.2019.8956833
34.
Krause
,
T. W.
,
Mandache
,
C.
, and
Lefebvre
,
J. H. V.
,
2008
,”
Diffusion of Pulsed Eddy Currents in Thin Conducting Plates
,”
27
(
1
), pp.
368
375
.
35.
Alberta
,
C.
,
2016
, “
A Guide for Durable Residential Concrete Flatwork 2016 Revision
,” http://www.concretealberta.ca/uploads/files/Documents/A%20Guide%20for%20Durable%20Quality%20Residential%20Concrete%20Flatwork%202 016%20Revision.pdf, Accessed August 8, 2020.
You do not currently have access to this content.