performance of corrosion mitigation systems in iowa bridges · performance of corrosion mitigation...
TRANSCRIPT
![Page 1: Performance of Corrosion Mitigation Systems in Iowa Bridges · Performance of Corrosion Mitigation Systems in Iowa Bridges Work Performed on Behalf of Iowa Department of Transportation,](https://reader030.vdocuments.site/reader030/viewer/2022040714/5e1a72e62079c464e0745314/html5/thumbnails/1.jpg)
Performance of Corrosion Mitigation
Systems in Iowa Bridges
Work Performed on Behalf of Iowa Department of Transportation,
Michael Todsen
James P. Donnelly, Paul D. Krauss
and John S. LawlerWiss, Janney, Elstner Associates
![Page 2: Performance of Corrosion Mitigation Systems in Iowa Bridges · Performance of Corrosion Mitigation Systems in Iowa Bridges Work Performed on Behalf of Iowa Department of Transportation,](https://reader030.vdocuments.site/reader030/viewer/2022040714/5e1a72e62079c464e0745314/html5/thumbnails/2.jpg)
Application to 3 Iowa Bridges
• US 63 Ottumwa
– Cathodic Protection - Arc-sprayed zinc
• IA 192 Council Bluffs• IA 192 Council Bluffs
– Chloride extraction (ECE)
– Cathodic protection - Discrete anode
• I-380 Cedar Rapids
– Cathodic Protection – Zinc-hydrogel sheet
![Page 3: Performance of Corrosion Mitigation Systems in Iowa Bridges · Performance of Corrosion Mitigation Systems in Iowa Bridges Work Performed on Behalf of Iowa Department of Transportation,](https://reader030.vdocuments.site/reader030/viewer/2022040714/5e1a72e62079c464e0745314/html5/thumbnails/3.jpg)
Corrosion in Bridge Substructures
• Repair complicated and
expensive since
deck/superstructure must deck/superstructure must
be supported
• Exposure worst at leaking
joints
![Page 4: Performance of Corrosion Mitigation Systems in Iowa Bridges · Performance of Corrosion Mitigation Systems in Iowa Bridges Work Performed on Behalf of Iowa Department of Transportation,](https://reader030.vdocuments.site/reader030/viewer/2022040714/5e1a72e62079c464e0745314/html5/thumbnails/4.jpg)
Corrosion Process
electrolyte
Cathode
Anode
![Page 5: Performance of Corrosion Mitigation Systems in Iowa Bridges · Performance of Corrosion Mitigation Systems in Iowa Bridges Work Performed on Behalf of Iowa Department of Transportation,](https://reader030.vdocuments.site/reader030/viewer/2022040714/5e1a72e62079c464e0745314/html5/thumbnails/5.jpg)
Galvanic Protection
Sacrificial Anode CP
• Sacrificial anode
- Zinc sheets
- Arc-sprayed zinc
- Discrete probes
• Current flows by
Sacrificial
anode
Current
• Current flows by
galvanic action
• Proven record
• Lower initial cost
• Little maintenance
• Requires electrical
connection
Current
![Page 6: Performance of Corrosion Mitigation Systems in Iowa Bridges · Performance of Corrosion Mitigation Systems in Iowa Bridges Work Performed on Behalf of Iowa Department of Transportation,](https://reader030.vdocuments.site/reader030/viewer/2022040714/5e1a72e62079c464e0745314/html5/thumbnails/6.jpg)
Chloride Extraction
• Higher current
• Applied temporarily
• Electrolyte (water)
– Ponded
– Porous covering
• Current draws out
chlorides
• Time consuming
![Page 7: Performance of Corrosion Mitigation Systems in Iowa Bridges · Performance of Corrosion Mitigation Systems in Iowa Bridges Work Performed on Behalf of Iowa Department of Transportation,](https://reader030.vdocuments.site/reader030/viewer/2022040714/5e1a72e62079c464e0745314/html5/thumbnails/7.jpg)
![Page 8: Performance of Corrosion Mitigation Systems in Iowa Bridges · Performance of Corrosion Mitigation Systems in Iowa Bridges Work Performed on Behalf of Iowa Department of Transportation,](https://reader030.vdocuments.site/reader030/viewer/2022040714/5e1a72e62079c464e0745314/html5/thumbnails/8.jpg)
Application to 3 Iowa Bridges
• US 63 Ottumwa
– Cathodic Protection - Arc-sprayed zinc
• IA 192 Council Bluffs• IA 192 Council Bluffs
– Chloride extraction (ECE)
– Cathodic protection - Discrete anode
• I-380 Cedar Rapids
– Cathodic Protection – Zinc-hydrogel sheet
![Page 9: Performance of Corrosion Mitigation Systems in Iowa Bridges · Performance of Corrosion Mitigation Systems in Iowa Bridges Work Performed on Behalf of Iowa Department of Transportation,](https://reader030.vdocuments.site/reader030/viewer/2022040714/5e1a72e62079c464e0745314/html5/thumbnails/9.jpg)
US 63 Ottumwa
![Page 10: Performance of Corrosion Mitigation Systems in Iowa Bridges · Performance of Corrosion Mitigation Systems in Iowa Bridges Work Performed on Behalf of Iowa Department of Transportation,](https://reader030.vdocuments.site/reader030/viewer/2022040714/5e1a72e62079c464e0745314/html5/thumbnails/10.jpg)
Arc Sprayed Zinc CP
![Page 11: Performance of Corrosion Mitigation Systems in Iowa Bridges · Performance of Corrosion Mitigation Systems in Iowa Bridges Work Performed on Behalf of Iowa Department of Transportation,](https://reader030.vdocuments.site/reader030/viewer/2022040714/5e1a72e62079c464e0745314/html5/thumbnails/11.jpg)
![Page 12: Performance of Corrosion Mitigation Systems in Iowa Bridges · Performance of Corrosion Mitigation Systems in Iowa Bridges Work Performed on Behalf of Iowa Department of Transportation,](https://reader030.vdocuments.site/reader030/viewer/2022040714/5e1a72e62079c464e0745314/html5/thumbnails/12.jpg)
![Page 13: Performance of Corrosion Mitigation Systems in Iowa Bridges · Performance of Corrosion Mitigation Systems in Iowa Bridges Work Performed on Behalf of Iowa Department of Transportation,](https://reader030.vdocuments.site/reader030/viewer/2022040714/5e1a72e62079c464e0745314/html5/thumbnails/13.jpg)
![Page 14: Performance of Corrosion Mitigation Systems in Iowa Bridges · Performance of Corrosion Mitigation Systems in Iowa Bridges Work Performed on Behalf of Iowa Department of Transportation,](https://reader030.vdocuments.site/reader030/viewer/2022040714/5e1a72e62079c464e0745314/html5/thumbnails/14.jpg)
![Page 15: Performance of Corrosion Mitigation Systems in Iowa Bridges · Performance of Corrosion Mitigation Systems in Iowa Bridges Work Performed on Behalf of Iowa Department of Transportation,](https://reader030.vdocuments.site/reader030/viewer/2022040714/5e1a72e62079c464e0745314/html5/thumbnails/15.jpg)
![Page 16: Performance of Corrosion Mitigation Systems in Iowa Bridges · Performance of Corrosion Mitigation Systems in Iowa Bridges Work Performed on Behalf of Iowa Department of Transportation,](https://reader030.vdocuments.site/reader030/viewer/2022040714/5e1a72e62079c464e0745314/html5/thumbnails/16.jpg)
![Page 17: Performance of Corrosion Mitigation Systems in Iowa Bridges · Performance of Corrosion Mitigation Systems in Iowa Bridges Work Performed on Behalf of Iowa Department of Transportation,](https://reader030.vdocuments.site/reader030/viewer/2022040714/5e1a72e62079c464e0745314/html5/thumbnails/17.jpg)
30” by 48” test area
![Page 18: Performance of Corrosion Mitigation Systems in Iowa Bridges · Performance of Corrosion Mitigation Systems in Iowa Bridges Work Performed on Behalf of Iowa Department of Transportation,](https://reader030.vdocuments.site/reader030/viewer/2022040714/5e1a72e62079c464e0745314/html5/thumbnails/18.jpg)
Black wire from
Rebar Ground
Blue wire from
Ref. Halfcell
Resistor (0.1 ohm)
[Red to Black]
Red wire from
Zn Anode (coating)
Switch
(single toggle)
Meter setup to measure embedded reference halfcell
(+ to gnd [blk], - to cell [blue])
![Page 19: Performance of Corrosion Mitigation Systems in Iowa Bridges · Performance of Corrosion Mitigation Systems in Iowa Bridges Work Performed on Behalf of Iowa Department of Transportation,](https://reader030.vdocuments.site/reader030/viewer/2022040714/5e1a72e62079c464e0745314/html5/thumbnails/19.jpg)
Off
On
![Page 20: Performance of Corrosion Mitigation Systems in Iowa Bridges · Performance of Corrosion Mitigation Systems in Iowa Bridges Work Performed on Behalf of Iowa Department of Transportation,](https://reader030.vdocuments.site/reader030/viewer/2022040714/5e1a72e62079c464e0745314/html5/thumbnails/20.jpg)
US 63 Ottumwa - Arc Sprayed Zinc
• Current was minimal
• Total shift of test area only about 20 mV (Instant
off and depolarization)
• Blisters filled with zinc corrosion products have • Blisters filled with zinc corrosion products have
formed in coating (no chloride)
• Zinc coating thickness at blisters was 0.026” (0.018”
to 0.047”), [Spec was 0.020”]
• No initial data
• Minimal concrete deterioration
![Page 21: Performance of Corrosion Mitigation Systems in Iowa Bridges · Performance of Corrosion Mitigation Systems in Iowa Bridges Work Performed on Behalf of Iowa Department of Transportation,](https://reader030.vdocuments.site/reader030/viewer/2022040714/5e1a72e62079c464e0745314/html5/thumbnails/21.jpg)
US 63 Ottumwa - Arc Sprayed Zinc
Comments and Questions
• No site installation report was available
• Should install more than one test area and in both
highly exposed and lightly exposed areas
• When is protection lost due to blisters and zinc
consumption?
• Is it possible to consume all zinc applied?
![Page 22: Performance of Corrosion Mitigation Systems in Iowa Bridges · Performance of Corrosion Mitigation Systems in Iowa Bridges Work Performed on Behalf of Iowa Department of Transportation,](https://reader030.vdocuments.site/reader030/viewer/2022040714/5e1a72e62079c464e0745314/html5/thumbnails/22.jpg)
Application to 3 Iowa Bridges
• US 63 Ottumwa
– Cathodic Protection - Arc-sprayed zinc
• IA 192 Council Bluffs• IA 192 Council Bluffs
– Chloride extraction (ECE)
– Cathodic protection - Discrete anode
• I-380 Cedar Rapids
– Cathodic Protection – Zinc-hydrogel sheet
![Page 23: Performance of Corrosion Mitigation Systems in Iowa Bridges · Performance of Corrosion Mitigation Systems in Iowa Bridges Work Performed on Behalf of Iowa Department of Transportation,](https://reader030.vdocuments.site/reader030/viewer/2022040714/5e1a72e62079c464e0745314/html5/thumbnails/23.jpg)
IA 192 Council Bluffs
• Corrosion-induced
deterioration widespread
under expansion joints
• Repaired in 1998• Repaired in 1998
– Conventional repair
– ECE on caps & cols.
– ECE and discrete anodes in
exterior beams
– SealerPhoto from www.vector-corrosion.com
![Page 24: Performance of Corrosion Mitigation Systems in Iowa Bridges · Performance of Corrosion Mitigation Systems in Iowa Bridges Work Performed on Behalf of Iowa Department of Transportation,](https://reader030.vdocuments.site/reader030/viewer/2022040714/5e1a72e62079c464e0745314/html5/thumbnails/24.jpg)
Electrochemical Chloride Extraction (ECE)
![Page 25: Performance of Corrosion Mitigation Systems in Iowa Bridges · Performance of Corrosion Mitigation Systems in Iowa Bridges Work Performed on Behalf of Iowa Department of Transportation,](https://reader030.vdocuments.site/reader030/viewer/2022040714/5e1a72e62079c464e0745314/html5/thumbnails/25.jpg)
ECE and Discrete Anodes
Discrete anodes
Photos from www.vector-corrosion.com
![Page 26: Performance of Corrosion Mitigation Systems in Iowa Bridges · Performance of Corrosion Mitigation Systems in Iowa Bridges Work Performed on Behalf of Iowa Department of Transportation,](https://reader030.vdocuments.site/reader030/viewer/2022040714/5e1a72e62079c464e0745314/html5/thumbnails/26.jpg)
IA 192 Council Bluffs - 2009 Survey
• Visual condition
• Sounding
Half-cell testing• Half-cell testing
• Chloride sampling
• Electrical testing of
discrete anode
performance
![Page 27: Performance of Corrosion Mitigation Systems in Iowa Bridges · Performance of Corrosion Mitigation Systems in Iowa Bridges Work Performed on Behalf of Iowa Department of Transportation,](https://reader030.vdocuments.site/reader030/viewer/2022040714/5e1a72e62079c464e0745314/html5/thumbnails/27.jpg)
IA 192 Council Bluffs - 2009 Survey
Pier 14 West
Delam
![Page 28: Performance of Corrosion Mitigation Systems in Iowa Bridges · Performance of Corrosion Mitigation Systems in Iowa Bridges Work Performed on Behalf of Iowa Department of Transportation,](https://reader030.vdocuments.site/reader030/viewer/2022040714/5e1a72e62079c464e0745314/html5/thumbnails/28.jpg)
IA 192 Council Bluffs –
Chloride in Pier Caps
• Core samples taken
for comparison
with values
reported by
contractor0.400
0.500
0.600
Wa
ter
So
lub
le C
hlo
rid
e
(% b
y w
t)
Pier 3
NE-3 0-1
NE-3 1-2
SW-3 0-1
contractor
0.000
0.100
0.200
0.300
1998 - Before
Treatment
(Vector)
1998 - After
Treatment
(Vector)
2009
(WJE)
Wa
ter
So
lub
le C
hlo
rid
e
(% b
y w
t)
SW-3 0-1
CT= 0.035%
![Page 29: Performance of Corrosion Mitigation Systems in Iowa Bridges · Performance of Corrosion Mitigation Systems in Iowa Bridges Work Performed on Behalf of Iowa Department of Transportation,](https://reader030.vdocuments.site/reader030/viewer/2022040714/5e1a72e62079c464e0745314/html5/thumbnails/29.jpg)
IA 192 Council Bluffs –
Chloride in Pier Caps
0.400
0.500
0.600
Wa
ter
So
lub
le C
hlo
rid
e
(% b
y w
t)
Pier 14
NE-14 0-1
NE-14 1-2
NW-14 0-1
0.000
0.100
0.200
0.300
1998 - Before
Treatment
(Vector)
1998 - After
Treatment
(Vector)
2009
(WJE)
Wa
ter
So
lub
le C
hlo
rid
e
(% b
y w
t)
SE-14 0-1
SE-14 1-2
CT= 0.035%
Threshold
changed?
![Page 30: Performance of Corrosion Mitigation Systems in Iowa Bridges · Performance of Corrosion Mitigation Systems in Iowa Bridges Work Performed on Behalf of Iowa Department of Transportation,](https://reader030.vdocuments.site/reader030/viewer/2022040714/5e1a72e62079c464e0745314/html5/thumbnails/30.jpg)
IA 192 Council Bluffs - 2009 Survey
East Beams at Pier 3 – Discrete AnodesWest Beams at Pier 3 - ECE
![Page 31: Performance of Corrosion Mitigation Systems in Iowa Bridges · Performance of Corrosion Mitigation Systems in Iowa Bridges Work Performed on Behalf of Iowa Department of Transportation,](https://reader030.vdocuments.site/reader030/viewer/2022040714/5e1a72e62079c464e0745314/html5/thumbnails/31.jpg)
IA 192 Council Bluffs –
Discrete Anode Performance
• Test station not functional – Embedded ref. cell
• Current from anode to • Current from anode to
reinforcing bars was
negligible
– Zinc may be consumed
– Minimal potential
• Limited installation
![Page 32: Performance of Corrosion Mitigation Systems in Iowa Bridges · Performance of Corrosion Mitigation Systems in Iowa Bridges Work Performed on Behalf of Iowa Department of Transportation,](https://reader030.vdocuments.site/reader030/viewer/2022040714/5e1a72e62079c464e0745314/html5/thumbnails/32.jpg)
0.400
0.500
0.600
Wa
ter
So
lub
le C
hlo
rid
e
(% b
y w
t)Beam End
C67 0-1
C67 1-2
IA 192 Council Bluffs –
Chloride in Beam Ends
0.000
0.100
0.200
0.300
1998 - Before
Treatment
(Vector)
1998 - After
Treatment
(Vector)
2009
(WJE)
Wa
ter
So
lub
le C
hlo
rid
e
(% b
y w
t) C67 1-2
CT= 0.035%
![Page 33: Performance of Corrosion Mitigation Systems in Iowa Bridges · Performance of Corrosion Mitigation Systems in Iowa Bridges Work Performed on Behalf of Iowa Department of Transportation,](https://reader030.vdocuments.site/reader030/viewer/2022040714/5e1a72e62079c464e0745314/html5/thumbnails/33.jpg)
IA 192 Council Bluffs - Conclusions
• Study limited by imperfect baseline test
information
• Effectiveness of ECE:
– Chloride concentration in pier caps was apparently – Chloride concentration in pier caps was apparently
reduced and has stayed lower than before test
– Corrosion-related damage is growing 11 years after
treatments
• Effectiveness of Discrete Anodes:
– Discrete anode protection limited: Corrosion evident at
protected ends, but not a good test
![Page 34: Performance of Corrosion Mitigation Systems in Iowa Bridges · Performance of Corrosion Mitigation Systems in Iowa Bridges Work Performed on Behalf of Iowa Department of Transportation,](https://reader030.vdocuments.site/reader030/viewer/2022040714/5e1a72e62079c464e0745314/html5/thumbnails/34.jpg)
Application to 3 Iowa Bridges
• US 63 Ottumwa
– Cathodic Protection - Arc-sprayed zinc
• IA 192 Council Bluffs• IA 192 Council Bluffs
– Chloride extraction (ECE)
– Cathodic protection - Discrete anode
• I-380 Cedar Rapids
– Cathodic Protection – Zinc-hydrogel sheet
![Page 35: Performance of Corrosion Mitigation Systems in Iowa Bridges · Performance of Corrosion Mitigation Systems in Iowa Bridges Work Performed on Behalf of Iowa Department of Transportation,](https://reader030.vdocuments.site/reader030/viewer/2022040714/5e1a72e62079c464e0745314/html5/thumbnails/35.jpg)
I-380 Cedar Rapids
• Corrosion of beam ends
at abutments and under
expansion joints
• Repaired in 2000
– Zinc sheet
![Page 36: Performance of Corrosion Mitigation Systems in Iowa Bridges · Performance of Corrosion Mitigation Systems in Iowa Bridges Work Performed on Behalf of Iowa Department of Transportation,](https://reader030.vdocuments.site/reader030/viewer/2022040714/5e1a72e62079c464e0745314/html5/thumbnails/36.jpg)
I- 380 Cedar Rapids - 2009 Survey
• Visual condition
• Sounding
Debonding• Debonding
• Anode evaluation
![Page 37: Performance of Corrosion Mitigation Systems in Iowa Bridges · Performance of Corrosion Mitigation Systems in Iowa Bridges Work Performed on Behalf of Iowa Department of Transportation,](https://reader030.vdocuments.site/reader030/viewer/2022040714/5e1a72e62079c464e0745314/html5/thumbnails/37.jpg)
Northbound Lanes: Not Protected
![Page 38: Performance of Corrosion Mitigation Systems in Iowa Bridges · Performance of Corrosion Mitigation Systems in Iowa Bridges Work Performed on Behalf of Iowa Department of Transportation,](https://reader030.vdocuments.site/reader030/viewer/2022040714/5e1a72e62079c464e0745314/html5/thumbnails/38.jpg)
Southbound Lanes: Zinc-Hydrogel Sheet
Rebar
connectionconnection
![Page 39: Performance of Corrosion Mitigation Systems in Iowa Bridges · Performance of Corrosion Mitigation Systems in Iowa Bridges Work Performed on Behalf of Iowa Department of Transportation,](https://reader030.vdocuments.site/reader030/viewer/2022040714/5e1a72e62079c464e0745314/html5/thumbnails/39.jpg)
I-380 Cedar Rapids –
Condition of beam ends at abutments
LocationArea of Delam.
or Spall (in2)
Number of
Beams with
Damage
Southbound Lanes
(with CP system)815 8
Northbound Lanes
(without CP system)2129 20
![Page 40: Performance of Corrosion Mitigation Systems in Iowa Bridges · Performance of Corrosion Mitigation Systems in Iowa Bridges Work Performed on Behalf of Iowa Department of Transportation,](https://reader030.vdocuments.site/reader030/viewer/2022040714/5e1a72e62079c464e0745314/html5/thumbnails/40.jpg)
I-380 Cedar Rapids - 2009 Survey
![Page 41: Performance of Corrosion Mitigation Systems in Iowa Bridges · Performance of Corrosion Mitigation Systems in Iowa Bridges Work Performed on Behalf of Iowa Department of Transportation,](https://reader030.vdocuments.site/reader030/viewer/2022040714/5e1a72e62079c464e0745314/html5/thumbnails/41.jpg)
I-380 Cedar Rapids - 2009 Survey
![Page 42: Performance of Corrosion Mitigation Systems in Iowa Bridges · Performance of Corrosion Mitigation Systems in Iowa Bridges Work Performed on Behalf of Iowa Department of Transportation,](https://reader030.vdocuments.site/reader030/viewer/2022040714/5e1a72e62079c464e0745314/html5/thumbnails/42.jpg)
I-380 Cedar Rapids - 2009 Survey
Debonded areaDebonded area
(>50%)
![Page 43: Performance of Corrosion Mitigation Systems in Iowa Bridges · Performance of Corrosion Mitigation Systems in Iowa Bridges Work Performed on Behalf of Iowa Department of Transportation,](https://reader030.vdocuments.site/reader030/viewer/2022040714/5e1a72e62079c464e0745314/html5/thumbnails/43.jpg)
I-380 Cedar Rapids - Anode Performance
• Despite
specification
requiring test
stations and stations and
report, stations
were minimal and
vandalized and
report not
available
![Page 44: Performance of Corrosion Mitigation Systems in Iowa Bridges · Performance of Corrosion Mitigation Systems in Iowa Bridges Work Performed on Behalf of Iowa Department of Transportation,](https://reader030.vdocuments.site/reader030/viewer/2022040714/5e1a72e62079c464e0745314/html5/thumbnails/44.jpg)
I-380 Cedar Rapids - 2009 Survey
Zn corrosion product
in debonded area
![Page 45: Performance of Corrosion Mitigation Systems in Iowa Bridges · Performance of Corrosion Mitigation Systems in Iowa Bridges Work Performed on Behalf of Iowa Department of Transportation,](https://reader030.vdocuments.site/reader030/viewer/2022040714/5e1a72e62079c464e0745314/html5/thumbnails/45.jpg)
I-380 Cedar Rapids – Performance
• Current ranged from 0.7
to 4.4 mA/sq m [Design:
10 mA/sq m]Resistor
• For North Abut.:Test sites
Distance
from end of
beam (in.)
Average
depol. after
15 hrs (mV)
6 94
18 151
![Page 46: Performance of Corrosion Mitigation Systems in Iowa Bridges · Performance of Corrosion Mitigation Systems in Iowa Bridges Work Performed on Behalf of Iowa Department of Transportation,](https://reader030.vdocuments.site/reader030/viewer/2022040714/5e1a72e62079c464e0745314/html5/thumbnails/46.jpg)
I-380 Cedar Rapids - Conclusions
• No baseline data
• Zinc sheet debonded in many areas and consumed
at areas of greatest exposureat areas of greatest exposure
• Zinc sheet protecting beam ends
– Depolarization adequate
– Delam. or spalled area in southbound lanes only 40%
of unprotected northbound lanes
![Page 47: Performance of Corrosion Mitigation Systems in Iowa Bridges · Performance of Corrosion Mitigation Systems in Iowa Bridges Work Performed on Behalf of Iowa Department of Transportation,](https://reader030.vdocuments.site/reader030/viewer/2022040714/5e1a72e62079c464e0745314/html5/thumbnails/47.jpg)
Conclusions
• Comparison of system performance in these three
bridges:
System Protection
CP Discrete Anodes Limited (may be poor test)
CP Arc-Spray Zinc Likely but uncertain
CP Zinc Sheet Good
Chloride ExtractionSome protection, may have
extended life
![Page 48: Performance of Corrosion Mitigation Systems in Iowa Bridges · Performance of Corrosion Mitigation Systems in Iowa Bridges Work Performed on Behalf of Iowa Department of Transportation,](https://reader030.vdocuments.site/reader030/viewer/2022040714/5e1a72e62079c464e0745314/html5/thumbnails/48.jpg)
Conclusions
CP systems offer promise to reduce ongoing
corrosion of substructure and superstructure
elements