Integrated Buildings & Structures

Hi Everyone,

I have a retrofit project of a 100-year old concrete building which is severely affected by corrosion.  Samples of the concrete showed carbonation has occurred and a water-soluble chloride ion (Cl-) content higher than 1% by weight of cement.  Could you please comment on the efficacy of using surface applied corrosion inhibitor for reducing corrosion rate throughout the building?    I am embedding galvanic anodes at locations with structural repairs.  Most of the building consists of 8” thick walls with one layer of reinforcement in the middle.

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Fernando Martinez EI, A.M.ASCE
Douglas Wood Associates
Coral Gables FL

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Hi, Fernando. We apply coatings (paintwork) for blocking of carbon dioxide access. It can't improve of the mechanical properties, but can to cease carbonization process... As I see, the reinforcement is not for strenght - only as structural element)

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Oleg Mazurkov C.Eng, M.ASCE
Atombudproekt
Kiyv, Ukraine
+380674027029
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Dear Sir,
In this project first of all we need to stop corrosion.Also these structures are load bearing with 8 " thick concrete walls.
Spalling of concrete might have started.The Cathodic protection is best option. after cathodic protection the retrofiring of concrete can be carried out.
Chandrakant 

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Chandrakant Pol A.M.ASCE
Ass Professor
Walchand College of engineering Sangli
Peth Vadgaon MH
91 8275286672
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You do have to first reduce the chloride ion content.  Research products produced by SIKA and Euclid.

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Alan Johnson P.E., S.E., M.ASCE
Proj Engr
Fraser MI
(313) 820-5449
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Original Message:
Sent: 02-23-2017 02:03
From: Chandrakant Pol
Subject: Using surface applied corrosion inhibitor for reducing corrosion rate

Dear Sir,
In this project first of all we need to stop corrosion.Also these structures are load bearing with 8 " thick concrete walls.
Spalling of concrete might have started.The Cathodic protection is best option. after cathodic protection the retrofiring of concrete can be carried out.
Chandrakant 

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Chandrakant Pol A.M.ASCE
Ass Professor
Walchand College of engineering Sangli
Peth Vadgaon MH
91 8275286672
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Fernando:

If the chlorides have already penetrated to the depth of the reinforcing, there is little you can do other than use the galvanic protection.

I found an ASCE paper (http://ascelibrary.org/doi/10.1061/%28ASCE%29MT.1943-5533.0000163) that you may wish to take a look at that talks about surface treatments.  It implies that once the chlorides get in, they are in to stay. 

I have heard of a Sika product FerroGard 908 that is supposed to help in these situations but have never used it.  It may make sense to include it in the repair scheme if it fits within the Owner's budget.  Perhaps the combination of galvanic protection and this Sika project will increase the service life enough to satisfy the Owner.

The Owner will need to adopt a maintenance cycle that repaints the building more often to keep the moisture penetration down after your repairs are complete.

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Andrew Stouppe P.E., S.E., M.ASCE
Struktura Engineers
Kaneohe HI
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Hello Fernando,

I agree with the others that your best option is to remove the chlorides if you can.  There are companies (Vector Corrosion Technologies is one that I know) who can do chloride extraction - I've seen their presentation as it relates to bridge components, and it seems impressive, but I have not used this firsthand.  You might want to contact them to see what their take on your situation is.

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Thomas Pechillo M.ASCE
Transportation Manager
BL Companies, Inc.
Hartford CT
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We have used lithium chloride extraction (w/blankets & electrified grid) for contaminated concrete vertical surfaces on a couple of highway projects with disappointing results. Penetration was less than 3 inches even when extending the duration of treatment. AASHTO and others are looking at the many other reactions (Carbonation, ASR, Sulfating, etc.) that also causes deterioration to the matrix. Preliminary results from embedded pucks seems promising. Hope this helps. 

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Michael Arpino P.E., M.ASCE
Structural Engineer
Federal Highway Adimistration
Cambridge MA
(617)494-2316
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We have successfully used a product MCI2000 series corrosion inhibitor for years. It is manufactured by Cortec, St. Paul MN (651) 429-1100. You will want to speak with Jessi. Their products will penetrate 3-4 when surface applied. If the corrosion is top & bottom, you will have to apply it to both surfaces.

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Harry Kuchma S.E., M.ASCE
Principal, KRW Consulting Group
Chicago IL

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Original Message:
Sent: 02-27-2017 08:23
From: Michael Arpino
Subject: Using surface applied corrosion inhibitor for reducing corrosion rate

We have used lithium chloride extraction (w/blankets & electrified grid) for contaminated concrete vertical surfaces on a couple of highway projects with disappointing results. Penetration was less than 3 inches even when extending the duration of treatment. AASHTO and others are looking at the many other reactions (Carbonation, ASR, Sulfating, etc.) that also causes deterioration to the matrix. Preliminary results from embedded pucks seems promising. Hope this helps. 

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Michael Arpino P.E., M.ASCE
Structural Engineer
Federal Highway Adimistration
Cambridge MA
(617)494-2316
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