To: "brown, michael" ;"crampton, douglas d." ;"santosuosso, brian" ;"schmit, david" ;"warke, robert" From: "steiner, kimberly a." Sent: 2024-02-21 22:04 Received: 2024-02-21 22:04 Importance: Normal Subject: RE: RIDOT Washington Bridge (700) We need a representative through-thickness sample of the corrosion product. The best way to collect it is to take a clean utility knife or similar and remove the corrosion product in chunks into a clean vial or container or piece of paper. It can be in multiple pieces or powdered because we will grind it here anyway. But it need to be the whole depth, so you may need to scrape some off.   I made a video on how to collect corrosion product for lab studies here . A demonstration of what I want you to do starts around 4:58.   Kim   From: Brown, Michael Sent: Wednesday, February 21, 2024 3:11 PM To: Steiner, Kimberly A. ; Crampton, Douglas D. ; Warke, Robert ; Santosuosso, Brian ; Schmit, David Subject: RE: RIDOT Washington Bridge (700)   I would be curious to know how we should sample for this XRD testing (I assume this is not a field method). Is there a protocol of some sort?   Michael   Michael C. Brown, PhD, PE, FACI Associate Principal _________________________________________ Wiss, Janney, Elstner Associates, Inc. Engineers | Architects | Materials Scientists 2941 Fairview Park Dr., Ste. 300, Falls Church, VA 22042 tel 703.641.4601 | direct 703.641.6503 | mobile 434.953.6285 www.wje.com mbrown@wje.com     From: Steiner, Kimberly A. < KSteiner@wje.com > Sent: Wednesday, February 21, 2024 15:19 To: Brown, Michael < MBrown@wje.com >; Crampton, Douglas D. < DCrampton@wje.com >; Warke, Robert < RWarke@wje.com >; Santosuosso, Brian < bsantosuosso@wje.com >; Schmit, David < DSchmit@wje.com > Subject: RE: RIDOT Washington Bridge (700)   Thanks for sending the interesting paper Robert. If interested, I am happy to run XRD on the corrosion product and see how it compares to those in the paper.   Kim   From: Brown, Michael < MBrown@wje.com > Sent: Wednesday, February 21, 2024 1:23 PM To: Crampton, Douglas D. < DCrampton@wje.com >; Warke, Robert < RWarke@wje.com >; Santosuosso, Brian < bsantosuosso@wje.com >; Schmit, David < DSchmit@wje.com >; Steiner, Kimberly A. < KSteiner@wje.com > Subject: RE: RIDOT Washington Bridge (700)   Doug,   Thanks.  This all makes good sense.  I am awaiting the inspection report and may circle back when we have it in hand.   Michael   Michael C. Brown, PhD, PE, FACI Associate Principal _________________________________________ Wiss, Janney, Elstner Associates, Inc. Engineers | Architects | Materials Scientists 2941 Fairview Park Dr., Ste. 300, Falls Church, VA 22042 tel 703.641.4601 | direct 703.641.6503 | mobile 434.953.6285 www.wje.com mbrown@wje.com     From: Crampton, Douglas D. < DCrampton@wje.com > Sent: Wednesday, February 21, 2024 14:20 To: Brown, Michael < MBrown@wje.com >; Warke, Robert < RWarke@wje.com >; Santosuosso, Brian < bsantosuosso@wje.com >; Schmit, David < DSchmit@wje.com >; Steiner, Kimberly A. < KSteiner@wje.com > Subject: RE: RIDOT Washington Bridge (700)   Hi Michael, It looks to be far enough from the coast, but it is over brackish water. The performance will be dependent on the time of wetness/RH and the amount of airborne chlorides. It is high off the water, so it should have good air circulation underneath to promote drying. From what I can tell, it was built in the early to mid-2000’s. At around 20 years old, it should have had enough time to develop a patina, as well as show evidence of improper patina formation, if present. The study we did for Iowa can be found here . We felt that visual inspection of the patina was the best way to determine its condition because it was easy and practical. We tried in-situ chloride testing and the results had quite a bit of scatter and we weren’t confident that the tests were counting the chlorides that were “trapped” during the patina formation. We also took cores to perform lab testing for chlorides, but there were so few tests that we couldn’t really compare the results to anything. Similarly, XRD was performed on a few samples, but there was limited data for comparison to call a patina “good” or “bad”. Perhaps the recent journal paper provided by Robert may help assessing patinas with XRD.   Another weathering steel reference was published by NSBA about a year ago. It helps to summarize good and bad environments for patina development.   I think the best first step is to look at the inspection report to see the overall condition of the patina and if there are any problem areas. After 15 to 20 years of service, good and bad areas should have had plenty of time to form. If there are problem areas, you could consider XRD (if the conclusions of the journal paper sound promising) or set up a test to determine chloride deposition rates (to see if the environment has a potential to create issues). In the end, problem areas should be addressed by washing and monitoring during future inspections. If they continue to worsen, painting may be needed.   I hope this helps. Feel free to call if you would like to discuss further.   Doug   From: Brown, Michael < MBrown@wje.com > Sent: Wednesday, February 21, 2024 12:05 PM To: Crampton, Douglas D. < DCrampton@wje.com >; Warke, Robert < RWarke@wje.com >; Santosuosso, Brian < bsantosuosso@wje.com >; Schmit, David < DSchmit@wje.com >; Steiner, Kimberly A. < KSteiner@wje.com > Subject: RE: RIDOT Washington Bridge (700)   Doug,   We have been engaged to investigate the failure of two PT tie-down rods for longitudinal post-tensioned cantilever beams on an interstate bridge, which they closed to traffic in December.  The bridge is located near the mouth of the Seekonk River into the Providence River close to Narragansett Bay. Our metallurgical assessment noted corrosion-related section loss and chemical spectroscopy of the rust product indicated potential exposure to both deicing salts sea water.    Washington Bridge - Google Maps   In discussing the findings of our investigation with the client this morning, they noted there is a separate parallel structure (age not yet known) that is fabricated with weathering steel. In response to our indication of potential seawater spray exposure on the bridge in our report, they asked what the implications might be for the adjacent weathering steel structure and how it could be evaluated.   I’m happy to discuss details with you at your convenience.   Michael   Michael C. Brown, PhD, PE, FACI Associate Principal _________________________________________ Wiss, Janney, Elstner Associates, Inc. Engineers | Architects | Materials Scientists 2941 Fairview Park Dr., Ste. 300, Falls Church, VA 22042 tel 703.641.4601 | direct 703.641.6503 | mobile 434.953.6285 www.wje.com mbrown@wje.com     From: Crampton, Douglas D. < DCrampton@wje.com > Sent: Wednesday, February 21, 2024 12:52 To: Warke, Robert < RWarke@wje.com >; Santosuosso, Brian < bsantosuosso@wje.com >; Brown, Michael < MBrown@wje.com >; Schmit, David < DSchmit@wje.com >; Steiner, Kimberly A. < KSteiner@wje.com > Subject: RE: RIDOT Washington Bridge (700)   I’m late to the party here. Michael, can you please provide some of the background info?   • How old is the bridge? • What is the chloride exposure? ○ One-time from shipping steel segments on the ocean? ○ Continual from a coastal environment? How far is the bridge from the ocean? • Do we have a rough idea of how the patina looks now? •     Thank you, Doug   From: Warke, Robert < RWarke@wje.com > Sent: Wednesday, February 21, 2024 11:44 AM To: Santosuosso, Brian < bsantosuosso@wje.com >; Brown, Michael < MBrown@wje.com >; Schmit, David < DSchmit@wje.com >; Crampton, Douglas D. < DCrampton@wje.com >; Steiner, Kimberly A. < KSteiner@wje.com > Subject: RE: RIDOT Washington Bridge (700)   While we wait for Doug, it occurred to me that x-ray diffraction (XRD) analysis of the corrosion product might tell us something about its stability, and found this paper where some folks did exactly that.  Interesting work.  XRD would be in Kim’s wheelhouse.   –RWW   From: Warke, Robert Sent: Wednesday, February 21, 2024 11:28 AM To: Santosuosso, Brian < bsantosuosso@wje.com >; Brown, Michael < MBrown@wje.com >; Schmit, David < DSchmit@wje.com >; Crampton, Douglas D. < DCrampton@wje.com >; Steiner, Kimberly A. < KSteiner@wje.com > Subject: RE: RIDOT Washington Bridge (700)   Glad to hear our efforts paid off with positive feedback from RIDOT.    As you know, chloride-rich moisture interferes with the formation of a stable patina on weathering steels, which is why they don’t perform as well in seacoast environments.  If the RIDOT folks are able to scrape off a sample of the corrosion product, which—as you noted—itself would be a bad sign, we could certainly analyze it for evidence of salt exposure.  If they can’t scrape it off, maybe they could extract a few 1-inch cores.  I’m refraining from suggesting how to evaluate patina integrity until we hear from Doug.   I’m including Kim Steiner here, as well, since she always adds wisdom to corrosion conversations.   Robert W. Warke, P.E. Associate Principal WJE  Metallurgy & Applied Mechanics direct 847.753.6349 mobile 832.929.5170   From: Santosuosso, Brian < bsantosuosso@wje.com > Sent: Wednesday, February 21, 2024 11:21 AM To: Brown, Michael < MBrown@wje.com >; Warke, Robert < RWarke@wje.com >; Schmit, David < DSchmit@wje.com >; Crampton, Douglas D. < DCrampton@wje.com > Subject: RE: RIDOT Washington Bridge (700)   Hi Michael- I’ve copied Doug Crampton from Structures II into this conversation. He literally wrote the book on weathering steel patina evaluation.   Doug- Please help, -Brian   Brian J. Santosuosso, SE Principal, Regional Director, and Associate Executive Director of Administration   Wiss, Janney, Elstner Associates, Inc. Engineers | Architects | Materials Scientists 330 Pfingsten Road, Northbrook, IL 60062 tel 847.272.7400 | direct 847.753.7246 | mobile 847.980.8501 www.wje.com bsantosuosso@wje.com     From: Brown, Michael < MBrown@wje.com > Sent: Wednesday, February 21, 2024 8:58 AM To: Warke, Robert < RWarke@wje.com >; Schmit, David < DSchmit@wje.com >; Santosuosso, Brian < bsantosuosso@wje.com > Subject: RIDOT Washington Bridge (700)   Gentlemen,   I just had a meeting with the Director of RIDOT, the Chief Engineer and the State Bridge Engineer.  They were very appreciative and complimentary regarding our report.  Good work!  I walked them through the findings and answered several questions.   With regards to potential seawater spray exposure, they noted that an adjacent structure is composed of weathering steel.  They inquired whether there should be a concern for that structure.  I noted that the primary indication would be if the patina did not look stable but was instead flaking/progressing in corrosion.  I mentioned it might be possible to analyze the patina/corrosion product on the surface to see if similar exposure exists, but that I would confer with you before recommending a specific course of action.  Do you have any thoughts on how we might assess the chemical stability of the weathering steel (beyond simple visual inspection), and whether it would be necessary?  I have requested the most recent inspection report for reference.   Michael   Michael C. Brown, PhD, PE, FACI Associate Principal _________________________________________ Wiss, Janney, Elstner Associates, Inc. Engineers | Architects | Materials Scientists 2941 Fairview Park Dr., Ste. 300, Falls Church, VA 22042 tel 703.641.4601 | direct 703.641.6503 | mobile 434.953.6285 www.wje.com mbrown@wje.com