Field-Trip-Report_11-16-17.pdf

FIELD TRIP REPORT

Eastern Federal Lands Highway Division, Sterling VA.

Page 1 of 2 EFL-FM-HWY-07(07)

Date : Dec 18, 2017

TO :

Rich Pakhchanian, PE Bridge Branch Chief

FROM :

George Choubah, PE Bridge Design Team Leader

THROUGH: OTHER DIVISIONAL PERSONNEL ATTENDING

FHWA: Rich Pakhchanian, and George Choubah NPS: Michael Molling, Andy Otten, Jeffrey Childers, and Robert Cherry

INCLUSIVE DATES From : Nov 16, 2017 To : Nov 16, 2017

ITINERARY AND PURPOSE FOR TRIP

A team from the NPS, FHWA, and three people from the post-tensioning industry visited the Linn Cove Viaduct (Structure # 5140-182P) to investigate the condition of the post-tensioning (PT) system throughout the bridge. The Linn Cove Viaduct PT anchorage grout caps are deteriorated allowing moisture to penetrate the anchorage system. The moisture is causing corrosion of the PT tendons and anchorage hardware. For long term preservation of the anchorage system, tendons and the overall performance of the structure, the anchors and tendons require removal of corrosion, the installation of the new grout caps, and application of elastomeric material over the anchorage system. If not addressed, these deficiencies will lead to serious and extremely costly repairs in the future.

PRINCIPAL CONTACTS

Name Title Agency Telephone

Michael Molling Chief of Maintenance NPS - Blue Ridge Parkway 828-348-3445

Andy Otten Project Specialist NPS - Denver Service Center 828-348-3475

Rich Pakhchanian Bridge Branch Chief FHWA - EFLHD 703-404-6246

ACCOMPLISHMENTS, RESULTS AND RECOMMENDATIONS

1 A visual inspection was performed on the PT anchorages throughout the bridge; hands-on inspection was performed at couple locations to assess the extent of corrosion on the PT anchorage system.

Results/Conclusion:

- Deteriorated grout caps throughout the bridge (temporary cap formers were used) -Cracked elastomeric coating material with rust stains throughout; the elastomeric coating provides protection to the PT anchorage system

- Minor corrosion on the anchorage plates

- Surface corrosion on the PT strands and wedges

- Lifting holes were not filled with grout during the original construction; signs of water seepage from the deck to the inside of the box through these holes

Recommendations:

- Remove existing grout caps throughout the bridge

- Clean PT anchorage system to white metal

- Place new permanent grout caps formers and fill them with grout

- Apply elastomeric coating material over the entire anchorage system

- Fill lifting holes with grout

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FIELD TRIP REPORT

Eastern Federal Lands Highway Division, Sterling VA.

Page 2 of 2 EFL-FM-HWY-07(07)

Date : Dec 18, 2017

Span 4, Bottom Blister: broken off grout cap with corrosion on PT anchorage Span 3, Bottom Blister: Deteriorated grout cap with exposed strands

Span 8, Top Blister: Deteriorated grout cap with exposed strand Span 2, Top Blister: Cracked elastomeric coating material w/rust stains (Typ.)

Span 4, Bottom Blister: Broken off grout; surface rust on strands and wedges Lifting hole not filled with grout; water stain around it (typical condition)