18-Attachment D Coating Condition Assessment 2025 Report.pdf

Greg Richards

Coatings Consultant

Prepared for:

Ms. Sandra McCormack Bridge Engineer

TYLin 12802 Tampa Oaks Boulevard

Tampa, Florida 33637 (E): sandra.mccormack@tylin.com

Prepared by:

KTA-Tator, Inc.

145 Enterprise Drive Pittsburgh, PA 15275

(E): grichards@kta.com

(412) 788-1300 www.kta.com

KTA-Tator, Inc.

CO AT IN G CO ND IT IO N ASS E S SM E NT O F

CO LU M BU S DRI V E SWI NG BRI DG E #105504

CO LU M BU S DRI V E O VE R T HE H I L LSB O R OU GH R I V ER IN TAM P A , FLO RI DA

GRR/RSLlmb

JN66077104

February 13, 2025 http://www.kta.com/ i

TABLE OF CONTENTS

Introduction

Summary

Background

Field Investigation

Samples

Laboratory Investigation

Microscopic Examination

Infrared Spectroscopy

Discussion

Recommendations

APPENDICES

1. Field Investigation Photographs

2. Heavy Metals Testing Results

3. Photomicrographs

4. Infrared Spectra

Report Disclaimer:

NOTICE: This report represents the opinion of KTA-TATOR, INC. This report is issued in conformance with generally accepted industry practices. While customary precautions were taken to verify the information gathered and presented is accurate, complete, and technically correct, this report is based on the information, data, time, materials, and/or samples afforded. This report should not be reproduced except in full.

February 13, 2025 Page 1 of 12

TYLIN

Coating Condition Assessment of BN105504 Columbus Drive Swing Bridge

JN66077104

INTRODUCTION

KTA-Tator, Inc. (KTA) conducted a condition assessment of the protective coating system applied to the steel of BN 105504 Columbus Drive Swing Bridge over the Hillsborough River in Tampa, Florida. The services were performed in accordance with the Professional Services Agreement dated June 2, 2023, and

Task Work Order dated November 18th, 2024. Please note that no access was available to the swing span and the determinations are based on the pictures provided by Hillsborough County.

This report provides a summary of the coating condition assessment, results of the field and laboratory investigations, a discussion of the findings and plan notes.

SUMMARY

The existing coatings applied to BN 105504 on the swing span are in poor condition and are not providing consistent corrosion protection and require full removal and replacement of the existing coatings. The existing coatings in the Machinery areas are in good condition and require only spot repairs of rusted areas, The girders, cross frames, bearings and bolted connections are steel. The percent of rust on BN 105504 swing span is SSPC VIS2 Grade 4 3% to 10% in isolated areas particularly on the fasteners. The

Machinery areas are SSPC VIS2 Grade 9 0.01% - 0.03 %. The average Dry Film Thickness was 17-33 mils on upper chords of the pony truss. The average Dry Film Thickness was 12.3-20.4 mils in the Machinery areas.

The system on the swing span consists of 4 layers with a white primer, two coats of grey and a topcoat of grey. The system in the machinery area consists of 3 layers with a dark grey primer, mid coat of white and topcoat of grey. Lead was present in the coatings at a level equivalent to 23.4 – 56.5 ppm, total chromium content was approximately <5.87 – 35.8 ppm. Cadmium content was approximately <2.34 – 2<2.35.

Figure 1 – Photograph of the Truss with corrosion damage.

February 13, 2025 Page 2 of 12

Coating Condition Assessment of BN105504 Columbus Drive Swing Bridge

Figure 2 Machinery Area no corrosion present.

Figure 3 Typical spot corrosion to repair in the machinery areas.

Maintenance painting options include spot repair in areas of rust and corrosion in the machinery areas and a full removal and replacement of the existing coating system on the swing span.

February 13, 2025 Page 3 of 12

Coating Condition Assessment of BN105504 Columbus Drive Swing Bridge

JN66077104

BACKGROUND

Bridge Number 105504 carries Columbus Drive over the Hillsborough River in Tampa, Florida. The bridge was built in 1925 and is 470 feet long and consists of 12 spans with the swing span consisting of structural steel. It has main girders, stringers, floor beams and cross frames. The bridge service environment for

Bridge Number 105504 may best fit the classification of slightly aggressive.

F IELD INVESTIGATION

The field visit was conducted by KTA Coating Consultant Mr. Greg Richards on December 13, 2025. He was accompanied by a representative of the City of Tampa. Access was by walking the top section from the sidewalk and accessing the machine areas by ladder from the manway hatches. No access was provided to the swing span steel. The examination included an evaluation of the degree of rusting, the thickness of the existing coating system (non-destructively). Coating samples were removed to test for heavy metals and general thickness. Photographs were taken to document the observations and are included in Appendix 1.

Visual Examination

The degree of corrosion was evaluated in general accordance with SSPC-VIS 21, “Standard Method for

Evaluating the Degree of Rusting on Painted Steel Surfaces”. The distribution of rust is classified as spot rust, general rust, or pinpoint rust.

Degree of rust is graded based on the percent of surface area exhibiting rust. The grading system is as follows:

Table 1 - Rust Grades for Reporting the Degree of Ruston Painted Steel Surfaces

Rust Grade Percent Rust Rust Grade Percent Rust

10 ≤ 0.01 5 > 1 to 3

9 > 0.01 to 0.03 4 > 3 to 10

8 > 0.03 to 0.1 3 > 10 to 16

7 > 0.1 to 0.3 2 > 16 to 33

6 > 0.3 to 1 1 > 33 to 50

The degree of rusting was found to be General Rust Grade 4 on the swing span and Rust Grade 9 in the machinery areas.

1 SSPC-the Society for Protective Coatings, Pittsburgh, PA. Publication No. 00-08

February 13, 2025 Page 4 of 12

Visual Examination Swing Span

Figure 4 General flaking from former repair area top chord.

Figure 5 General spot corrosion on picket fencing throughout.

February 13, 2025 Page 5 of 12

Figure 6 Inside box mildew and very little corrosion.

Figure 7 Crevice corrosion on main girder.

February 13, 2025 Page 6 of 12

Figure 8 Delamination on the outer chord of the swing span.

Figure 9 Peeling clear coat typical throughout upper chords.

February 13, 2025 Page 7 of 12

Figure 10 Corrosion on outer lower chord throughout the swing span.

Coating Thickness

Non-destructive coating thickness measurements were obtained in general accordance with ASTM2 D

7091, “Standard Practice for Nondestructive Measurement of Dry Film Thickness of Nonmagnetic Coatings

Applied to Ferrous Metals and Nonmagnetic, Nonconductive Coatings Applied to Non-Ferrous Metal”. A

Positector 6000 F1 Type 2 (ferrous) gage was employed, and verification of calibration was periodically performed using manufacturer coating thickness standards. Spot measurements are obtained by taking the average of three gage measurements made within a 12 mm (1⁄2 in.) diameter circle. Table 2 provides a summary of coating thickness on various steel elements.

Table 2 - Summary of Coating Thickness Readings (mils)

Location Average Maximum Minimum

105504 Machine Structural Steel Webs 15 18.6 12.3

105504 Machine Structural Steel Stiffeners 18.4 20.4 14.9

105504 Upper Chords Webs 23.0 33.0 16.8

105504 Upper Chords Lattice 19.0 19.0 19.0

Destructive coating thickness was performed in general accordance with ASTM D 4138, “Standard

Practices for Measurement of Dry Film Thickness of Protective Coating Systems by Destructive, Cross-

Sectioning Means” was employed to determine the number and thickness of each coating using a Tooke

2 ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.

February 13, 2025 Page 8 of 12

Coating Condition Assessment of BN105504 Columbus Drive Swing Bridge

JN66077104

Gage with 2X cutting tip. Tooke Gage examination entails scribing through the coating system with a beveled cutting tool and then examination of the beveled cut through the eyepiece of the gage. The optics of the gage provides magnification and a calibrated reticle for coating thickness measurement of each coat.

It should be noted that adjacent coating layers of the same or similar color may not be differentiated by

Tooke gage examination.

Tooke gage examination determined that the swing span had 4 layers

Table 3 – Summary of Tooke Gage Readings (mils)

Coating Layer Color Thickness (mils)

Primer Gray 5

Mid coat X 2 White 10

Topcoat Grey 5

Adhesion

Coating adhesion was evaluated by the Method A tape test method of ASTM D3359-02 “Standard Methods for Measuring Adhesion by Tape Test”. An “X” is scribed through the coating and ASTM-recommended pressure sensitive tape is then carefully applied to the area of the scribed coating and rapidly pulled away.

After the tape is pulled, the area is examined for removal of coating from the substrate or previous coating.

Adhesion is graded based on the scale provided in the ASTM standard. The scale ranges from 5A "No peeling or removal” to 0A "Removal beyond the area of the X”. Typical ratings of 4A to 5A are considered by KTA to represent good adhesion, 2A to 3A represent fair adhesion, while 0A to 1A represent poor adhesion.

The adhesion of the coating system was rated 4A.

SAMPLES

Two coating samples were removed from the bridge coating system. The samples are identified in the following table.

Table 4 - Coating Samples Removed from

BN 105504 Columbus Drive over the Hillsborough River

Sample Sample Location

KTA-1 105504 West Upper Chord

KTA-2 105504 North Machinery Area

February 13, 2025 Page 9 of 12

Coating Condition Assessment of BN105504 Columbus Drive Swing Bridge

JN66077104

The coating samples were submitted to the KTA laboratory for examination and testing. The results are provided below.

LABORATORY INVESTIGATION

The laboratory investigation consisted of microscopic examination and metals testing. The test methods employed, and results of the investigation are provided below.

Metals Testing

Sample KTA-1 and KTA-2 were tested for lead, cadmium, and chromium in accordance with EPA Method

6010D and EPA 3050B. The testing was performed by Schneider Laboratory, Inc., in Richmond, VA. The results are provided in the following table and the test results report is included in Appendix 2.

Table 5 - Lead, Cadmium, Chromium Content

BN 105504 Columbus Drive over the Hillsborough River

Sample ID Location Lead Cadmium Chromium

KTA-1 West Upper Chord 56.5 PPM <2.35 PPM <5.87 PPM

KTA -2 North Machinery Area 23.4 PPM <2.34 PPM 35.8 PPM

Microscopic Examination

Microscopic examination of the samples was conducted using a Keyence VHX-5000 digital microscope with magnification capabilities to 200X. The samples had three to four coating layers. The table below lists the magnification at which the cross-section was examined, the number of layers observed, the color of the individual layers, and the minimum and maximum thickness of the individual layers, measured in mils. The thicknesses are listed in the table below, “Coating Thickness Measurements”. Photographs taken during the examination are provided in Appendix 3.

Table 6 – Coating Thickness Measurements

Sample Description Magnification Layers Thickness (mils)

Columbus Drive BN105504 Paint Chips West Upper Truss

100X

Four Layers Top - Grey

7.9 – 10.5

Grey 1.5 – 3.1

Grey 1.0 – 2.7

Bottom – White 7.1 – 10.8

Columbus Drive BN105504 Paint Chips Machinery Steel

200X

Three Layers Top - Grey

4.7 – 7.7

White 6.0 – 10.6

Bottom – Dark Grey 6.9 – 15.7

February 13, 2025 Page 10 of 12

Infrared Spectroscopy

Infrared spectroscopic analysis was performed with a Perkin Elmer Spectrum Two Fourier transform infrared spectrometer. The spectra were obtained by combining scrapings with potassium bromide powder

(KBr) and forming into pellets under high pressure. The pellets were then placed in the optical path of the spectrometer and spectra were obtained over range of 4000 to 400 cm-1. Four spectra were obtained and are provided in Appendix 4.

Briefly, the analysis revealed the following:

The scrapings of the white topcoats of Samples KTA-1 through KTA-4 (Spectrum Nos. 1 – 4, respectively) was consistent with a urethane resin. The urethan resin was evidenced by the bands near 1730/1690, 1530, 1465, 1380, 1250, and 1170 cm-1. The spectra also contained titanium dioxide, which was indicated by the broad band between 700 and 500 cm-1. Spectrum Nos 2 through 4 also contained crystalline silica.

The crystalline silica was indicated by the bands near 1100, 800 and 780 cm-1.

D ISCUSSION

The examination of the structural steel members on the swing span exhibited corrosion, flaking, peeling and delaminated areas. The existing coating system is not providing good corrosion protection particularly on the fasteners and edges of beams. The amount of corrosion on the fasteners is extreme and the only option is to remove and replace the existing coating system.

The examination of the structural steel members and machinery in the machine areas exhibited good corrosion protection and only spot repairs are required.

The coating system is a appears to originally have been a zinc rich primer, epoxy mid coat, and a urethane topcoat and urethane clear coat on the outer faces of the swing span steel. In this case only full removal and replacement of the existing coating system is recommended. Due to the amount of active corrosion maintenance painting should be performed soon.

The laboratory analysis has found that the existing coating system contains concentrations of the toxic metals lead, cadmium, and chromium. The presence of these toxic metals in the existing paint film will necessitate the implementation of worker protection and environmental protection controls, in order to comply with federal, state, and local regulations.

RECOMMENDATIONS

Removal and Replacement of the Swing Span Existing Coating System

KTA recommends full removal and replacement:

Remove bulk materials (high film build, wildlife debris) by and power wash as stated below.

February 13, 2025 Page 11 of 12

Coating Condition Assessment of BN105504 Columbus Drive Swing Bridge

JN66077104

Abrasive blast clean to an SSPC-SP 10 degree of cleanliness to produce and anchor profile recommended by the coating manufacturer.

Apply a replacement coating system that can survive and perform well after exposure to a potential flood event and be of a composition that minimizes the undercutting of the system. The FDOT 561

APL for Coating Existing Structures has approved products that meets these conditions.

Spot Repair and Coat the Machinery Room Structural Steel

The degree corrosion in the machinery areas is minimal. The only actions required is to spot repair the rusted areas. The areas should be:

Spot surface preparation to SSPC SP11 Power Tool Cleaning to Bare Metal.

Spot Prime – Organic Zinc Rich Epoxy

Spot mid coat – High Build Epoxy

Spot top coat – Polyurethane

All products are on the FDOT 561 APL Coating Existing Structures.

February 13, 2025 Page 12 of 12

PLAN NOTES

1. PROVIDE A MINIMUM CLASS 2A CONTAINMENT WHEN ABRASIVE BLAST CLEANING. PROVIDE A

MINIMUM CLASS 2W CONTAINMENT DURING WET CLEANING AND WASHING PROCEDURES.

PROVIDE A MINIMUM CLASS 3P CONTAINMENT FOR HAND AND POWER TOOL CLEANING.

2.

SURFACE PREPARATION PER SSPC SP-10 NEAR WHITE METAL BLASTING OR SSPC SP11

POWER TOOL CLEANING TO BARE METAL WITH THE ENGINEERS APPROVAL.

3. USE A FOUR COAT SYSTEM PER FDOT 561 APL. THE SYSTEM SHALL CONSIST OF:

A. ORGANIC ZINC RICH PRIMER

B. HIGH BUILD EPOXY

C. POLYURETHANE TOPCOAT

D. POLYURETHANE CLEAR COAT. LOCATIONS PER PLANS.

4. PROVIDE A SITE-SPECIFIC QC PLAN THAT INCLUDES WRITTEN METHODS TO VERIFY THE

REQUIREMENTS IN THE CONTRACT DOCUMENTS. ACCOMPANY ALL THE FDOT STANDARD

SPECIFICATION SECTION NUMBERS WITH ALL INSPECTION USED FOR VERIFICATION OR

CONTRACT REQUIREMENTS. IN ADDITION, INCLUDE THE FOLLOWING IN THE SITE-SPECIFIC QC

PLAN:

A. COMPANY’S ORGANIZATION CHART DEFINING INDIVIDUAL RESPONSIBILITIES.

B. RECEIPT, DISTRIBUTION, AND REVISIONS OF PROJECT DOCUMENTS.

C. QC STANDARDS AND INSTRUMENTS.

D. PROCEDURES FOR PREPARATION AND COATING OF HARD TO ACCESS AREAS INCLUDING

CONTAINMENT ATTACHMENT POINTS.

E. REPAIR PROCEDURES FOR DEFICIENT OR DEFECTIVE SURFACE PREPARATION AND

COATING APPLICATIONS.

Appendix 1

February 13, 2025 A1 - 1 of 5

TYLin

APPENDIX 1 - JN66077104

PHOTOGRAPHS BN 105504 COLUMBUS DRIVE

Figure 1 – Typical machine areas existing coatings.

Figure 2 – Typical Machine area equipment.

February 13, 2025 A1 - 2 of 5

Figure 3 – Typical Steel Coating in the Machine Areas.

Figure 4 – Delamination on lower chard.

February 13, 2025 A1 - 3 of 5

Figure 5 – Cracking and undercutting on Gusset Plate.

Figure 6 – Fastener corrosion on Lower Chord.

February 13, 2025 A1 - 4 of 5

Figure 7 – Fastener corrosion.

Figure 8 – Fastener corrosion.

February 13, 2025 A1 - 5 of 5

Figure 9 – Fastener Corrosion.

Appendix 2

Appendix 3

February 13, 2025 A3 - 1 of 1

APPENDIX 3 - JN66077104

PHOTOMICROGRAPHS

KTA-1 100X Cross-section

KTA-2 200X Cross-section

Appendix 4

Analyst Administrator

Number of Scans 4

Description TY LIN KTA-1 topcoat, pellet, 66077104

Resolution 4

Creation Date 12/23/2024 4:09:57 PM

SPECTRUM # 1

February 13, 2025 A4 - 1 of 2

Analyst Administrator

Number of Scans 4

Description TY LIN KTA-2 topcoat, pellet, 66077104b

Resolution 4

Creation Date 12/23/2024 4:18:09 PM

SPECTRUM # 2

February 13, 2025 A4 - 2 of 2