ISLAND MAPPING OF CHLORIDE DEPOSITION RATEFormed Steel, and 2) Pacific Rim Corrosion Research Project (PRCRP) on the Corrosion of Advanced Metallic Composites, have collected data

UNIVERSITY OF HAWAIICOLLEGE OF ENGINEERING

D

EPARTMENT OF

C

IVIL AND

E

NVIRONMENTAL

E

NGINEERING

ISLAND MAPPING OF CHLORIDE DEPOSITION RATE

Research Report UHM/CEE/06-05

May 2006

Ronald R. Malalis

and

Ian N. Robertson

ii

iii

ABSTRACT

This report outlines development of a program to determine the amount of chlorides

entrained in the atmosphere and thus deposited onto built infrastructure. The project will involve

exposing fifty (50) chloride candles at strategic locations around the island of Oahu. The results

of this research will be used to develop Chloride-Deposition-Rate Maps for the island of Oahu.

This project will aid the Bridge Section of the Hawaii Department of Transportation in the use of

Pontis, an AASHTO bridge and highway management system, and LIFE-365 Corrosion

Prediction model.

Twelve (12) chloride deposition cross-sections containing approximately fifty (50) site

locations were established at strategic locations around the island of Oahu in order to establish

an accurate description of the chloride deposition rate from coastal locations moving inland.

Permission has been requested to mount chloride candle housing units onto State of Hawaii

and City & County of Honolulu street lamp poles at the selected locations. Once approval is

obtained, the chloride candles will be installed and monitored for a one year period.

Two parallel research projects: 1) University of Hawaii’s department of Civil and

Environmental Engineering’s study of the Corrosion of Galvanized Fasteners used in Cold-

Formed Steel, and 2) Pacific Rim Corrosion Research Project (PRCRP) on the Corrosion of

Advanced Metallic Composites, have collected data on the chloride deposition rate at various

locations around the island of Oahu. These data are presented here and will be compared with

the field data collected under the current project.

iv

AKNOWLEDGEMENTS

This report is based on a Master’s Thesis prepared by Ronald Malalis under the

direction of Dr. Ian Robertson. The authors wish to thank Drs. David Ma and Si-Hwan Park for

their assistance in reviewing this report. The authors also wish to thank Paul Santo of the

Hawaii Department of Transportation Bridge Division who was instrumental in the initiation of

this project.

The authors acknowledge the contribution of past chloride deposition data from two

parallel research projects. The University of Hawaii’s Department of Civil and Environmental

Engineering and Larry Williams of the Steel Framing Alliance contributed data from the study of

Corrosion of Galvanized Steel Fasteners used in Cold Formed Steel. Dr. Lloyd Hihara and

George Hawthorn of the Pacific Rim Corrosion Research Program provided data collected from

their study on Corrosion of Advanced Metallic Composites.

This project is funded by a grant from the State of Hawaii Department of Transportation.

This funding is gratefully acknowledged. The findings and opinions in this report are those of

the authors, and do not necessarily reflect those of the funding agency.

v

TABLE OF CONTENTS

CHAPTER 1 INTRODUCTION................................................................................................................................1

1.1 PROJECT OUTLINE ..........................................................................................................................................1 1.2 RESEARCH OBJECTIVES................................................................................................................................2 1.3 PROJECT SCOPE...............................................................................................................................................2

1.3.1 Significant factors affecting the chloride deposition rate ............................................................................3

CHAPTER 2 LITERATURE REVIEW....................................................................................................................5

2.1 IMPACT OF CORROSION ON INFRASTRUCTURE......................................................................................5 2.2 COST OF CORROSION .....................................................................................................................................5 2.3 CORROSION PROCESS....................................................................................................................................6 2.4 ENVIRONMENTAL EFFECTS .........................................................................................................................8 2.5 SOURCES OF CHLORIDES ..............................................................................................................................8

2.5.1 Sources of Chloride can include but are not limited to: ..............................................................................9

CHAPTER 3 REMEDIAL MEASURES.................................................................................................................11

3.1 IMPLEMENTING PONTIS..............................................................................................................................11 3.2 CORROSION PREDICTION MODEL, LIFE-365 ...........................................................................................12 3.3 IMPLEMENTATION AND BENEFITS...........................................................................................................13

CHAPTER 4 SITE SELECTION ............................................................................................................................15

4.1 SITE SELECTION RATIONALE.....................................................................................................................15 4.2 CHLORIDE DEPOSITION CROSS-SECTIONS.............................................................................................16

4.2.1 Preliminary Site Selection..........................................................................................................................18

CHAPTER 5 CHLORIDE MONITORING............................................................................................................23

5.1 WET CANDLE METHOD, ISO 9225:1993(E).................................................................................................23 5.1.1 Sampling Apparatus, Wet Candle ..............................................................................................................23 5.1.2 Exposure Rack ...........................................................................................................................................24

5.2 EQUIPMENT....................................................................................................................................................25 5.2.1 Chloride Test System..................................................................................................................................25 5.2.2 Fastening System .......................................................................................................................................25 5.2.3 Weather Monitoring Station.......................................................................................................................25

5.3 SAMPLING.......................................................................................................................................................26

CHAPTER 6 PRELIMINARY RESULTS..............................................................................................................26

6.1 CORROSION OF GALVANIZED FASTENERS USED IN COLD-FORMED STEEL FRAMING .........................................27

vi

6.1.1 Chloride Deposition Rate ..........................................................................................................................27 6.1.2 Wheeler AAF Site.......................................................................................................................................28 6.1.3 Iroquois Point Coastal Site ........................................................................................................................29 6.1.4 Iroquois Point Inland Site ..........................................................................................................................30 6.1.5 Marine Corps Base Coastal Site ................................................................................................................32 6.1.6 Marine Corps Base Inland Site ..................................................................................................................32 6.1.7 Analysis of Chloride Data..........................................................................................................................33 6.1.8 Wheeler AAF..............................................................................................................................................36 6.1.9 Iroquois Point Coastal and Inland Sites ....................................................................................................36 6.1.10 Marine Corps Base Coastal Site ..............................................................................................................38 6.1.11 Marine Corps Base Inland Site ................................................................................................................41

6.2 PACIFIC RIM CORROSION RESEARCH PROGRAM..................................................................................44 6.2.1 Manoa Valley.............................................................................................................................................45 6.2.2 Waipahu.....................................................................................................................................................46 6.2.3 Ewa Beach Inland ......................................................................................................................................47 6.2.4 Campbell Industrial Park ..........................................................................................................................48 6.2.5 Kahuku.......................................................................................................................................................49 6.2.6 Coconut Island...........................................................................................................................................50

6.3 CONCLUDING OBSERVATIONS..................................................................................................................50 6.3.1 Corrosion of Galvanized Fasteners ...........................................................................................................50 6.3.2 Pacific Rim Corrosion Research Project ...................................................................................................52

vii

Table of Figures

Figure 1.1 Existing and Proposed Chloride Sites from CEE and ME Departments .....................................................4 Figure 2.1 Electrochemical Corrosion Cell ..................................................................................................................7 Figure 4.1 Coastal Conditions on Oahu......................................................................................................................16 Figure 4.2 Typical Chloride Deposition Cross-Section...............................................................................................17 Figure 4.3 Proposed Chloride Cross Sections ............................................................................................................18 Figure 5.1 Sampling Apparatus Assembly...................................................................................................................24 Figure 6.1: Wheeler AAF Chloride Deposition Rates .................................................................................................29 Figure 6.2: Iroquois Point Coastal Chloride Deposition Rates ..................................................................................30 Figure 6.3: Iroquois Point Inland Chloride Deposition Rates ....................................................................................31 Figure 6.4: Marine Corps Base Coastal Chloride Deposition Rates ..........................................................................31 Figure 6.5: Marine Corps Base Inland Chloride Deposition Rates ............................................................................32 Figure 6.6: Chloride Deposition Rates........................................................................................................................33 Figure 6.7: Average Chloride Deposition Rates .........................................................................................................34 Figure 6.8: Comparison of Iroquois Coastal, Iroquois Inland and Wheeler Chloride Deposition Rates ...................35 Figure 6.9: Comparison of Marine Corps Base Coastal vs. Inland Chloride Deposition Rates.................................36 Figure 6.10: Iroquois Point Inland Wind Direction During Period of High Chloride Deposition .............................37 Figure 6.11: Iroquois Point Inland Wind Speed During Period of High Chloride Deposition...................................38 Figure 6.12: Marine Corps Base Coastal Wind Direction During Period of Low Chloride Deposition ....................39 Figure 6.13: Marine Corps Base Coastal Wind Speed During Period of Low Chloride Deposition ..........................39 Figure 6.14: Marine Corps Base Coastal Wind Direction During Period of High Chloride Deposition ...................40 Figure 6.15: Marine Corps Base Coastal Wind Speed During Period of High Chloride Deposition.........................40 Figure 6.16: Marine Corps Base Inland Wind Direction During Period of Low Chloride Deposition ......................42 Figure 6.17: Marine Corps Base Inland Wind Speed During Period of Low Chloride Deposition ............................42 Figure 6.18: Marine Corps Base Inland Wind Direction During Period of High Chloride Deposition .....................43 Figure 6.19: Marine Corps Base Inland Wind Speed During Period of High Chloride Deposition...........................43 Figure 6.20 Existing Site locations of the Pacific Rim Corrosion Research Program................................................44 Figure 6.21 Manoa Valley Chloride Deposition Rates................................................................................................45 Figure 6.22 Waipahu Chloride Deposition Rates........................................................................................................46 Figure 6.23 Ewa Beach Inland Chloride Deposition Rates.........................................................................................47 Figure 6.24 Campbell Industrial Park Chloride Deposition Rates .............................................................................48 Figure 6.25 Kahuku Chloride Deposition Rates..........................................................................................................49 Figure 6.26 Coconut Island Chloride Deposition Rates..............................................................................................50

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Page 1

Chapter 1 INTRODUCTION

1.1 PROJECT OUTLINE This research investigation focuses on the amounts of chloride entrained in the

atmosphere and subsequently deposited on to land and built infrastructure in order to

categorize how corrosive an environment can be. The results of this research will aid the

Bridge Section of the Hawaii Department of Transportation in the use of Pontis1, an

AASHTO bridge and highway management system, and LIFE-365 Corrosion Prediction

model, to manage the State bridge inventory.

This project was initiated on August 1, 2005, by an award from the Research

Branch of the Hawaii Department of Transportation. The project includes a research

effort to monitor the deposition rate of chlorides using the International Organization for

Standardization 9225 (ISO 9225:1992(E)) at representative locations around the island

of Oahu. Inferences will be made regarding the deposition rates for similar locations on

the neighbor islands.

The project has been allotted a two-year duration with various scheduled

deliverables, but due to delays in approval for field instrumentation placement, chloride

deposition monitoring stations have not yet been distributed. In lieu of the chloride

deposition research, reference will be made in this report to data collected during two

research projects of the University of Hawaii’s College of Engineering. These projects

are; 1) Corrosion of Galvanized Fasteners used in Cold-Formed Steel Framing and 2)

Corrosion of Advanced Metallic Composites. Chloride deposition rates were recorded for

both projects as a basis for analyzing corrosion rates due to the presence of chloride

ions.

1 AASHTO BRIDGEWare, Bridge Engineering and Management Solutions, www.aashtoware.org

Page 2

Once approval is obtained for field implementation, fifty chloride monitor stations

will be installed around the island of Oahu. The chloride stations will then be monitored

bi-weekly for a period of one year as a basis for developing chloride deposition maps for

the Island of Oahu.

1.2 RESEARCH OBJECTIVES The object of this research project is to determine and monitor airborne chloride

deposition levels for a one-year duration to subsequently develop chloride-deposition-

rate maps for the island of Oahu. Once generalized chloride-deposition-rate maps have

been established for the island of Oahu, inferences will be made regarding the

deposition rates for similar locations on the neighbor islands.

1.3 PROJECT SCOPE To determine and monitor chloride levels in the atmosphere, approximately fifty

(50) atmospheric chloride candles will be installed at strategic locations around the

island of Oahu to produce a generalized map of the chloride deposition rate. Each of the

fifty sites will be monitored and processed bi-weekly for a duration of one year. This

period will allow for the yearly climatic and coastal changes experienced on Oahu to

provide a generalization of the chloride deposition results.

Selection of the various sites will be based on coastal conditions, prevailing wind

direction, land topography, etc. so as to capture representative cross-sections of

exposure from shoreline to the interior of the island. The chloride candle measurements

will be conducted in accordance with the International Organization for Standardization

9255 (ISO 9225:1992 (E)) standard.

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1.3.1 Significant factors affecting the chloride deposition rate • Proximity to the Ocean

• Topography between ocean and site

• Natural or Man-Made obstructions between ocean and site

• Predominant wind direction – on-shore or off-shore

• Coastal conditions – beach, fringing reef, rocky coastline, cliffs, etc.

• Average wave size – depending on seasonal swells

• Average wind speed and direction

Currently, there are five (5) Chloride test sites located on the Leeward and East

shorelines of Oahu as part of a study on Corrosion of Galvanized Fasteners used in

Cold-Formed Steel Framing. This study was funded by the US Department of Housing

and Urban Development and performed by the Steel Framing Alliance and the

Department of Civil Engineering. Concurrently, the University of Hawaii’s Department of

Mechanical Engineering has initiated a research study on corrosion rates of alloys and

metals and will also be monitoring the chloride deposition rates on Oahu and other

Hawaiian Islands. Figure 1.1 identifies the general locations of the existing and proposed

chloride test sites around the island of Oahu for these two parallel studies.

Page 4

Figure 1.1 Existing and Proposed Chloride Sites from CEE and ME Departments

Page 5

Chapter 2 LITERATURE REVIEW

2.1 IMPACT OF CORROSION ON INFRASTRUCTURE The premature corrosion and deterioration of embedded reinforcing steel in

concrete is primarily due to the penetration of chlorides from deicing salts, groundwater,

or seawater. In the United States alone, billions of dollars is spent each year to repair

and/or to replace infrastructure damage caused by the effects of chloride penetration

(Cady 1984). To put it in another prospective, of the 580,000 bridges in the US, 160,000

are structurally deficient and in need of repair (Cady 1984). This means over 25% of all

the bridges around the U.S. are in need of some form of repair or replacement.

It is widely known that the major initiator of corrosion of reinforcing steel is the

penetration of chlorides through the cover concrete. Therefore, it is obviously important

to be able to quantify the status of deterioration of a reinforced concrete structure during

its lifetime, to assess the need for repair, to assess the performance of protection

mechanisms in existence, and to assess the need for application of protection methods.

By taking into account the necessary life of the structure, together with initial cost versus

maintenance cost considerations, different techniques of corrosion prevention can be

evaluated as to their likely effect on the total life of the structure and their applicability to

different situations.

2.2 COST OF CORROSION According to a Highway Bridge report on the Costs of Corrosion by Yunovich et

al., the dollar impact of corrosion on highway bridges is quit considerable. It states that

the annual direct cost of corrosion for highway bridges is estimated to be $6.43 billion to

$10.15 billion, consisting of $3.79 billion to replace structurally deficient bridges over the

next 10 years, $1.07 billion to $2.93 billion for maintenance and cost of capital for

Page 6

concrete bridge decks, $1.07 billion to $2.93 billion for maintenance and cost of capital

for concrete substructures and superstructures (minus decks), and $0.50 billion for the

maintenance painting cost for steel bridges. This gives an average annual cost of

corrosion of $8.29 billion. Life-cycle analysis estimates indirect costs to the user due to

traffic delays and lost productivity at more than 10 times the direct cost of corrosion. In

addition, it was estimated that employing “best maintenance practices” versus “average

practices” can save 46 percent of the annual corrosion cost of a black steel rebar bridge

deck, or $2,000 per bridge per year.

Yunovich et al. also states that while there is a downward trend in the percentage

of structurally deficient bridges (a decrease from 18 percent to 15 percent between 1995

to 1999), the costs to replace aging bridges increased by 12 percent during the same

period. In addition, there has been a significant increase in the required maintenance of

the aging bridges. Although the vast majority of the approximately 108,000 pre-stressed

concrete bridges have been built since 1960, many of these bridges will require

maintenance in the next 10 to 30 years. Therefore, significant maintenance, repair,

rehabilitation, and replacement activities for the nation’s highway bridge infrastructure

are foreseen over the next few decades before current construction practices begin to

reverse the trend.

2.3 CORROSION PROCESS Chloride-induced corrosion or reinforcing steel in concrete structures is a well-

known problem that has been extensively researched and studied since the early 1960’s

(Gibson 1987). ASTM (G 15) defines corrosion as “the chemical or electrochemical

reaction between a material, usually a metal, and its environment that produces a

deterioration of the material and its properties. Although much advancement in

Page 7

technology and research capabilities has been made, the basic principles of chloride-

induced corrosion stay the same.

Chloride-induced electrochemical corrosion is traced to the electrolytic cell, which

must first be established in order for corrosion to occur (Gibson 1987). The three

components that make up these electrolytic cells are: the anode, the cathode, and the

electrolyte as seen in Figure 2.1. Corrosion in steel requires a threshold concentration of

the chloride ion to initiate corrosion; oxygen and moisture then acts as the electrolyte.

Figure 2.1 Electrochemical Corrosion Cell

Page 8

2.4 ENVIRONMENTAL EFFECTS Environmental factors that affect corrosion include temperature, humidity, and

the extent of exposure. Higher temperatures generally increase the rate of corrosion

while colder temperatures slow down the rate of corrosion. The amount of moisture

available and in contact with the material is also a key factor to the rate of corrosion

because water serves as an electrolyte. In dry regions, corrosion may be slow compared

to regions with above-average precipitation.

Exposure is important in assessing corrosion on a single structural member.

Areas exposed to the wind or sun where drying occurs quickly and frequently are less

prone to corrosion than sheltered areas where water or moisture can remain in contact

with the material.

Impurities (such as chlorides) make water a more efficient electrolyte and

accelerate the corrosion process. Because of this, structures in coastal areas – or those

exposed to deicing salts – will corrode faster that structures not exposed to salts.

Studies have shown corrosion rates up to 2.75 times higher when chloride is present

than when it is not.

2.5 SOURCES OF CHLORIDES Research has shown that corrosion of steel in concrete accelerates at a far

greater rate when chloride-ions are present. Chlorides are made present through both

the natural environment and the means and methods of mankind’s everyday living. Most

chlorides deposited on to the land, unfortunately, are unavoidable and will eventually

come into contact with metals, structural steel and concrete reinforcement. Below are a

few examples of chloride sources produced by both nature and mankind.

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2.5.1 Sources of Chloride can include but are not limited to: • Exposure to sea water

• Salts used for de-Icing

• Salt spray from the ocean

• Sulphates from industrial sources

• Acidic rain

Page 10

Page 11

Chapter 3 REMEDIAL MEASURES Corrosion damage can often be avoided through the use of corrosion protection

systems such as low-permeability (high-performance) concretes, corrosion-inhibiting

admixtures, epoxy-coated steel reinforcement, corrosion-resistant steel or non-ferrous

reinforcement, application of waterproofing membranes or sealants, cathodic protection,

or combinations of the above methods and materials. Each of these strategies has

scientific methods and means with expected costs. The challenge is to select the proper

combination of protection methods, at an acceptable cost, to achieve the desired result.

3.1 IMPLEMENTING PONTIS According to the Hawaii Department of Transportation (DOT), their mission is to

facilitate the rapid, safe, and economical movement of people and goods in the State of

Hawaii by providing and operating transportation facilities. They are also responsible for

the planning, design, construction, operation and maintenance of State facilities in all

modes of transportation: air, water, and land. At present, the Hawaii DOT has jurisdiction

over the following facilities: Eleven (11) airports; three (3) general aviation airports;

seven (7) deep-draft harbors; three (3) medium draft harbors and 2,450 miles of

highways2.

In order to keep up with the maintenance and repairs for their wide range of

transportation facilities, the Hawaii DOT plans to implement Pontis, an AASHTO bridge

management system, to manage the State bridge inventory. However, in order to predict

the likely onset of corrosion in both existing and new bridges, the Hawaii DOT Bridge

Section is utilizing a recently developed LIFE-365 Corrosion Prediction model.

2 State of Hawaii Department of Transportation, www.hawaii.gov/dot/about/htm

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LIFE-365 considers numerous variables including the concrete material

variables, the concrete material properties, use of admixtures and reinforcement coating,

concrete cover thickness, and environmental exposure conditions. The most important

environmental conditions are the ambient temperature and the Surface-Chloride-

Concentration Profile. This profile indicates the rate at which chlorides accumulate on

the surface of the concrete.

No information is currently available regarding the rate of chloride accumulation

at various locations in Hawaii. This variable has a significant effect on the time to onset

of corrosion and will greatly affect the output from the LIFE-365 computer model.

Inaccurate predictions can lead to expensive mismanagement of the transportation

infrastructure. If onset of corrosion can be predicted more accurately, relatively

inexpensive remedial measures can be implemented so as to avoid more expensive

repairs once concrete cracking and spalling occur.

3.2 CORROSION PREDICTION MODEL, LIFE-365 LIFE-365 is a standardized service life and life cycle cost model developed under

the American Concrete Institute's Strategic Development Council. This program

calculates the service life and life cycle costs of concrete structures exposed to different

environmental and chemical influences.

LIFE-365 incorporates chloride threshold values for calcium nitrite and butyl

oleate plus amine (OCI), and assumes a five-year window from the initiation of corrosion

to first repair based on the government's Strategic Highway Research Program (SHRP).

When modeling the use of OCI, Life-365 model reduces chloride diffusivity by 10

percent3.

3 AASHTO Innovative Highway Technologies, http://leadstates.transportation.org/hpc/transition_plan_present.stm

Page 13

3.3 IMPLEMENTATION AND BENEFITS The advantage of incorporating LIFE-365 with Pontis will now provide designers

and engineers a prediction of onset of corrosion and the time for corrosion to reach an

unacceptable level. It can then estimate total costs over the entire design life of the

structure, including initial construction costs and predicted repair costs. There are

currently numerous strategies available for increasing the service life of reinforced

structures exposed to chloride, some of these include:

• Low permeability (high-performance) concrete

• Chemical corrosion inhibitors

• Protective coatings on steel reinforcement (i.e. epoxy coating or galvanizing)

• Corrosion-resistant steel

• Fiber reinforcement

• Waterproofing membranes or sealants

• Cathodic protection

LIFE-365, a Life Cycle Cost Analysis (LCCA) program, is being used more and

more frequently to provide the means of computing total costs over the entire design life

of a structure. Both initial construction costs and predicted future repair costs are

included in the analysis. Therefore, although the implementation of a protection strategy

may increase initial costs, it may still reduce life cycle costs by reducing the extent and

frequency of future repairs.

Page 14

Page 15

Chapter 4 SITE SELECTION

4.1 SITE SELECTION RATIONALE Twelve chloride deposition cross-sections proposed for the island of Oahu were

selected based on research of land topography and coastal conditions. Primary factors

considered in cross-section analysis included: 1) Land Topography (Hills, Ridges,

Valleys, Plains, etc.) 2) Proximity to Ocean and 3) Natural and/or Man-Made

Obstructions (Buildings, Bridges, Housing, Industrial Zones, etc.) With an island of

varying land formations and coastal and sea conditions; developing cross sections would

enable the amount of site locations to be minimized and generalize chloride deposition

conditions of similar locations around the island.

Figure 4.1 indicates the coastal conditions (i.e. Beach, Stream, Fringing Reef,

Barrier Reef, etc.) and the cross sections selected based on varying land formations and

coastal and sea conditions. A majority of cross sections were chosen in the regions of

Leeward Oahu, Central Oahu, Honolulu, and East Oahu due to higher populations and

land development. Cross-sections on the West, North, and Northeast facing shores are

minimized due to reoccurring coastal and sea conditions and land formations. Inferences

to chloride deposition rates will be made in these areas.

Page 16

Figure 4.1 Coastal Conditions on Oahu

4.2 CHLORIDE DEPOSITION CROSS-SECTIONS Chloride deposition cross-sections based on land topography and coastal

conditions will indicate the changing levels of chloride deposition from shoreline, moving

further inland. Figure 4.2 depicts a typical chloride deposition cross-section from

shoreline, moving inland, and up on to a hill or mountain ridge. Cross sections will vary

in distances from the shoreline and changes in height elevations. All cross-sections will

be dependent on natural and/or man-made obstructions and obstacles including hills

and valleys, buildings and homes.

Page 17

Figure 4.2 Typical Chloride Deposition Cross-Section

Once chloride deposition cross-sections were established, city and state street

lamp poles within the prospective cross-sections were selected to act as a support for

the chloride test specimen housing units. The housing units will be mounted directly onto

the street lamp poles for support. Street lamp poles were chosen due to their abundance

in availability and intended to mount each specimen housing units at heights away from

vandals and curious children.

Primary considerations for street lamp pole selection are 1) to be free of traffic

lights and street signs 2) clear of any obstructions that may cause blockage to the

environment and 3) sufficiently accessible and without hazard from oncoming traffic. In

theory, this would allow for a better and more accurate indication of the levels of chloride

deposition. Figure 4.3 indicates twelve proposed chloride-deposition cross-sections at

various locations around the island of Oahu.

• With Reef

• Without Reef

• Sandy Shore

• Rocky Shore • Low Roadway

• High Roadway

• Open Terrain

• Obstructions

• Flat Terrain

• Mountainous

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Figure 4.3 Proposed Chloride Cross Sections

4.2.1 Preliminary Site Selection Twelve (12) cross sections were chosen at specific locations around the island of

Oahu where chloride deposition rates will be monitored for a period of one year. Each

cross-section will contain four to six chloride monitoring systems, which have been

selected using the above criteria’s and guidelines. Table 1 is a listing of all street lamp

pole locations chosen for the proposed chloride monitoring systems at this phase of the

research project. Cross-sections, site and address locations, GPS, and elevations

describe each of the street lamp pole locations below. Complete maps and picture

diagrams of the pole locations are provided in the Appendix.

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Table 1 Site Locations by Cross-Section, Address, GPS, and Height Elevation

SITE ADDRESS POLE # GPS ELEV. (ft)

N W

CROSS-SECTION 1: EWA BEACH

1 91-471 Fort Weaver Rd. 124 N150 21-18-45.2 158-00-15.7 37.1

2 Ewa By Gentry / Iroquois Point Rd. 110 N400 II 21-20-10.7 158-01-10.1 72

3 Fort Weaver Rd / Laulaunui St. 93 B 410783 BII 21-22-9.2 158-01-33.2 104.8

4 94-305 Kupuna Lp. 466 36-3866 A2 II 21-23-12.5 158-02-1.1 300

CROSS-SECTION 2: KAPOLEI

1 91-290 Kalaeloa Blvd. 2 M107 AS 21-18-48.3 158-05-59.0 22.6

2 91-140 Kaomi Loop 20 848 21-28-5.6 158-06-36.6 36.4

3 2170 Lauwiliwili St. 22 M101 14 21-19-6.1 158-05-33.1 90.8

4 91-5020 Kapolei Parkway 18 M98 D2 21-19-48 158-04-3.5 110

5 599 Farington Hwy 25 389735 S2 21-20-26.4 158-04-29.2 145.6

6 92-577 Makakilo Dr. 16X M09 21-20-51.4 158-04-52.6 400

7 92-6031 Nemo St. 20 3307 21-21-40.5 158-04-41.6 788

CROSS-SECTION 3: WEST OAHU

1 Kaukamana St. & Farrington Hwy 21-25-26.9 158-10-42.1 75

2 87-226 Halemaluhia Pl. 29 29I 21-25-28 158-10-29.8 62

3 85-043 Waianae Valley Rd. 21-26-32 158-11-17.6 42

4 85-285 Waianae Valley Rd. 18 28 286 21-20-51.4 158-04-52.6 103

CROSS-SECTION 4: NORTH SHORE

To Be Determined

CROSS-SECTION 5: AIEA

To Be Determined

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N W

CROSS-SECTION 6: PEARL CITY

1 Lehua Community Park 21-23-17.9 157-58-20.9 49

2 900 Kamehameha Hwy 14 21-20-51.4 158-04-52.6 108

3 864 Hoomoana St. 21-24-21.8 157-57-47.7 247

4 2130 Ho'oki'eki'e St. 21-24-54.1 157-57-21.9 423

CROSS-SECTION 7: HONOLULU

To Be Determined

CROSS-SECTION 8: WAILUPE

1 5041 Kalanianaole Hwy N: 21° 16' 35" W: 157° 45' 36.5"

2 800 West Hind Drive N: 21° 16' 45" W: 157° 45' 20" 65

3 5006 Poola St. 74 66 N: 21° 16' 38" W: 157° 45' 44"

4 920 Hind Uka St. 52 439 N: 21° 17' 34" W: 157° 45' 17" 125

5 5311 Poola St. 74 20 N: 21° 16' 56" W: 157° 45' 33" 432

CROSS-SECTION 9: HAWAII KAI

1 8270 Kalanianaole Hwy N: 21° 17' 0" W: 157° 43' 4" 47

Maunalua Bay

2 7120 Wailua St. 42 305X N: 21° 17' 19" W: 157° 41' 58" 54

Over Bridge

3 1320 Kamehame St. 73 459 N: 21° 18' 22" W: 157° 40' 45" 722

4 1039 Hoa St. 73 479 N: 21° 18' 9" W: 157° 40' 43" 650

5 440 Kealahou St. N: 21° 17' 42" W: 157° 40' 24" 157

Koko Crater Botanical Garden

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N W

6 8720 Kalanianaole Hwy 90 I N: 21° 17' 27" W: 157° 39' 54" 59

Front of Beach

7 Makapu'u Beach N: 21° 18' 49" W: 157° 39' 54" 86

CROSS-SECTION 10: KAILUA

1 526 Kawailoa Rd. (Kailua Beach Park) No Number 21-23-50 157-43-36.7 80

2 Intersection of Ku'ulei & Kailua Rd. Sign Damaged 21-23-41 157-44-35.6 90

3 618 Hanalei Pl. 6 37 21-23-17.6 157-45-2.0 120

4 Kailua Rd. & Castle Hospital 55 400711 L II 21-22-52.6 157-45-19.8 171

CROSS-SECTION 11: KANEOHE

1 46-112 Nahiku St. Sign Damaged 21-25-23.7 157-48-08 57

2 46-170 Haiku Rd. 31 517 N150 II 21-25-11.2 157-48-28 175.5

3 46-416 Kuneki St. 31 240 21-24-37 157-49-6.4 304.3

4 46-484 Kuneki St. Sign Damaged 21-24-31.9 157-49-17.8 357.1

CROSS-SECTION 12: LAI'E / KAHUKU

To Be Determined

Page 22

Page 23

Chapter 5 CHLORIDE MONITORING

5.1 WET CANDLE METHOD, ISO 9225:1993(E) A rain-protected wet textile surface (wick), with a known area, is exposed for a

specified duration. The amount of chloride deposited is determined by chemical analysis.

From the results of this analysis the chloride deposition rate is calculated, expressed in

milligrams per square meter day [mg/(m2⋅d)].

5.1.1 Sampling Apparatus, Wet Candle

The wet candle is formed of a wick inserted into a bottle. The wick consists of a

central core of about 25 mm in diameter made of inert material (polyethylene). This

material is stretched and/or wound to form a double layer of tubular surgical gauze or a

band of surgical gauze. The surface of the wick exposed to the atmosphere shall be

about 100 cm2, which corresponds to a wick length of about 120 mm. The exposed area

shall be accurately known.

One end of the wick is inserted into a rubber stopper. The stopper has two

additional holes through which the free ends of the gauze pass (if tubular gauze is used,

the lower end is cut along the length of the gauze until about 120 mm is left). The edges

of the three holes are shaped into a funnel so that liquid running down the gauze drains

through the stopper. The free ends of the gauze must be long enough to reach the

bottom of the bottle.

The stopper is inserted into the neck of a bottle of polyethylene or another inert

material, with a volume of about 500 ml. The bottle initially contains 200 to 300 ml of

distilled water.

Page 24

5.1.2 Exposure Rack

The wet candle is exposed on a rack under the center of a roof as shown in

figure 5.1. The roof should be a square of 500 mm side, inert and opaque. The candle

should be attached so that the distance from the roof to the top of the wick is 200 mm

and so that it is centered below the roof. The distance between the bottle and ground

level should be at least one (1) meter. The candle should be exposed towards the sea or

other chloride source.

Figure 5.1 Sampling Apparatus Assembly

Page 25

5.2 EQUIPMENT 5.2.1 Chloride Test System

The CL-2000 Chloride Test System by James Instruments, Inc., Non Destructive

Testing Systems, will be used in measuring the chloride content of each of the test

specimens. The CL Test System determines the total content (or more precisely the acid

soluble content) of chlorides entrained in the sample solution. A calibrated electrode,

with an integral temperature sensor, is inserted into the solution and the electrochemical

reaction measured. The instrument converts the voltage generated by the chloride

concentration and applies the temperature correction. The percentage of chlorides, or

lbs of chloride per cu yd, is displayed directly on an LCD readout.

5.2.2 Fastening System Half inch stainless steel banding straps with ½ inch stainless steel buckles will be

used to attach members of the sampling housing units to the designated street lamp

poles. Currently the City & County and State of Hawaii implements the use of stainless

steel banding straps when attaching street signs and monitoring systems to existing

street lamp poles. This allows for a prolonged exposure to the environment before the

onset of corrosion. Adjustable plastic ties are used to fasten the chloride candle in place.

5.2.3 Weather Monitoring Station A weather monitoring system will be installed at each of the twelve cross-

sections in order to accurately correlate the amount of chloride deposition with the

changing weather patterns experienced throughout the year.

Each system will consist of a Measurement and Control Module (Data Logger),

Wind Sentry for wind speed and direction, and a Temperature and Relative Humidity

Probe. At final installation, the systems will be programmed to record a data sample at

Page 26

every one-second then averaged at every 15 minutes. A final record will be stored within

the system for retrieval and analysis.

5.3 SAMPLING Install the prefabricated candle at the test location and carry out the following steps:

a) adjust the length of the exposed part of the wick to the desired value;

b) remove the stopper and wick form the bottle, wash the free ends of the gauze

and the bottle with distilled water;

c) place 200 to 300 ml of distilled water in the bottle;

d) reassemble the wick and bottle;

e) place the candle in the exposed position according to figure 5.1.

The distilled water should be changed at bi-weekly intervals as follows:

• loosen the stopper in the bottle;

• place the wick in the remaining liquid in the bottle;

• place a new stopper in the bottle for transport to the UH laboratory for testing;

• place a new bottle of fresh distilled water, with stopper and wick in the holder;

Mark the bottle removed from the site with the test site name, location and dates of

exposure and removal. The solution in the bottle is ready for analysis.

Chapter 6 Preliminary Results Two projects are referenced in the following chapter. The first research project

referenced is the Corrosion of Galvanized Fasteners used in Cold-Formed Steel

Framing, performed by Dr. Ian Robertson of the University of Hawaii’s Department of

Civil and Environmental Engineering and Larry Williams of Steel Framing Alliance in

Page 27

Washington, D.C. The second project conducted by L.H. Hihara and G.A. Hawthorn of

the Pacific Rim Corrosion Research Program (PRCRP) provides data of the chloride

deposition rates over the past three years, which have been collected from six sites at

various locations around Oahu. The two research projects will provide preliminary results

of the chloride deposition rates to be expected on the island of Oahu.

6.1 Corrosion of Galvanized Fasteners used in Cold-Formed Steel Framing

A study performed in 2004 monitored the Corrosion of Galvanized Fasteners

used in Cold-Formed Steel (CFS) Framing. The principal investigators for this research

project were Dr. Ian Robertson of the Department of Civil and Environmental

Engineering at the University of Hawaii and Larry Williams of Steel Framing Alliance in

Washington. Co-Investigators were Don Moody and Jay Larson.

A large portion of monitoring the corrosion rate of galvanized fasteners used in

cold-formed steel framing was to also monitor the chloride deposition rate at each of the

five test sites. The five test sites include: 1) Wheeler AAF 2) Iroquois Point Coastal 3)

Iroquois Point Inland 4) Marine Corps Base Coastal and 5) Marine Corps Base Inland.

Each of the five test sites included a chloride candle, exposed for an average duration of

two weeks, and a full weather station collecting data at every one-second intervals.

Chloride deposition rates were collected for a period of six months.

The data presented here is based on the final report of Corrosion of Galvanized

Fasteners used in Cold-Formed Steel Framing by Dr. Ian Robertson and Larry Williams

presented in 2004.

6.1.1 Chloride Deposition Rate Chloride candles have been used at each of the field enclosures to determine

chloride deposition rates over a 6 month period. Each candle was exposed for an

Page 28

average duration of two weeks at a time. When a sample was recovered from the field,

purified water was added to the field sample to produce 400 mL of solution. A 100mL

sample of the diluted solution was then analyzed for its molar chloride concentration

based on the known level of purified water in the flask. These tests were performed

using an ion-selective electrode in the Corrosion Laboratory of the Mechanical

Engineering Department at the University of Hawaii. Based on the exposed area of the

candle wick, the measured chloride concentration is converted to a chloride deposition

rate in mg/m2/day. This represents the average deposition rate during the candle

exposure period.

The purified water used in these monitoring stations was obtained through

reverse osmosis, which is not as pure as distilled water. Subsequent to completion of

the CFS field monitoring study, it was determined that the reverse osmosis water may

have contained some residual chloride content at the start of each candle exposure

period. The results from this study will therefore tend to be higher than reality, and will

consequently not be incorporated in the data used to prepare the final mapping product.

These results do, however, provide useful information regarding chloride deposition

variability and the affect of climatic conditions.

6.1.2 Wheeler AAF Site Chloride deposition rates for the Wheeler AAF site are shown in Figure 6.1: .

Chloride deposition rates vary from 80-580 mg/m2/day range. The highest rate was

recorded during the December 5-11, 2003 period at 581 mg/m2/day. The lowest rate was

80 mg/m2/day, during the January 5 to February 3, 2004 period.

Page 29

0

500

1000

1500

2000

2500

3000

Chl

orid

e D

epos

ition

(mg/

m2/

day)

8/18/20

03 - 8/26

/2003

9/4/200

3 - 9/23/2

003

9/23/20

03 - 9/30

/2003

10/8/20

03 - 10/1

7/2003

10/17/2003

- 10/31/2

003

10/31/2003

- 11/14/2

003

11/14/2003

- 12/05/2

003

12/5/20

03 - 12/1

1/2003

12/11/2003

- 1/05/2004

1/5/200

4 - 2/03

/2004

2/28/20

04 - 3

/22/2004

Chloride Deposition Rate

Figure 6.1: Wheeler AAF Chloride Deposition Rates

6.1.3 Iroquois Point Coastal Site Chloride deposition rates for the Iroquois Point coastal site are shown in Figure

6.2. The highest rate was recorded during the December 5-11, 2003 period at 516

mg/m2/day. Wheeler AAF experienced the same peak period as the Iroquois Point

coastal site. The lowest rate was 167 mg/m2/day during the February 3-28, 2004 period.

Page 30

0

500

1000

1500

2000

2500

3000

Chl

orid

e D

epos

ition

(mg/

m2/

day)

8/13/20

03 - 8

/21/2003

8/21/20

03 - 8

/29/2003

8/29/20

03 - 9/04

/2003

9/30/20

03 - 10/0

8/2003

10/8/20

03 - 10/1

7/2003

10/17/2003

- 10/31/2

003

10/31/2003

- 11/14/2

003

11/14/2003

- 12/05/2

003

12/5/20

03 - 12/1

1/2003

12/11/2003

- 1/05/2004

1/5/200

4 - 1/19

/2004

1/19/20

04 - 2/03

/2004

2/3/200

4 - 2/28/2

004


Figure 6.2: Iroquois Point Coastal Chloride Deposition Rates

6.1.4 Iroquois Point Inland Site Chloride deposition rates for the Iroquois Point inland site are shown in Figure

6.3. The highest rate was recorded during the December 5-11 period at 669 mg/m2/day.

Iroquois Point inland experienced the same peak period as the Iroquois Point coastal

and the Wheeler AAF site. The lowest rate was 105 mg/m2/day, during the November 14

to December 5, 2004 period.

Page 31

0

500

1000

1500

2000

2500

3000

Chl

orid

e D

epos

ition

(mg/

m2/

day)

8/21/20

03 - 8

/29/2003

8/29/20

03 - 9/04

/2003

9/30/20

03 - 10/0

8/2003

10/8/20

03 - 10/1

7/2003

10/17/2003

- 10/31/2

003

10/31/2003

- 11/14/2

003

11/14/2003

- 12/05/2

003

12/5/20

03 - 12/1

1/2003

12/11/2003

- 1/05/2004

1/5/200

4 - 1/19

/2004

1/19/20

04 - 2/03

/2004

2/3/200

4 - 2/28/2

004

2/28/20

04 - 3/18

/2004


Figure 6.3: Iroquois Point Inland Chloride Deposition Rates

0

500

1000

1500

2000

2500

3000

Chl

orid

e D

epos

ition

(mg/

m2/

day)

8/12/20

03 - 8

/21/2003

8/21/20

03 - 8/26

/2003

8/26/20

03 - 9/04

/2003

9/23/20

03 - 9/30

/2003

9/30/20

03 - 10/1

0/2003

11/11/2003

- 11/26/2

003

11/26/2003

-12/1

8/2003

12/18/2003

- 1/13/2004

2/3/200

4 - 3/11/2

004


Figure 6.4: Marine Corps Base Coastal Chloride Deposition Rates

Page 32

6.1.5 Marine Corps Base Coastal Site Chloride deposition rates for the Marine Corps Base coastal site are shown in

Figure 6.4. Chloride deposition rates for Marine Corps Base coastal fall within the 216-

2883 mg/m2/day range, a significant increase over deposition rates for Wheeler AAF and

Iroquois Point sites. The highest rate was seen during the November 26 to December 18

period at 2883 mg/m2/day. The lowest rate was 216 mg/m2/day, during the December

18, 2003 to January 13, 2004 period.

6.1.6 Marine Corps Base Inland Site Chloride deposition rates for the Marine Corps Base inland site are shown in

Figure 6.5. Chloride deposition rates for Marine Corps Base Inland fall within the 165-

768 mg/m2/day range, a significant decrease from deposition rates for the coastal site.

The highest rate was seen during the November 26 to December 18 period at 768

mg/m2/day, less than one third the rate seen at the coastal site for the same period.

0

500

1000

1500

2000

2500

3000

Chl

orid

e D

epos

ition

(mg/

m2/

day)

8/12/20

03 - 8

/21/2003

8/21/20

03 - 8/26

/2003

8/26/20

03 - 9/04

/2003

9/23/20

03 - 9/30

/2003

9/30/20

03 - 10/1

0/2003

10/31/2003

- 11/11/2

003

11/26/2003

-12/1

8/2003

12/18/2003

- 1/13/2004

1/13/20

04 - 2/03

/2004

2/3/200

4 - 3/11/2

004


Figure 6.5: Marine Corps Base Inland Chloride Deposition Rates

Page 33

6.1.7 Analysis of Chloride Data Figure 6.6 shows a comparison of the chloride deposition data collected from

each of the five field sites. The chloride deposition rates at the same site may vary

widely, depending on various weather conditions. The average chloride deposition rate

at each enclosure is shown in Figure 6.7. The Marine Corps Base coastal site

experienced deposition rates of more than four times the deposition rates of the other

four sites, where the average deposition rates are relatively similar.

Wheeler AAFIriquois Inland

Iriquois CoastalMCBH Inland

MCBH Coastal0

500

1000

1500

2000

2500

3000

Chl

orid

e D

epos

ition

Rat

e (m

g/m

2 /day

)

Chloride Deposition Rates

Figure 6.6: Chloride Deposition Rates

Page 34

0

200

400

600

800

1000

1200

1400

1600C

hlor

ide

Dep

ositi

on R

ate

(mg/

m2 /d

ay)

MCBH Coastal MCBH Inland Iroquois Coastal Iroquois Inland Wheeler

Location

Average Chloride Deposition Rates

Figure 6.7: Average Chloride Deposition Rates

Wheeler AAF and Iroquois Point sites experienced similar trends over the same

periods of observation as shown in Figure 6.8. The Iroquois Point Inland site

experienced slightly higher chloride deposition rates than Wheeler AAF and the Iroquois

coastal site in all but one monitoring period. All three sites experience peak rates during

the same period from December 5-11, 2003. Similarly, all three sites experienced

relative low deposition rates in the preceding period from November 14 to December 5.

Page 35


0

500

1000

1500

2000

2500

30008/21

/2003

- 8/29/20

03

8/29/20

03 - 9/04

/2003

9/30/20

03 - 10/0

8/2003

10/8/20

03 - 10/1

7/2003

10/17/2003

- 10/31/2

003

10/31/2003

- 11/14/2

003

11/14/2003

- 12/05/2

003

12/5/20

03 - 12/1

1/2003

12/11/2003

- 1/05/2004

1/5/200

4 - 1/19

/2004

1/19/20

04 - 2/03

/2004

2/3/200

4 - 2/28/2

004

Chl

orid

e D

epos

ition

Rat

es (m

g/m

2/da

y) W heelerIroquois - CoastalIroquois - Inland

Figure 6.8: Comparison of Iroquois Coastal, Iroquois Inland and Wheeler Chloride Deposition Rates

A similar comparison for the Marine Corps Base sites is shown in Figure 6.9. Not

all monitoring periods correspond for the two sites, but the following observations can

still be made. The coastal site experienced much higher chloride deposition rates than

the inland site except for the period from December 18, 2003 to January 13, 2004.

During this period, the coastal site experienced its lowest deposition rate, while the

inland site saw its highest deposition rate. During the period from November 26 to

December 18, 2003 the coastal site reached its maximum recorded deposition rate while

the inland site experienced a relatively low deposition rate.

Page 36


0

500

1000

1500

2000

2500

30008/12

/2003

- 8/21/20

03

8/21/20

03 - 8/26

/2003

8/26/20

03 - 9/04

/2003

9/23/20

03 - 9/30

/2003

9/30/20

03 - 10/1

0/2003

10/31/2003

- 11/11/2

003

11/26/2003

-12/1

8/2003

12/18/2003

- 1/13/2004

1/13/20

04 - 2/03

/2004

2/3/200

4 - 3/11/2

004

Chl

orid

e D

epos

ition

Rat

es (m

g/m

2/da

y) MCBH - InlandMCBH - Coastal

Figure 6.9: Comparison of Marine Corps Base Coastal vs. Inland Chloride Deposition Rates

6.1.8 Wheeler AAF Low chloride deposition rates were experienced at Wheeler AAF site for most of

the monitoring period. This site is a considerable distance from the ocean in all

directions, with intervening mountain ranges to the NE and W. The slightly higher

chloride deposition rates during some of the monitoring periods are attributed to S and

SE winds that are less obstructed between the southern shoreline and the site. The

periods of high chloride deposition matched those at the Iroquois Point sites, situated on

the southern shoreline.

6.1.9 Iroquois Point Coastal and Inland Sites High and low chloride deposition rates occur during the same monitoring periods

for these two sites, though the rates at the inland site are slightly higher than the coastal

site. Low chloride deposition rates were experienced at Iroquois Point sites during

Page 37

predominantly N and NE winds. The periods with higher deposition rates generally

include a significant S or SE wind component, approaching the site as onshore winds.

For example, Figure 6.10 and Figure 6.11 show the wind direction rosette and wind

speed measured at the Iroquois Point inland site during a high chloride deposition

period. The slightly higher rates at the inland site are attributed to the proximity to Pearl

Harbor entrance and to the lack of vegetation around the inland site compared with the

coastal site.

12-5-03 to 12-11-03Frequency Rosette

0

0.1

0.2

0.3

0.4

0.50

10 2030

4050

607080

90

100110

120130

140150

160170180

190200210

220230

240250

260

270

280290

300310

320330

340350

W

S

E

N

Figure 6.10: Iroquois Point Inland Wind Direction During Period of High Chloride Deposition

Page 38

Wind Speed December 5 to 11, 2003

0

5

10

15

20

25

30

35

6-D

ec-0

3

7-D

ec-0

3

8-D

ec-0

3

9-D

ec-0

3

10-D

ec-0

3

11-D

ec-0

3

12-D

ec-0

3

Win

d Sp

eed

(mph

)

Figure 6.11: Iroquois Point Inland Wind Speed During Period of High Chloride Deposition

6.1.10 Marine Corps Base Coastal Site Low chloride deposition rates were experienced at Marine Corps Base coastal

site during the period from December 18, 2003 to January 13, 2004. The wind direction

frequency rosette for this period is shown in Figure 6.12. Wind direction varied from NE

to SW during this period. Figure 6.13 shows the wind speed in the 0 to 15 mph range

during this low chloride deposition period. The low chloride deposition rate is attributed

to the high frequency of SW winds during this monitoring period.

High chloride deposition rates were experienced at Marine Corps Base coastal

site during the period from November 26 to December 18, 2003. Figure 6.14 shows the

wind direction frequency rosette for this period, with ENE winds prevailing 81% of the

time. Figure 6.15 shows that the wind speeds during this high chloride deposition period

were significantly higher than the low deposition period. Chloride deposition rates

increase as the percentage of NE (onshore) winds increases, and as the wind speed

increases.

Page 39


0

0.1

0.2

0.3

0.4

0.50

10 2030

4050

6070

80

90

100

110120

130140

150160170

180190200

210220

230240

250

260

270

280

290300

310320

330340 350

W

S

E

N

Figure 6.12: Marine Corps Base Coastal Wind Direction During Period of Low Chloride Deposition

Windspeed December 18 to January 13, 2003

0

5

10

15

20

25

30

35

18-D

ec-0

319

-Dec

-03

20-D

ec-0

321

-Dec

-03

22-D

ec-0

323

-Dec

-03

24-D

ec-0

325

-Dec

-03

26-D

ec-0

327

-Dec

-03

28-D

ec-0

329

-Dec

-03

30-D

ec-0

331

-Dec

-03

1-Ja

n-04

2-Ja

n-04

3-Ja

n-04

4-Ja

n-04

5-Ja

n-04

6-Ja

n-04

7-Ja

n-04

8-Ja

n-04

9-Ja

n-04

10-J

an-0

411

-Jan

-04

12-J

an-0

413

-Jan

-04

14-J

an-0

4

Win

dspe

ed (m

ph)

Figure 6.13: Marine Corps Base Coastal Wind Speed During Period of Low Chloride Deposition

Page 40


0

0.1

0.2

0.3

0.4

0.50

10 2030

4050

6070

80

90

100

110120

130140

150160170

180190200

210220

230240

250

260

270

280

290300

310320

330340 350

W

S

E

N

Figure 6.14: Marine Corps Base Coastal Wind Direction During Period of High Chloride Deposition

Windspeed November 26 to December 18, 2003

0

5

10

15

20

25

30

35

26-N

ov-0

3

27-N

ov-0

3

28-N

ov-0

3

29-N

ov-0

3

30-N

ov-0

3

1-D

ec-0

3

2-D

ec-0

3

3-D

ec-0

3

4-D

ec-0

3

5-D

ec-0

3

6-D

ec-0

3

7-D

ec-0

3

8-D

ec-0

3

9-D

ec-0

3

10-D

ec-0

3

11-D

ec-0

3

12-D

ec-0

3

13-D

ec-0

3

14-D

ec-0

3

15-D

ec-0

3

16-D

ec-0

3

17-D

ec-0

3

18-D

ec-0

3

Win

dspe

ed (m

ph)

Figure 6.15: Marine Corps Base Coastal Wind Speed During Period of High Chloride Deposition

Page 41

6.1.11 Marine Corps Base Inland Site The chloride deposition rates measured at the MCBH inland site are significantly

lower than the coastal site, and compare more closely with the Iroquois Point and

Wheeler sites. This difference between the MCBH coastal and inland sites is attributed

to the presence of a small hill and dense vegetation between the two sites. The inland

site is therefore shielded from direct onshore winds, reflected by the lower wind speeds

measured at this site compared with the coastal site.

Low chloride deposition rates were experienced at Marine Corps Base inland site

during the period from November 26 to December 18, 2003. This is the same period

that the Marine Corps Base Coastal site experienced the highest chloride deposition

rate. Figure 6.16 shows the wind direction frequency rosette for this period. N winds

predominate during this period, however the wind speeds are low (Figure 6.17) and the

site is shielded by vegetation to the North.

High chloride deposition rates were experienced at Marine Corps Base inland

site during the period from December 18, 2003 to January 13, 2004, the same period the

coastal site experiences low chloride deposition rates. The wind direction frequency

rosette for this period of high chloride deposition is shown in Figure 6.18. A significant

portion of the wind is from the S. The wind speeds are also slightly higher than during

the low deposition period (Figure 6.19). The southerly exposure for this site is an open

airfield and the nearby Kaneohe Bay. The higher chloride deposition rate during this

period is attributed to southerly winds passing over the bay and airfield to the site.

Page 42


0

0.1

0.2

0.3

0.4

0.50

10 2030

4050

607080

90

100110

120130

140150

160170180

190200210

220230

240250

260

270

280290

300310

320330

340350

W

S

E

N

Figure 6.16: Marine Corps Base Inland Wind Direction During Period of Low Chloride Deposition

Windspeed November 26 to December 18, 2003

0

5

10

15

20

25

30

35

26-N

ov-0

3

27-N

ov-0

3

28-N

ov-0

3

29-N

ov-0

3

30-N

ov-0

3

1-D

ec-0

3

2-D

ec-0

3

3-D

ec-0

3

4-D

ec-0

3

5-D

ec-0

3

6-D

ec-0

3

7-D

ec-0

3

8-D

ec-0

3

9-D

ec-0

3

10-D

ec-0

3

11-D

ec-0

3

12-D

ec-0

3

13-D

ec-0

3

14-D

ec-0

3

15-D

ec-0

3

16-D

ec-0

3

17-D

ec-0

3

18-D

ec-0

3

Win

dspe

ed (m

ph)

Figure 6.17: Marine Corps Base Inland Wind Speed During Period of Low Chloride Deposition

Page 43


0

0.1

0.2

0.3

0.4

0.50

10 2030

4050

60

70

80

90

100

110

120130

140150

160170180

190200210

220230

240

250

260

270

280

290

300310

320330

340 350

W

S

E

N

Figure 6.18: Marine Corps Base Inland Wind Direction During Period of High Chloride Deposition

Windspeed December 18 to January 13, 2003

0

5

10

15

20

25

30

35

18-D

ec-0

319

-Dec

-03

20-D

ec-0

321

-Dec

-03

22-D

ec-0

323

-Dec

-03

24-D

ec-0

325

-Dec

-03

26-D

ec-0

327

-Dec

-03

28-D

ec-0

329

-Dec

-03

30-D

ec-0

331

-Dec

-03

1-Ja

n-04

2-Ja

n-04

3-Ja

n-04

4-Ja

n-04

5-Ja

n-04

6-Ja

n-04

7-Ja

n-04

8-Ja

n-04

9-Ja

n-04

10-J

an-0

411

-Jan

-04

12-J

an-0

413

-Jan

-04

14-J

an-0

4

Win

dspe

ed (m

ph)

Figure 6.19: Marine Corps Base Inland Wind Speed During Period of High Chloride Deposition

Page 44

6.2 PACIFIC RIM CORROSION RESEARCH PROGRAM For the past three years, L.H. Hihara and G.A. Hawthorn of the Pacific Rim

Corrosion Research Program have been monitoring chloride deposition rates at six

locations around the island of Oahu. Chloride deposition rates were monitored to

correlate between the corrosion rate of various materials and the amount of chlorides

entrained in the atmosphere at each of the six locations. Chloride deposition test

locations include Campbell Industrial Park, Coconut Island, Ewa Beach Inland, Kahuku,

Waipahu, and Manoa Valley. Figure 6.20 indicates the locations of each of the six test

sites.

Figure 6.20 Existing Site locations of the Pacific Rim Corrosion Research Program

Page 45

6.2.1 Manoa Valley Chloride deposition rates for the Manoa Valley site are shown in Figure 6.21.

Chloride deposition rates vary from 3.2 – 21.7 mg/m2/day. The highest rate was

recorded during July and August 2005 at 21.7 mg/m2/day. The lowest rate was 3.2

mg/m2/day, during October 2003. The average rate for the recorded duration was 9.2

mg/m2/day.

Figure 6.21 Manoa Valley Chloride Deposition Rates

Page 46

6.2.2 Waipahu Chloride deposition rates for the Waipahu site are shown in Figure 6.22.


recorded during November 2003 at 31.1 mg/m2/day. The lowest rate was 5.2 mg/m2/day,

during September 2003. The average rate for the recorded duration was 11.6

mg/m2/day.

Figure 6.22 Waipahu Chloride Deposition Rates

Page 47

6.2.3 Ewa Beach Inland Chloride deposition rates for the Ewa Beach Inland site are shown in Figure 6.23.


recorded during December 2005 at 21.1 mg/m2/day. The lowest rate was 4.9 mg/m2/day,

during September 2003. The average rate for the recorded duration was 10.7

mg/m2/day.

Figure 6.23 Ewa Beach Inland Chloride Deposition Rates

Page 48

6.2.4 Campbell Industrial Park Chloride deposition rates for the Campbell Industrial Park site are shown in

Figure 6.24. Chloride deposition rates vary from 11.6 – 79.8 mg/m2/day range. The

highest rate was recorded during January 2004 at 79.8 mg/m2/day. The lowest rate was

11.6 mg/m2/day, during September 2004. The average rate for the recorded duration

was 32.2 mg/m2/day.

Figure 6.24 Campbell Industrial Park Chloride Deposition Rates

Page 49

6.2.5 Kahuku Chloride deposition rates for the Kahuku site are shown in Figure 6.25. Chloride

deposition rates vary from 21.4 – 231.1 mg/m2/day. The highest rate was recorded

during November 2003 at 231.1 mg/m2/day. The lowest rate was 21.4 mg/m2/day, during

September 2003. The average rate for the recorded duration was 78.0 mg/m2/day.

Figure 6.25 Kahuku Chloride Deposition Rates

Page 50

6.2.6 Coconut Island Chloride deposition rates for the Coconut Island site are shown in Figure 6.26.


recorded during November 2003 at 285.2 mg/m2/day. The lowest rate was 23.2

mg/m2/day, during May 2005. The average rate for the recorded duration was 75.9

mg/m2/day.

Figure 6.26 Coconut Island Chloride Deposition Rates

6.3 CONCLUDING OBSERVATIONS 6.3.1 Corrosion of Galvanized Fasteners

Meteorological data for the five enclosure field sites show many similarities,

particularly relating to temperature and relative humidity, rainfall and solar radiation.

However, there are also significant differences, particularly in terms of wind speed and

Page 51

direction, and chloride deposition rates, even over short distances. The prevailing wind

direction, proximity to the coastline, condition of the shoreline and the resulting wave

action appear to have a major impact on chloride deposition rates. The presence of

vegetation and topographical features can significantly alter the exposure to onshore

winds carrying salt spray.

The significant difference between the chloride deposition rates at the Iroquois

Point coastal site compared with the Marine Corps Base coastal site is attributed to the

following influencing factors:

• Prevailing winds on the Island of Oahu are from the N and NE, with less

frequent winds from the S.

• Onshore wind speeds are generally much lower on southern shorelines than

at the MCBH coastal site.

• Because of offshore reefs on the south shore, there is only small shoreline

wave action at the Iroquois Point coastline, compared with significant open

ocean swells breaking on the MCBH coastline. In addition, the Iroquois

shoreline is a relatively flat sandy beach while the shoreline at the MCBH

coastal site is a combination of steep beach and rocky outcrops.

• There is vegetation between the shoreline and the Iroquois Point sites, while

the coastal site at MCBH is fully exposed to the onshore winds.

More conclusive results could be made if the chloride deposition rates were

monitored more frequently, over periods with predominantly the same wind speed and

direction. In addition, information on surf heights would confirm the relation of higher

chloride deposition rates to breaking wave size.

Page 52

6.3.2 Pacific Rim Corrosion Research Project Significant differences in chloride deposition rates are noticed between the

Manoa Valley, Waipahu, and Ewa Inland sites when compared to the Campbell, Kahuku,

and Coconut Island sites. This is due largely to the differences in location and proximity

of the ocean between all six sites. Similar chloride deposition results are found within

site locations of similar topographical regions and proximity to the ocean. This is evident

between the Kahuku and Coconut Island results located at the shorelines of the island.

Figure 6.27 indicates the average annual chloride deposition rates experienced for the

six site locations.

Finally, the yearly averaged chloride deposition rates are fairly similar. Although

chloride deposition rates are in constant fluctuation throughout the year, the yearly

averages are almost identical. Therefore, a one-year observation of the chloride

deposition rate is sufficient to create a yearly map for the island of Oahu.

Manoa CoconutIsland Campbell

Kahuku Waipahu

EwaBeach

2004 AVG

2005 AVG

12.0

66.1

32.6

70.3

13.510.96.8

74.5

35.0

74.3

8.9 10.20.0

10.0

20.0

30.0

40.0

50.0

60.0

70.0

80.0

Figure 6.27 Average Annual Chloride Deposition Rates

Pacific Rim Corrosion Research ProgramAverage Chloride Deposition Rate

2004 AVG

2005 AVG

Chl

orid

e D

epos

ition

Rat

e (m

g/m

2/da

y)

Page 53

REFERENCES [1] SLATER, JOHN E., “Corrosion of Metals in Association with Concrete,” American Society for Testing and Materials, 1983,

[2] KULICKI, J.M. AND MERTZ, D.R., “Guidelines for Evaluating Corrosion Effects in Existing Steel Bridges,” National Cooperative Highway Research Program Report, December 1990.

[3] CLEAR, KENNETH C. AND LEE, SEUNG KYOUNG., “Performance of Epoxy-Coated Reinforcing Steel in Highway Bridges,” National Cooperative Highway Research Program, 1995.

[4] HEIDERSBACH, R., “Corrosion Performance of Weathering Steel Structures,” Transportation Research Board, National Research Council, 1987.

[5] BERKE, NEAL S. AND WHITING, DAVID., “Corrosion Activity of Steel Reinforced Concrete Structures,” American Society for Testing and Materials, October 1996.

[6] CADY, P.D. AND WEYERS, R.E., Journal of Transportation Engineering, Vol.110, No. 1, January 1984, pp. 34-35.

[7] WEYERS, R.E., PROWELL, B.D., SPRINKEL, M.M., AND VORSTER, M.C., “Concrete Bridge Protection, Repair, and Rehabilitation Relative to Reinforcement Corrosion: A Methods Application Manual,” Strategic Highway Research Program, National Research Council, Washington, D.C., 193, pp. 268.

[8] GIBSON, FRANCIS W., “CORROSION, CONCRETE, AND CHLORIDES. Steel Corrosion in Concrete: Causes and Restraints.” American Concrete Institute, Detroit, 1987.

[9] PARENCHIO, W.F., “Corrosion of Reinforcing Steel,” ASTM STP169C, 1994

[10] ROBERTSON, I. N., AND WILLIAMS, L., “Corrosion of Galvanized Fasteners used in Cold-Formed Steel Framing” Research Report, Steel Framing Alliance and UHM/CEE 2005, University of Hawaii.

[11] Yunovich, M., and Lave, L., Cost of Corrosion, CC Technologies and Karen Jaske, US, viewed 16 February 2006, <http://www.corrosioncost.com/infrastructure/highway/>.

Page 54

Page 55

APPENDIX

ADDRESS POLE # ELEVATION (ft)

91-471 Fort Weaver Rd. 124 N150 21-18-45.2 158-00-15.7 37.1

CROSS-SECTION 1: EWA BEACH (Site 1)

GPS


Ewa By Gentry / 110 N400 II 21-20-10.7 158-01-10.1 72Iroquois Point Rd.


GPS


Fort Weaver Rd / 93 B 410783 BII 21-22-9.2 158-01-33.2 104.8Laulaunui St.

GPS



94-305 Kupuna Lp. 466 36-3866 A2 II 21-23-12.5 158-02-1.1 300


GPS


91-290 Kalaeloa Blvd. 2 M107 AS 21-18-48.3 158-05-59.0 22.6

CROSS-SECTION: 2 CAMPBELL INDUSTRIAL PARK (Site 1)

GPS


91-140 Kaomi Loop 20 848 21-28-5.6 158-06-36.6 36.4


GPS


2170 Lauwiliwili St. 22 M101 14 21-19-6.1 158-05-33.1 90.8


GPS


91-5020 Kapolei Parkway 18 M98 D2 21-19-48 158-04-3.5 110

GPS



599 Farrington Hwy 25 389735 S2 21-20-26.4 158-04-29.2 145.6

GPS



92-577 Makakilo Dr. 16X M09 21-20-51.4 158-04-52.6 400

GPS



92-6031 Nemo St. 20 3307 21-21-40.5 158-04-41.6 788

GPS



Kaukamana St. & 21-25-26.9 158-10-42.1 75Farington Hwy Intersection

GPS

CROSS-SECTION 3: WEST OAHU (Site 1)


87-226 Halemaluhia Pl. 29 29I 21-25-28 158-10-29.8 62

GPS



85-043 Waianae Valley Rd. 21-26-32 158-11-17.6 42

GPS



85-285 Waianae Valley Rd. 18 28 286 21-20-51.4 158-04-52.6 103

GPS


ADDRESS POLE # ELEVATION (ft)N W

Lehua Community Park 21-23-17.9 157-58-20.9 49

GPS

CROSS-SECTION 6: PEARL CITY (Site 1)


900 Kamehameha Hwy. 14 21-20-51.4 158-04-52.6 400

GPS



864 Hoomoana St. 21-24-21.8 157-57-47.7 247

GPS



2130 Ho'oki'eki'e St 21-24-54.1 157-57-21.9 423

GPS



5041 Kalanianaole Hwy N: 21° 16' 35" W: 157° 45' 36.5" 138

CROSS-SECTION 8: WAILUPE (Site 1)

GPS


800 West Hind Drive N: 21° 16' 45" W: 157° 45' 20" 65 Aina Haina Elementary


GPS


5006 Poola St. 74 66 N: 21° 16' 38" W: 157° 45' 44" 210


GPS


920 Hind Uka St. 52 439 N: 21° 17' 34" W: 157° 45' 17" 125 Wailupe Valley Elem. School


GPS


5311 Poola St. 74 20 N: 21° 16' 56" W: 157° 45' 33" 432


GPS


8270 Kalanianaole Hwy N: 21° 17' 0" W: 157° 43' 4" 47 Maunalua Bay

CROSS-SECTION 9: HAWAII KAI (Site 1)

GPS


7120 Wailua St. 42 305X N: 21° 17' 19" W: 157° 41' 58" 54 Over Bridge


GPS


1320 Kamehame St. 73 459 N: 21° 18' 22" W: 157° 40' 45" 722


GPS


1039 Hoa St. 73 479 N: 21° 18' 9" W: 157° 40' 43" 650


GPS


440 Kealahou St. N: 21° 17' 42" W: 157° 40' 24" 200 Koko Crater Botanical Garden


GPS


8988 Kalanianaole Hwy 90 I N: 21° 17' 27" W: 157° 39' 54" 69 Front of Beach


GPS


Makapuu Beach N: 21° 18' 49" W: 157° 39' 54" 80

MAKAPU'U BEACH PARK

GPS

KANEOHE - KAILUA


526 Kawailoa Road (?) 21-23-50 157-43-36.7 80

CROSS-SECTION 10: KAILUA (Site 1)

GPS

KANEOHE - KAILUA


Kuulei Rd. / Kailua Rd. Sign Damaged 21-23-41 157-44-35.6 90Intersection


GPS

KANEOHE - KAILUA


618 Hanalei Pl. 6 37 21-23-17.6 157-45-2.0 120


GPS

KANEOHE - KAILUA



GPS

KANEOHE - KAILUA


46-112 Nahiku St. (?) 21-25-23.7 157-48-08 57

CROSS-SECTION 11: KANEOHE (Site 1)

GPS

KANEOHE - KAILUA


46-170 Haiku Rd. 31 517 N150 II 21-25-11.2 157-48-28 175.5


GPS

KANEOHE - KAILUA


46-416 Kuneki St. 31 240 21-24-37 157-49-6.4 304.3


GPS

KANEOHE - KAILUA


46-484 Kuneki St. Sign Damaged 21-24-31.9 157-49-17.8 357.1


GPS

Documents

ISLAND MAPPING OF CHLORIDE DEPOSITION RATEFormed Steel, and 2) Pacific Rim Corrosion Research Project (PRCRP) on the Corrosion of Advanced Metallic Composites, have collected data