DEPARTMENT OF CIVIL AND ENVIRONMENTAL ENGINEERING ISLAND MAPPING OF CHLORIDE DEPOSITION RATE UNIVERSITY OF HAWAII COLLEGE OF ENGINEERING

Transcription

1 ISLAND MAPPING OF CHLORIDE DEPOSITION RATE Ronald R. Malalis and Ian N. Robertson Research Report UHM/CEE/06-05 May 2006 UNIVERSITY OF HAWAII COLLEGE OF ENGINEERING DEPARTMENT OF CIVIL AND ENVIRONMENTAL ENGINEERING

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3 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. iii

4 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. iv

5 TABLE OF CONTENTS CHAPTER 1 INTRODUCTION PROJECT OUTLINE RESEARCH OBJECTIVES PROJECT SCOPE Significant factors affecting the chloride deposition rate...3 CHAPTER 2 LITERATURE REVIEW IMPACT OF CORROSION ON INFRASTRUCTURE COST OF CORROSION CORROSION PROCESS ENVIRONMENTAL EFFECTS SOURCES OF CHLORIDES Sources of Chloride can include but are not limited to:...9 CHAPTER 3 REMEDIAL MEASURES IMPLEMENTING PONTIS CORROSION PREDICTION MODEL, LIFE IMPLEMENTATION AND BENEFITS...13 CHAPTER 4 SITE SELECTION SITE SELECTION RATIONALE CHLORIDE DEPOSITION CROSS-SECTIONS Preliminary Site Selection...18 CHAPTER 5 CHLORIDE MONITORING WET CANDLE METHOD, ISO 9225:1993(E) Sampling Apparatus, Wet Candle Exposure Rack EQUIPMENT Chloride Test System Fastening System Weather Monitoring Station SAMPLING...26 CHAPTER 6 PRELIMINARY RESULTS CORROSION OF GALVANIZED FASTENERS USED IN COLD-FORMED STEEL FRAMING...27 v

6 6.1.1 Chloride Deposition Rate Wheeler AAF Site Iroquois Point Coastal Site Iroquois Point Inland Site Marine Corps Base Coastal Site Marine Corps Base Inland Site Analysis of Chloride Data Wheeler AAF Iroquois Point Coastal and Inland Sites Marine Corps Base Coastal Site Marine Corps Base Inland Site PACIFIC RIM CORROSION RESEARCH PROGRAM Manoa Valley Waipahu Ewa Beach Inland Campbell Industrial Park Kahuku Coconut Island CONCLUDING OBSERVATIONS Corrosion of Galvanized Fasteners Pacific Rim Corrosion Research Project...52 vi

7 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 vii

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9 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 Pontis 1, 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, Page 1

10 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-depositionrate 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. Page 2

11 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 3

12 Figure 1.1 Existing and Proposed Chloride Sites from CEE and ME Departments Page 4

13 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 5

14 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 wellknown 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 6

15 technology and research capabilities has been made, the basic principles of chlorideinduced 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 7

16 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. Page 8

17 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 9

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19 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 highways 2. 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, Page 11

20 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 percent 3. 3 AASHTO Innovative Highway Technologies, Page 12

21 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 13

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23 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 15

24 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 16

25 Flat Terrain Mountainous Open Terrain Obstructions Sandy Shore Rocky Shore With Reef Without Reef Low Roadway High Roadway 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. Page 17

26 Figure 4.3 Proposed Chloride Cross Sections 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. Page 18

27 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 Fort Weaver Rd. 124 N Ewa By Gentry / Iroquois Point Rd. 110 N400 II Fort Weaver Rd / Laulaunui St. 93 B BII Kupuna Lp A2 II CROSS-SECTION 2: KAPOLEI Kalaeloa Blvd. 2 M107 AS Kaomi Loop Lauwiliwili St. 22 M Kapolei Parkway 18 M98 D Farington Hwy S Makakilo Dr. 16X M Nemo St CROSS-SECTION 3: WEST OAHU 1 Kaukamana St. & Farrington Hwy Halemaluhia Pl I Waianae Valley Rd Waianae Valley Rd CROSS-SECTION 4: NORTH SHORE To Be Determined CROSS-SECTION 5: AIEA To Be Determined Page 19

28 SITE ADDRESS POLE # GPS ELEV. (ft) N W CROSS-SECTION 6: PEARL CITY 1 Lehua Community Park Kamehameha Hwy Hoomoana St Ho'oki'eki'e St CROSS-SECTION 7: HONOLULU To Be Determined CROSS-SECTION 8: WAILUPE Kalanianaole Hwy N: 21 16' 35" W: ' 36.5" West Hind Drive N: 21 16' 45" W: ' 20" Poola St N: 21 16' 38" W: ' 44" Hind Uka St N: 21 17' 34" W: ' 17" Poola St N: 21 16' 56" W: ' 33" 432 CROSS-SECTION 9: HAWAII KAI Kalanianaole Hwy N: 21 17' 0" W: ' 4" 47 Maunalua Bay Wailua St X N: 21 17' 19" W: ' 58" 54 Over Bridge Kamehame St N: 21 18' 22" W: ' 45" Hoa St N: 21 18' 9" W: ' 43" Kealahou St. N: 21 17' 42" W: ' 24" 157 Koko Crater Botanical Garden Page 20

29 SITE ADDRESS POLE # GPS ELEV. (ft) N W Kalanianaole Hwy 90 I N: 21 17' 27" W: ' 54" 59 Front of Beach 7 Makapu'u Beach N: 21 18' 49" W: ' 54" 86 CROSS-SECTION 10: KAILUA Kawailoa Rd. (Kailua Beach Park) No Number Intersection of Ku'ulei & Kailua Rd. Sign Damaged Hanalei Pl Kailua Rd. & Castle Hospital L II CROSS-SECTION 11: KANEOHE Nahiku St. Sign Damaged Haiku Rd N150 II Kuneki St Kuneki St. Sign Damaged CROSS-SECTION 12: LAI'E / KAHUKU To Be Determined Page 21

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31 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/(m 2 d)] 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 cm 2, 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 23

32 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 24

33 5.2 EQUIPMENT 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 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 Weather Monitoring Station A weather monitoring system will be installed at each of the twelve crosssections 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 25

34 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 26

35 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 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 27

36 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/m 2 /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 Wheeler AAF Site Chloride deposition rates for the Wheeler AAF site are shown in Figure 6.1:. Chloride deposition rates vary from mg/m 2 /day range. The highest rate was recorded during the December 5-11, 2003 period at 581 mg/m 2 /day. The lowest rate was 80 mg/m 2 /day, during the January 5 to February 3, 2004 period. Page 28

37 Chloride Deposition Rate 3000 Chloride Deposition (mg/m2/day) /18/2003-8/26/2003 9/4/2003-9/23/2003 9/23/2003-9/30/ /8/ /17/ /17/ /31/ /31/ /14/ /14/ /05/ /5/ /11/ /11/2003-1/05/2004 1/5/2004-2/03/2004 2/28/2004-3/22/2004 Figure 6.1: Wheeler AAF Chloride Deposition Rates 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/m 2 /day. Wheeler AAF experienced the same peak period as the Iroquois Point coastal site. The lowest rate was 167 mg/m 2 /day during the February 3-28, 2004 period. Page 29

38 Chloride Deposition Rate 3000 Chloride Deposition (mg/m2/day) /13/2003-8/21/2003 8/21/2003-8/29/2003 8/29/2003-9/04/2003 9/30/ /08/ /8/ /17/ /17/ /31/ /31/ /14/ /14/ /05/ /5/ /11/ /11/2003-1/05/2004 1/5/2004-1/19/2004 1/19/2004-2/03/2004 2/3/2004-2/28/2004 Figure 6.2: Iroquois Point Coastal Chloride Deposition Rates 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/m 2 /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/m 2 /day, during the November 14 to December 5, 2004 period. Page 30

39 Chloride Deposition Rate 3000 Chloride Deposition (mg/m2/day) /21/2003-8/29/2003 8/29/2003-9/04/2003 9/30/ /08/ /8/ /17/ /17/ /31/ /31/ /14/ /14/ /05/ /5/ /11/ /11/2003-1/05/2004 1/5/2004-1/19/2004 1/19/2004-2/03/2004 2/3/2004-2/28/2004 2/28/2004-3/18/2004 Figure 6.3: Iroquois Point Inland Chloride Deposition Rates Chloride Deposition Rate 3000 Chloride Deposition (mg/m2/day) /12/2003-8/21/2003 8/21/2003-8/26/2003 8/26/2003-9/04/2003 9/23/2003-9/30/2003 9/30/ /10/ /11/ /26/ /26/ /18/ /18/2003-1/13/2004 2/3/2004-3/11/2004 Figure 6.4: Marine Corps Base Coastal Chloride Deposition Rates Page 31

40 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 mg/m 2 /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/m 2 /day. The lowest rate was 216 mg/m 2 /day, during the December 18, 2003 to January 13, 2004 period 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 mg/m 2 /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/m 2 /day, less than one third the rate seen at the coastal site for the same period. Chloride Deposition Rate 3000 Chloride Deposition (mg/m2/day) /12/2003-8/21/2003 8/21/2003-8/26/2003 8/26/2003-9/04/2003 9/23/2003-9/30/2003 9/30/ /10/ /31/ /11/ /26/ /18/ /18/2003-1/13/2004 1/13/2004-2/03/2004 2/3/2004-3/11/2004 Figure 6.5: Marine Corps Base Inland Chloride Deposition Rates Page 32

41 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. Chloride Deposition Rates 3000 Chloride Deposition Rate (mg/m 2 /day) MCBH Coastal MCBH Inland Iriquois Coastal Iriquois Inland Wheeler AAF Figure 6.6: Chloride Deposition Rates Page 33

42 Average Chloride Deposition Rates Chloride Deposition Rate (mg/m 2 /day) MCBH Coastal MCBH Inland Iroquois Coastal Iroquois Inland Wheeler Location 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, Similarly, all three sites experienced relative low deposition rates in the preceding period from November 14 to December 5. Page 34

43 Chloride Deposition Rates Chloride Deposition Rates (mg/m2/day) W heeler Iroquois - Coastal Iroquois - Inland 8/21/2003-8/29/2003 8/29/2003-9/04/2003 9/30/ /08/ /8/ /17/ /17/ /31/ /31/ /14/ /14/ /05/ /5/ /11/ /11/2003-1/05/2004 1/5/2004-1/19/2004 1/19/2004-2/03/2004 2/3/2004-2/28/2004 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, 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 35

44 Chloride Deposition Rates Chloride Deposition Rates (mg/m2/day) MCBH - Inland MCBH - Coastal 8/12/2003-8/21/2003 8/21/2003-8/26/2003 8/26/2003-9/04/2003 9/23/2003-9/30/2003 9/30/ /10/ /31/ /11/ /26/ /18/ /18/2003-1/13/2004 1/13/2004-2/03/2004 2/3/2004-3/11/2004 Figure 6.9: Comparison of Marine Corps Base Coastal vs. Inland Chloride Deposition Rates 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 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 36

45 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 to Frequency Rosette N W E S Figure 6.10: Iroquois Point Inland Wind Direction During Period of High Chloride Deposition Page 37

46 Wind Speed December 5 to 11, Dec-03 7-Dec-03 8-Dec-03 9-Dec Dec Dec Dec-03 Wind Speed (mph) Figure 6.11: Iroquois Point Inland Wind Speed During Period of High Chloride Deposition 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, The wind direction frequency rosette for this period is shown in Figure 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, 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 38

47 W to Frequency Rosette N 180 S E Figure 6.12: Marine Corps Base Coastal Wind Direction During Period of Low Chloride Deposition Windspeed (mph) Windspeed December 18 to January 13, Dec Dec Dec Dec Dec Dec Dec Dec Dec Dec Dec Dec Dec Dec-03 1-Jan-04 2-Jan-04 3-Jan-04 4-Jan-04 5-Jan-04 6-Jan-04 7-Jan-04 8-Jan-04 9-Jan Jan Jan Jan Jan Jan-04 Figure 6.13: Marine Corps Base Coastal Wind Speed During Period of Low Chloride Deposition Page 39

48 W to Frequency Rosette N 180 S E Figure 6.14: Marine Corps Base Coastal Wind Direction During Period of High Chloride Deposition Windspeed (mph) Windspeed November 26 to December 18, Nov Nov Nov Nov Nov-03 1-Dec-03 2-Dec-03 3-Dec-03 4-Dec-03 5-Dec-03 6-Dec-03 7-Dec-03 8-Dec-03 9-Dec Dec Dec Dec Dec Dec Dec Dec Dec Dec-03 Figure 6.15: Marine Corps Base Coastal Wind Speed During Period of High Chloride Deposition Page 40

49 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, 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 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 41

50 to Frequency Rosette N W E S Figure 6.16: Marine Corps Base Inland Wind Direction During Period of Low Chloride Deposition Windspeed (mph) Windspeed November 26 to December 18, Nov Nov Nov Nov Nov-03 1-Dec-03 2-Dec-03 3-Dec-03 4-Dec-03 5-Dec-03 6-Dec-03 7-Dec-03 8-Dec-03 9-Dec Dec Dec Dec Dec Dec Dec Dec Dec Dec-03 Figure 6.17: Marine Corps Base Inland Wind Speed During Period of Low Chloride Deposition Page 42

51 W to Frequency Rosette N 180 S E Figure 6.18: Marine Corps Base Inland Wind Direction During Period of High Chloride Deposition Windspeed (mph) Windspeed December 18 to January 13, Dec Dec Dec Dec Dec Dec Dec Dec Dec Dec Dec Dec Dec Dec-03 1-Jan-04 2-Jan-04 3-Jan-04 4-Jan-04 5-Jan-04 6-Jan-04 7-Jan-04 8-Jan-04 9-Jan Jan Jan Jan Jan Jan-04 Figure 6.19: Marine Corps Base Inland Wind Speed During Period of High Chloride Deposition Page 43

52 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 44

53 6.2.1 Manoa Valley Chloride deposition rates for the Manoa Valley site are shown in Figure Chloride deposition rates vary from mg/m 2 /day. The highest rate was recorded during July and August 2005 at 21.7 mg/m 2 /day. The lowest rate was 3.2 mg/m 2 /day, during October The average rate for the recorded duration was 9.2 mg/m 2 /day. Figure 6.21 Manoa Valley Chloride Deposition Rates Page 45

54 6.2.2 Waipahu Chloride deposition rates for the Waipahu site are shown in Figure Chloride deposition rates vary from mg/m 2 /day. The highest rate was recorded during November 2003 at 31.1 mg/m 2 /day. The lowest rate was 5.2 mg/m 2 /day, during September The average rate for the recorded duration was 11.6 mg/m 2 /day. Figure 6.22 Waipahu Chloride Deposition Rates Page 46

55 6.2.3 Ewa Beach Inland Chloride deposition rates for the Ewa Beach Inland site are shown in Figure Chloride deposition rates vary from mg/m 2 /day. The highest rate was recorded during December 2005 at 21.1 mg/m 2 /day. The lowest rate was 4.9 mg/m 2 /day, during September The average rate for the recorded duration was 10.7 mg/m 2 /day. Figure 6.23 Ewa Beach Inland Chloride Deposition Rates Page 47

56 6.2.4 Campbell Industrial Park Chloride deposition rates for the Campbell Industrial Park site are shown in Figure Chloride deposition rates vary from mg/m 2 /day range. The highest rate was recorded during January 2004 at 79.8 mg/m 2 /day. The lowest rate was 11.6 mg/m 2 /day, during September The average rate for the recorded duration was 32.2 mg/m 2 /day. Figure 6.24 Campbell Industrial Park Chloride Deposition Rates Page 48

57 6.2.5 Kahuku Chloride deposition rates for the Kahuku site are shown in Figure Chloride deposition rates vary from mg/m 2 /day. The highest rate was recorded during November 2003 at mg/m 2 /day. The lowest rate was 21.4 mg/m 2 /day, during September The average rate for the recorded duration was 78.0 mg/m 2 /day. Figure 6.25 Kahuku Chloride Deposition Rates Page 49

58 6.2.6 Coconut Island Chloride deposition rates for the Coconut Island site are shown in Figure Chloride deposition rates vary from mg/m 2 /day. The highest rate was recorded during November 2003 at mg/m 2 /day. The lowest rate was 23.2 mg/m 2 /day, during May The average rate for the recorded duration was 75.9 mg/m 2 /day. Figure 6.26 Coconut Island Chloride Deposition Rates 6.3 CONCLUDING OBSERVATIONS 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 50

59 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 51

60 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. Pacific Rim Corrosion Research Program Average Chloride Deposition Rate Chloride Deposition Rate (mg/m2/day) Manoa 12.0 Coconut Island Campbell Kahuku Waipahu 2004 AVG 2005 AVG Ew a Beach AVG 2004 AVG Figure 6.27 Average Annual Chloride Deposition Rates Page 52

61 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 [3] CLEAR, KENNETH C. AND LEE, SEUNG KYOUNG., Performance of Epoxy-Coated Reinforcing Steel in Highway Bridges, National Cooperative Highway Research Program, [4] HEIDERSBACH, R., Corrosion Performance of Weathering Steel Structures, Transportation Research Board, National Research Council, [5] BERKE, NEAL S. AND WHITING, DAVID., Corrosion Activity of Steel Reinforced Concrete Structures, American Society for Testing and Materials, October [6] CADY, P.D. AND WEYERS, R.E., Journal of Transportation Engineering, Vol.110, No. 1, January 1984, pp [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 [8] GIBSON, FRANCIS W., CORROSION, CONCRETE, AND CHLORIDES. Steel Corrosion in Concrete: Causes and Restraints. American Concrete Institute, Detroit, [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, < Page 53

62 Page 54

63 APPENDIX Page 55

64 CROSS-SECTION 1: EWA BEACH (Site 1) ADDRESS POLE # GPS ELEVATION (ft) Fort Weaver Rd. 124 N

65 CROSS-SECTION 1: EWA BEACH (Site 2) ADDRESS POLE # GPS ELEVATION (ft) Ewa By Gentry / 110 N400 II Iroquois Point Rd.

66 CROSS-SECTION 1: EWA BEACH (Site 3) ADDRESS POLE # GPS ELEVATION (ft) Fort Weaver Rd / 93 B BII Laulaunui St.

67 CROSS-SECTION 1: EWA BEACH (Site 4) ADDRESS POLE # GPS ELEVATION (ft) Kupuna Lp A2 II

68 CROSS-SECTION: 2 CAMPBELL INDUSTRIAL PARK (Site 1) ADDRESS POLE # GPS ELEVATION (ft) Kalaeloa Blvd. 2 M107 AS

69 CROSS-SECTION: 2 CAMPBELL INDUSTRIAL PARK (Site 2) ADDRESS POLE # GPS ELEVATION (ft) Kaomi Loop

70 CROSS-SECTION: 2 CAMPBELL INDUSTRIAL PARK (Site 3) ADDRESS POLE # GPS ELEVATION (ft) 2170 Lauwiliwili St. 22 M

71 CROSS-SECTION: 2 CAMPBELL INDUSTRIAL PARK (Site 4) ADDRESS POLE # GPS ELEVATION (ft) Kapolei Parkway 18 M98 D

72 CROSS-SECTION: 2 CAMPBELL INDUSTRIAL PARK (Site 5) ADDRESS POLE # GPS ELEVATION (ft) 599 Farrington Hwy S

73 CROSS-SECTION: 2 CAMPBELL INDUSTRIAL PARK (Site 6) ADDRESS POLE # GPS ELEVATION (ft) Makakilo Dr. 16X M

74 CROSS-SECTION: 2 CAMPBELL INDUSTRIAL PARK (Site 7) ADDRESS POLE # GPS ELEVATION (ft) Nemo St

75 CROSS-SECTION 3: WEST OAHU (Site 1) ADDRESS POLE # GPS ELEVATION (ft) Kaukamana St. & Farington Hwy Intersection

76 CROSS-SECTION 3: WEST OAHU (Site 2) ADDRESS POLE # GPS ELEVATION (ft) Halemaluhia Pl I

77 CROSS-SECTION 3: WEST OAHU (Site 3) ADDRESS POLE # GPS ELEVATION (ft) Waianae Valley Rd

78 CROSS-SECTION 3: WEST OAHU (Site 4) ADDRESS POLE # GPS ELEVATION (ft) Waianae Valley Rd

79 CROSS-SECTION 6: PEARL CITY (Site 1) ADDRESS POLE # GPS ELEVATION (ft) N W Lehua Community Park

80 CROSS-SECTION 6: PEARL CITY (Site 2) ADDRESS POLE # GPS ELEVATION (ft) N W 900 Kamehameha Hwy

81 CROSS-SECTION 6: PEARL CITY (Site 3) ADDRESS POLE # GPS ELEVATION (ft) N W 864 Hoomoana St

82 CROSS-SECTION 6: PEARL CITY (Site 4) ADDRESS POLE # GPS ELEVATION (ft) N W 2130 Ho'oki'eki'e St

83 CROSS-SECTION 8: WAILUPE (Site 1) ADDRESS POLE # GPS ELEVATION (ft) 5041 Kalanianaole Hwy N: 21 16' 35" W: ' 36.5" 138

84 CROSS-SECTION 8: WAILUPE (Site 2) ADDRESS POLE # GPS ELEVATION (ft) 800 West Hind Drive N: 21 16' 45" W: ' 20" 65 Aina Haina Elementary

85 CROSS-SECTION 8: WAILUPE (Site 3) ADDRESS POLE # GPS ELEVATION (ft) 5006 Poola St N: 21 16' 38" W: ' 44" 210

86 CROSS-SECTION 8: WAILUPE (Site 4) ADDRESS POLE # GPS ELEVATION (ft) 920 Hind Uka St N: 21 17' 34" W: ' 17" 125 Wailupe Valley Elem. School

87 CROSS-SECTION 8: WAILUPE (Site 5) ADDRESS POLE # GPS ELEVATION (ft) 5311 Poola St N: 21 16' 56" W: ' 33" 432

88 CROSS-SECTION 9: HAWAII KAI (Site 1) ADDRESS POLE # GPS ELEVATION (ft) 8270 Kalanianaole Hwy N: 21 17' 0" W: ' 4" 47 Maunalua Bay

89 CROSS-SECTION 9: HAWAII KAI (Site 2) ADDRESS POLE # GPS ELEVATION (ft) 7120 Wailua St X N: 21 17' 19" W: ' 58" 54 Over Bridge

90 CROSS-SECTION 9: HAWAII KAI (Site 3) ADDRESS POLE # GPS ELEVATION (ft) 1320 Kamehame St N: 21 18' 22" W: ' 45" 722

91 CROSS-SECTION 9: HAWAII KAI (Site 4) ADDRESS POLE # GPS ELEVATION (ft) 1039 Hoa St N: 21 18' 9" W: ' 43" 650

92 CROSS-SECTION 9: HAWAII KAI (Site 5) ADDRESS POLE # GPS ELEVATION (ft) 440 Kealahou St. N: 21 17' 42" W: ' 24" 200 Koko Crater Botanical Garden

93 CROSS-SECTION 9: HAWAII KAI (Site 6) ADDRESS POLE # GPS ELEVATION (ft) 8988 Kalanianaole Hwy 90 I N: 21 17' 27" W: ' 54" 69 Front of Beach

94 MAKAPU'U BEACH PARK ADDRESS POLE # GPS ELEVATION (ft) Makapuu Beach N: 21 18' 49" W: ' 54" 80

95 KANEOHE - KAILUA CROSS-SECTION 10: KAILUA (Site 1) ADDRESS POLE # GPS ELEVATION (ft) 526 Kawailoa Road (?)

96 KANEOHE - KAILUA CROSS-SECTION 10: KAILUA (Site 2) ADDRESS POLE # GPS ELEVATION (ft) Kuulei Rd. / Kailua Rd. Sign Damaged Intersection

97 KANEOHE - KAILUA CROSS-SECTION 10: KAILUA (Site 3) ADDRESS POLE # GPS ELEVATION (ft) 618 Hanalei Pl

98 KANEOHE - KAILUA CROSS-SECTION 10: KAILUA (Site 4) ADDRESS POLE # GPS ELEVATION (ft)

99 KANEOHE - KAILUA CROSS-SECTION 11: KANEOHE (Site 1) ADDRESS POLE # GPS ELEVATION (ft) Nahiku St. (?)

100 KANEOHE - KAILUA CROSS-SECTION 11: KANEOHE (Site 2) ADDRESS POLE # GPS ELEVATION (ft) Haiku Rd N150 II

101 KANEOHE - KAILUA CROSS-SECTION 11: KANEOHE (Site 3) ADDRESS POLE # GPS ELEVATION (ft) Kuneki St

102 KANEOHE - KAILUA CROSS-SECTION 11: KANEOHE (Site 4) ADDRESS POLE # GPS ELEVATION (ft) Kuneki St. Sign Damaged