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31 tions have also been developed. The condition of the concrete research installation, and monitoring and maintenance of superstructure, availability of power, chloride ion content, and cathodic protection systems or other corrosion mitigation half-cell potential survey results are used for ascertaining the technologies. need for a cathodic protection system on a bridge deck. A Spe- cial Provision is added to every contract that requires installa- FDOT has a very robust research and development pro- tion of a cathodic protection system. Construction inspectors gram in the area of corrosion mitigation. It has developed trained by personnel from Research perform inspections during many of the technologies currently in use on substructure ele- installations and Traffic Signal Electricians conduct acceptance ments. The corrosion group has been involved in the devel- testing on rectifiers. All maintenance work on the cathodic pro- opment of various cathodic protection systems since the early tection systems is done in-house. 1970s. Initially, all research was performed by the corrosion group. Later, the program was expanded, and several Florida Almost all of the cathodic protection systems, 161 of 167, universities were contracted to perform both theoretical and are installed on bridge decks, with the remaining systems field research. Consultants are also used in some of the research installed on substructure elements. A majority of the deck efforts. The use of zinc penny sheets, conductive rubber, zinc systems are slotted and use the platinumniobium anode mesh in jackets, arc sprayed zinc above the tidal zones, and wire. The oldest titanium-mixed metal oxide anode-based bulk anodes on marine pilings have all been outcomes of system in the state is 19 years old. In the last 8 years, all deck these research efforts. systems installed have been mixed metal oxide anode sys- tems. The current Contract Specifications provide a choice As would be expected in any such undertaking, the Cor- between slotted and mixed metal oxide; however, the mixed rosion Laboratory initially experienced failures in some of metal oxides have been preferred. the earlier systems. Owing to a lack of confidence, many of the districts were initially reluctant to implement the tech- With more than three decades of use, the state has experi- nology developed or adopted by the Corrosion Laboratory. enced much success, but some failures as well. The ferex As they started to experience success and bridge inspection anode-based systems installed on two dozen bridges failed in teams recognized the reduction in inspection and maintenance fewer than 5 years and had to be replaced. MDOT believes needs, districts adopted the technologies and procedures that the choices available in the marketplace are limited developed and started to implement cathodic protection tech- and that monopoly is stifling innovation. There are only two nology on all of its structures. experienced contractors in the state. They would prefer to see more cathodic protection systems on substructure elements; The Corrosion Laboratory provides a complete corrosion however, they believe innovation is necessary for large-scale package. It can evaluate the structure and ascertain the need adoption. for corrosion mitigation, provide options for corrosion con- trol, provide quality control and quality assurance services Florida and assistance during construction, and monitor and maintain the cathodic protection systems. The Corrosion Laboratory Florida has 6,000 bridges located in the marine environment does not limit itself to cathodic protection technology; it uses and corrosion of the substructures is observable within 12 years all corrosion mitigation technologies depending on their of construction. The collapse of the Anclote River Bridge applicability and the need for extension in service life. Con- in Pinellas County on December 17, 1968, and the accom- sidering the number of structures in need of maintenance and panying loss of life led to an investigation that concluded that the size of the staff, the Corrosion Laboratory uses consul- the failure had resulted from corrosion of the reinforced con- tants as and when needed, and districts also have begun to crete bridge components. To ensure that the corrosion prob- use local consultants for the same purpose. lem was properly managed, the state hired a corrosion expert who started the FDOT corrosion program. Now the state FDOT has a formal policy for the use and application of has a Corrosion Laboratory housed in the Central Office of cathodic protection system technology. Standards have been FDOT, which is a part of the Materials Office. The Corrosion developed for several different types of cathodic protection Laboratory has nine full-time personnel, various contract systems that are a part of the Bridge Repair Manual. The workers, and two consultants to assist it in carrying out its bridge owners hire local consultants for the repair and rehabi- mission. Initially, the corrosion program trained personnel litation programs, who use FDOT standards to design cathodic in-house. Later, they hired people with formal training protection systems for the project. The Corrosion Laboratory in corrosion. Its personnel receive training from NACE reviews all cathodic protection systems designed for imple- programs and keep current with the corrosion technology mentation on state-owned structures. Many of the local through attendance at various conferences. The Corrosion bridge consultants in the state have acquired sufficient exper- Laboratory, funded by the State Material Office Budget, tise to design cathodic protection systems and there are sev- is fully equipped to perform much of the material testing and eral Corrosion Consultants who either provide services to the conduct research efforts in corrosion-related areas. The labo- bridge consultants, the districts, or to the Corrosion Labora- ratory is also capable of executing condition evaluation, tory. This policy of allowing consultants to design cathodic

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32 protection systems has created a significant pool of skilled under cathodic protection. They pioneered the practical appli- manpower that the state can access for the implementation of cation of cathodic protection for preservation of existing major this technology. The installation of the cathodic protection historic coastal bridges. systems can be done by any qualified contractor. However, each project is required to have the services of an independent The historic Alsea Bay Bridge suffered significant NACE-certified Cathodic Protection Specialist to provide corrosion-induced damage and had to be replaced. The pub- quality control and quality assurance services. The indepen- lic process for the replacement was difficult and it cost the dent specialist not only provides inspection services, but also Oregon DOT (ODOT) $24 million more than the simpler trains and provides guidance to the contractors with the bridge it had planned to use for replacement. This prompted installation of the cathodic protection system. Because many it to search for technologies to preserve its other historic contractors in the state have acquired experience in the instal- bridges and avoid replacement for as long as possible. One of lation of the cathodic protection systems, competition in the the crews in the DOT had electrical and mechanical engi- marketplace has been maintained. neers who were familiar with cathodic protection technology used on pipelines, marine vessels, and offshore oil platforms, Monitoring and routine maintenance of all cathodic pro- and they proposed its use on reinforced concrete structures. tection systems is performed by the Corrosion Laboratory. If At that time, Caltrans had just completed a research project a major repair is required, then either the bridge crew or a con- to test thermal-sprayed zinc as an anode on the surface of the tractor is used. As the inventory of cathodic protection sys- reinforced concrete components. Oregon selected the arc tems in the state grows, FDOT is finding it difficult to manage sprayed zinc anode for application on historic structures and all the systems in-house and is starting to use consultants for completed its first application on the Cape Creek Bridge in this purpose. The galvanic cathodic protection systems are 1990. Including the ongoing project on Coos Bay South monitored once a year. When the work load cannot be han- Approaches, there are a total of 11 bridges with cathodic pro- dled by the manpower available, the best performing systems tection systems in the state. Although the number of bridges are temporarily dropped from the monitoring program. The is not large, the surface area protected is. impressed current systems are monitored using remote moni- toring technology. There is only one impressed current sys- ODOT has a Bridge Preservation Group that includes struc- tem in the inventory that does not have a remote monitoring tural, electrical, geotechnical, hydraulics, and corrosion posi- unit and the Corrosion Laboratory staff visit the system once tions and is charged with the preservation of all bridge struc- each month. Data from the remote monitoring systems are tures in the state. There are two corrosion positions: Corrosion reviewed weekly. To ensure that it is able to properly monitor Protection Engineer and Corrosion Design in the group. This the impressed current cathodic protection systems, a remote group has developed specifications for design and application monitoring unit was specifically designed for their needs. of the arc sprayed cathodic protection systems, and has also experimented with various other surface-applied anodes. Cor- The Corrosion Laboratory, in an interview, indicated that rosion consultants are used in conjunction with their in-house because of its experience and expertise in the area of corro- staff for design and to provide quality control during installa- sion, it is not subject to extensive sales and marketing efforts. tion. Monitoring and maintenance is done in-house. Many of the products used in the state are first evaluated by the Corrosion Laboratory. The anode materials available in the marketplace do address their present needs; however, California innovation and more competition in the anode marketplace would be welcome. Caltrans was the pioneer in the application of cathodic pro- tection to reinforced concrete structures. It was the first to With the use of cathodic protection technology, FDOT install cathodic protection systems on bridge decks. Cathodic has experienced a reduction in maintenance costs. Its inven- protection is best suited for its marine structures. Deicing salt tory includes impressed current systems that have been in exposure is limited to the mountainous regions of the state, operation for 20 years and galvanic systems that have been where the overlay systems on bridge decks are often dam- operational for 10 to 15 years. aged by the chains on heavy trucks during the winter and are not preferred in those applications. Cathodic protection is considered to be last option and is used only when the expo- Oregon sure environment is such that no other corrosion control sys- tem will provide the desired service-life extension. Caltrans Oregon has many historic structures and much of their cor- developed the coke breeze cathodic protection system and rosion problem stems from exposure to the marine environ- experimented with several coating systems including arc ment. Its need to protect superstructure elements on many of sprayed zinc. It has also experimented with a conductive its marine structures has resulted in the state being the largest polyester concrete bridge deck cathodic protection system. users of surface-applied cathodic protection systems such as arc sprayed zinc. With the completion of ongoing construc- The Caltrans Corrosion Technology Branch (CTB) is cur- tion, Oregon will have 1.17 million square feet of concrete rently staffed by four engineers and two technicians. The exis-

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33 tence of the CTB can be traced back to the time of Richard tection systems in controlling corrosion of its reinforced con- Stratfull who pioneered cathodic protection application on crete bridge elements. The study was lead by a ConnDOT reinforced concrete structures. Stratfull was instrumental in Principal Investigator and the cathodic protection systems developing the awareness of corrosion and the importance of were installed under subcontracts in construction projects. A having DOT staff receive training in cathodic protection. At total of 13 structures received cathodic protection under this present, three staff members are experienced and are well- project. From 1989 to 1993, cathodic protection systems versed with cathodic protection technology; they primarily were installed on the decks of 12 bridge structures. In the control the implementation of the technology. In-house- 19961997 time frame, cathodic protection was installed on developed technology and research projects funded by the the caps of one more bridge. All cathodic protection systems FHWA provided them with much of the experience. CTB staff installed under this program are impressed current type with has also received training from NACE educational programs. titanium-mixed metal oxide mesh or ribbon anodes. Funding for the corrosion laboratory is allocated through the Office of Testing and Technology Services, which is a sub- The selection and design of the cathodic protection sys- branch of the Division of Engineering Services. CTB provides tems were performed in-house by the Research Group with its services to the headquarters and the districts. assistance from the FHWA and NACE. The installation spec- ifications were developed by the Research Group in con- The maintenance groups and structure design engineers junction with their consultants and they in turn received input decide on the repair and/or rehabilitation strategies. The design from system material suppliers and installers. The material of the cathodic protection systems, when used, is done by the suppliers provided a manufacturer's representative during CTB. Caltrans does not have any standards; they use the spec- the installation to ensure that the systems were installed in ifications from previous projects and the experience of the staff accordance with the project specifications and requirements. in designing the systems. Also, it does not interact with the cathodic protection industry and has generally used systems Since installation, all systems have been monitored by the developed in-house. Quality control functions are done by in- Research Group and are performing satisfactorily. Although house personnel. Monitoring and maintenance of the cathodic they do not have formally trained personnel, the Research protection systems is performed by CTB. Caltrans believes Group has acquired sufficient skills to monitor and maintain that if better guidelines become available and if its confidence the systems. All bridges included in the study are within a in the newer product is established, it is likely to increase its few hours' drive of ConnDOT offices and site visits are reg- use of the technology. ularly made to monitor and maintain the systems. Connecticut When asked to categorize their experience with the catho- dic protection systems, it stated that "ConnDOT's experience In the 1990s, the Connecticut DOT (ConnDOT) initiated a has been highly satisfactory for corrosion prevention and research study to ascertain the effectiveness of cathodic pro- control."