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45 CONCLUSIONS Based on the results of the survey and the discussions presented in this report the following conclusions can be drawn: 1. Agencies that have successfully implemented cathodic protection technology have experienced a reduction in the frequency and cost of bridge maintenance and an increase in the service life of their bridge structures. To accomplish this they had to acquire a good understand- ing of the technology and expertise in the technology. 2. Cathodic protection is accepted as a viable corrosion control technology by some agencies. However, the use of this technology is limited. 3. The use of cathodic protection technology has been declining. From 1970 to 1989 approximately 275 bridges were outfitted with cathodic protection sys- tems; in the next 20 years, almost 240 bridges had been added to the inventory of 21 agencies. However, there is some promise of growth during the next 5 years. The technology is actively used only by the states of Florida, Missouri, and Oregon and the provinces of Alberta, New Brunswick, and Ontario. 4. The primary disadvantages to the use of cathodic protection technology are the initial cost and the bur- den of monitoring and maintaining the systems. Past disappointing experience has also slowed the implementation of this technology. Many of the dis- appointing experiences resulted from the use of the previous generation of materials and inappropriate implementation of the technology. In addition, most agencies do not have the resources to implement the cathodic protection technology and have chosen not to make a commitment toward developing such resources. 5. Galvanic cathodic protection is becoming more attrac- tive than impressed current owing to lower monitoring and maintenance requirements. Future research and development might be focused in this direction. 6. Competition and innovation are required in the indus- try to improve the quality of products and services. 7. Corrosion is, at a minimum, a moderate problem for the majority of the departments of transportation in North America, although for some it is a severe problem. Sev- eral agencies that are expected to experience severe cor- rosion problems did not respond to the survey. In many states and provinces where cathodic protection would be an appropriate technology to implement, deicing salt usage is sufficiently high, more than 5 tons per lane- mile per year. For coastal states and provinces, marine exposure is also a significant cause of corrosion on rein- forced concrete structures. 8. A majority of agencies have standard procedures, pro- tocols, or methodologies for conducting corrosion condition evaluations, analyzing the data, and selecting alternatives. The test methods used by the agencies in corrosion condition evaluations appear to be adequate; however, no information on the quality of these evalu- ations is available. REQUIREMENTS FOR IMPLEMENTATION OF CATHODIC PROTECTION TECHNOLOGY Based on the results of the survey and the literature review, the following would improve the quality of the implementa- tion and increase the confidence in the technology, thereby resulting in an increase in its use. 1. Dissemination of information on the cost benefits of using cathodic protection systems and success stories from user agencies by either the National Association of Corrosion Engineers (NACE) or FHWA, or both. 2. It would be useful if training in the technology were offered by a national program such as NACE or the National Highway Institute. 3. Development of standards and specifications for selec- tion, design, installation, and monitoring and mainte- nance of the systems. It is important that user agencies adopt a standardized protocol for corrosion condition evaluation, analysis of data, selection of alternatives, design of the system, specifications for installation, and protocols for monitoring and maintenance. 4. Departments of transportation might acquire at least one individual, if not more, with expertise in cathodic protection technology. Although the individual may not be able to perform all of the necessary tasks, he or she would be knowledgeable enough to supervise others or manage consultants. It would be desirable for the individual to possess the NACE Cathodic Protection Specialist Certification. 5. It is best to use anode materials and configurations that are prequalified, meet a certain performance and CHAPTER SEVEN CONCLUSIONS AND FUTURE RESEARCH NEEDS
durability criteria, and have a documented history of field performance, unless an experimental system is being installed. 6. Quality control and assurance may be provided by either the agency or an independent third party with trained and qualified personnel who have experience in similar systems. 7. Each agency might develop a database to track and inventory all cathodic protection systems. This database can also be used to track the status of the system and manage monitoring and maintenance program. 46 FUTURE RESEARCH NEEDS 1. Research and development of newer anode material may help to provide a larger selection for the user agencies and expand the application of the technology. Development of more effective and efficient galvanic anodes would increase the acceptance of the technol- ogy as it requires less monitoring and maintenance. Also, an increase in the service life of galvanic anodes is desirable. 2. Better information is needed on life-cycle costs and ini- tial costs, in comparison with other corrosion treatments.
