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C AT H O D I C P R O T E C T I O N lines. Also, application of a coating on the buried portion of the concrete pole increases the electrical resistance to the ground and decreases the probability of the occurrence of stray AC. In the study area, large stones were used for mounting the concrete poles (Figure 5[a]). In such conditions, there was considerable empty space between the stone, which could fll with rain water. This caused the buried portion of the pole to be saturated with water, which decreased electrical resistance and increased the probability of stray AC. To solve this problem, the concrete poles were mounted in the ground, according to Figure 5(b). In this condition, a concrete mix of 350 kg/m3 Portland cement, 1,145 kg/m3 aggregate (<5 mm), 199 kg/ m3 aggregate (5 to 10 mm), 558 kg/m3 aggregate (10 to 20 mm), 2% super plasticizer, 10% silica fume, and a water/ cement ratio of 0.45 was used to mount the poles. Conclusions All factors that increase the electrical resistance of concrete power poles decrease stray AC. Therefore, the use of non-metal cross arms, increased creepage distance of insulators, increased water drainage in areas where concrete poles are mounted, and application of a coating on the buried portion of the concrete pole can improve resistance of concrete poles to stray AC. High-strength concretes with a low volume of capillary pores are suitable for power poles. Low-strength concretes with a high volume of capillary pores have a high water absorption in rain, one of the reasons that stray AC occurs. After implementing all these modifcations, stray AC problems were eliminated in the area of investigation. References 1 Appalachian Underground Corrosion Short Course (AUCSC) Advance course, West Virginia University, Morgantown, West Virginia, 2009. NACE International, Vol. 52, No. 5 2 L. Bertolini, B. Elsener, Pietro Pedeferri, R. Polder, Corrosion of Steel in Concrete (Weinheim, Germany: Wiley-VchVerlag GmbH & Co. KGaA, 2004). 3 R. Vedalakshmi, R. Renugha, Devi Bosco, Emmanuel N. Palaniswamy, "Determination of Diffusion Coeffcient of Chloride in Concrete: an Electrochemical Impedance Spectroscopic Approach," Materials and Structures 41 (2008): pp. 1,315-1,326. 4 L.L. Grigsby, Electric Power Engineering Handbook, Second Ed. (London, U.K.: Taylor & Francis Group, 2006). AbbAs AgHAjANI is a Ph.D. student of the Dept. of Materials Engineering, Isfahan University of Technology (IUT), 8415683111, Iran. He is also on the faculty of the subsea R&D; Center of IUT, e-mail: aghajani@cc.iut.ac.ir. He has conducted research at the university for 19 years and has published more than 25 project reports in the felds of stray AC and direct current in concrete, cathodic protection, and coatings. He has also published more than 30 papers, eight journal articles, and one book. MOHAMMED AlI gOlOzAR is on the faculty of IUT, Materials Engineering Dept., e-mail: golozar@cc.iut. ac.ir. He has taught in the areas of corrosion, heat treatment, and physical metallurgy for 32 years, and has published 80 journal articles, 200 conference papers, and six books. A. sAATCHI is a professor at the IUT Materials Engineering Dept., e-mail: asaatchi@cc.iut.ac.ir. He teaches and conducts research in the feld of corrosion. He was named a National Distinguished Professor in 2003. He has published more than 80 papers and eight books, founded the Iranian Corrosion Association (ICA), and served on the ICA board of Managers for four years. He has a Ph.D. in materials science and engineering from the Ohio state University. KyvAN RAEIssI is on the faculty of the IUT Materials Engineering Dept., e-mail: k_raeissi@cc.iut.ac.ir. He has spent the last nine years teaching advanced electrochemistry, advanced corrosion, corrosion inhibitors, corrosion in welding joints, paint and converting coatings, and pyrometallurgy. He has published 63 journal articles and more than 100 conference papers. sAEID sHAbANI is on the faculty of IUT, subsea R&D; Center, e-mail: sshabani@cc.iut.ac.ir. He has conducted research in marine environments for 21 years. He is head of the Material and structure group and has published more than 18 marine project reports and 15 conference papers. MUsTAfA URgEN is a professor at ITU, Dept. of Metallurgical and Materials Engineering, Maslak Campus 34469, Istanbul, Turkey, e-mail: urgen@itu. edu.tr. He teaches and conducts research and development in the area of surface treatments. He has published more than 70 papers. He is an active member of the Turkish Corrosion Association at the national and international levels. May 2013 MATERIALS PERFORMANCE 39