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| Performance evaluation of prestressed anchors embedded in old Fengman dam after nearly 30 years service |
| WANG Yujie1，YIN Tao1，2，SUN Xingsong1，ZHAO Yufei1#br# |
| (1. State Key Laboratory of Simulation and Regulation of Water Cycle in River Basin，China Institute of Water Resources and Hydropower Research，Beijing 100038，China；2. College of Civil and Transportation Engineering，Hohai University，Nanjing，Jiangsu 210000，China) |
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Abstract Since the prestressed anchors were widely used in concrete dam reinforcement，their long-term durability has been increasingly concerned. To validate the durability of the prestressed anchors in the high alkaline environment of dam bodies，the field exhumation of anchor cables which have served for nearly 30 years in old Fengman dam was performed during the demolition progress of the dam，and the anchor samples were collected and tested in the laboratory for evaluating the durability performance of the prestressed anchors in Fengman old dam including the corrosion appearance and corrosion degree，and the chemical and mechanical properties. The electrochemical test was conducted to analyze the anchor corrosion resistance and to assess the causes of the anchor corrosion. The main conclusions are summarized as follows：(1) the average corrosion rate of the bonded prestressed anchors in service for nearly 30 years is higher than 2%，which indicates that the alkaline environment in concrete dams can not effectively inhibit the corrosion of the prestressed anchors. (2) The unbonded anchors in the dam body have better performance in corrosion resistance than the bonded anchors，and (3) after nearly 30 years¢ service，the elastic modulus of 51.3% anchor samples is below the limit of “the Steel Strand for Prestressed Concrete”(GB/T 5224—2014).
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2022, Vol. 41 
