Lt. Gen. Todd T. Semonite, Army Corps of Engineers commander, sees a barge lock through Chickamauga Lock during a visit to the project in Chattanooga, Tenn., June 7, 2016. The 60-by-360 foot lock has structural problems resulting from alkali aggregate reaction between the alkali in the cement and the rock aggregate, which results in a physical expansion of concrete structures. Even with costly advanced maintenance procedures, the concrete expansion threatens the structural integrity of the lock and limits its life span. (USACE photo by Leon Roberts)

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Keywords: ., chattanooga, chickamauga, chief, corps, district, engineers, gen., lock, lt., nashville, project, replacement, river, semonite, tennessee, todd, usace