2018 Volume 56 Issue 12 Pages 1001-1009
More than 20 million centrifugal compaction concrete poles used as support for power distribution lines and communication lines have been installed nationwide in Japan. The authors conducted a study on progress prediction of crack width with the aim of improving the efficiency of inspection of such concrete poles as part of their maintenance. Material testing of centrifugal compaction concrete specimens was carried out and strength characteristics, creep characteristics, and drying shrinkage characteristics were analyzed. In addition, continuous loading was carried out using actual poles, and crack dispersibility, crack width, reinforcement strain, and deflection trends were measured. From these results, we summarized the characteristics of centrifugal compaction concrete for each component of the crack width calculation formula, and we propose a calculation formula simplified for application to inspection work.
