抄録
This Paper is intended to study the bond strength between the steel bars which is coated with zinc and aluminium and the concrete, some of which is admixed the Calcium Chloride. The results of persistency will be reported in the nearest future. As the results of these experiments, we found that there are no differences in the bond strength between coated bars and non-corted far, so far as one and four weeks aged specimens. But in case of thirteen weeks aging or more, coated bars are by far higher than non-coated bar. Namely, zinc coated bar, in case of thirteen weeks aged specimen, is 25% higher than non-coated and is 42% higher in four years aged specimen, further more, alminium coated bar, incase of thirteen weeks aged specimen, is 31% higher than non-coated and is 37% higher in four years aged specimen. When the Calcium Chloride has been admixed with concrete, the bond strength of zinc coated bar become higher with the passage of time, but there are no tendency to increase concerning to the aluminium coated bar. The slip of the coated bar at the bond breaking is smaller than that of non-coated bar in the shorter aging. Also, the difference between coated and non-coated bar is decreased with the passage of time. Therefore, the bond strength between the zinc and aluminium coated bars and the concrete as well as the non-coated bar.
