In the preceding researches authors have proposed the seismic upgrading method of an anchor-bolt in an exposed-type column base in the existing old steel buildings and the tension test of the upgraded anchor-bolt showed enough upgrading effect. In this paper an experimental test of exposed-type column base using such upgraded anchor-bolts is performed and upgrading effect is recognized, and it is shown that the exposed-type column bases using such upgraded anchor-bolts could satisfy the rotation capacity demanded in the structural design.
