Abstract
This paper discusses the ultimate strength for the cone type fracture of base concrete from the anchorage of anchor-bolt of exposed-type column base. Nine full-scale specimens of three series were tested to examine the fracture modes and ultimate anchorage strength of exposed-type column base. Based on the test results, the estimation formula of the ultimate anchorage strength for the cone type fracture is proposed considering the contribution of punching shear strength of base concrete, bonding strength of reinforcing bars around anchor-bolts, flexural strength of main reinforcing bars of footing beam and so on. The calculated strengths from the estimation formula agree relatively well with the experimental cone-type fracture strengths.
