The DFT has a transverse node projection on the upper flange, which is smoothed by cutting the projection at the joint. However, from the viewpoint of simplifying the construction process, a joint type that does not require cutting of the protrusions is desired. Generally, inorganic zinc-rich paint is applied to DFT, but there is concern that the high contact pressure generated by the protrusions may reduce the coefficient of friction. Therefore, a sliding test was conducted to clarify the sliding behavior when inorganic zinc-rich paint is applied. The test results showed a 29% decrease in the slip coefficient due to earlier slippage on the projecting side and increased axial force reduction.
