Volume 3 (2015) Issue 1 Pages 19-32
High-strength bolted friction-type joints are often used for onsite maintenance and strengthening work for steel bridges. Abrasive blast-cleaning to prepare the surfaces of existing steel members may not be done depending on site conditions. In this paper, slippage tests were carried out for specimens with splice plates coated with inorganic zinc-rich paint on the surface and connected plates with varied surface roughness. The results of the slippage tests showed that the relationship between slip coefficient and surface roughness was linear up to 75 μm thickness of inorganic zinc-rich paint. Furthermore, a design slip coefficient is proposed for inorganic zinc-rich paint with thickness from 50 μm to 150 μm, considering Ra on the surface.