Weathering Steel Sculpture Base

[H57]

I have been asked to design the framing for a sculpture. The frame is generally welded angles with a steel plate skin. The skin will be weathering steel. The interior support angles are being proposed as A36 painted (except the base angle). My main questions have to do with the base of the sculpture.

1) It has been proposed to use a weathering steel angle base that is bolted to the concrete foundation. As the angle will bear on the concrete and there's no way to ensure water won't get into the sculpture I have left gaps around the perimeter for water to drain. I'm questioning how this weathering steel will perform long term as the base angle. Is there another type of steel that should be used? Or another type of protection?

2) They have asked to use galvanized anchor bolts that are separated from the structure by nylon washers or similar. Is this sufficient to protect the anchor bolts?

 

[bridgebuster]

1) Nothing wrong with using weathering steel as long as you don't create areas where water can accumulate, and, no one cares that the concrete will eventually be covered with rust stains.
2) The nylon washer should serve the purpose.

 

[dhengr]

H57:
Why is the weathering steel skin plate and base angle even needed? If there is no way of preventing water from penetrating the sculpture you are more than likely going to get the rust dripping and staining on the foundation. Maybe you can catch and divert any dripping at the skin and base angle. Can you cover the whole foundation with some of the skin plate? Bolted, galvanized truss systems work really well as weathering power transmission towers, and don’t bleed all over the place. Then no skin plate is needed. These could be welded in sizes which would fit a local galvanizing tank, to minimize field bolting. And, they can have all kinds of short cantilever struts sticking out for attachment to the sculpture. Slope the top of the foundation to drain well to the outside.

 

[JStephen]

I haven't tried it...but seems to me that painting the foundation brown would mostly eliminate the rust-bleeding issue, which is just cosmetic.