Guardrail post connection to concrete slab

[bnickeson]

We are designing a galvanized guardrail that runs along the edge of a large waste water treatment basin. For the most part, the guardrail is to be mounted to a 6" thick cast-in-place concrete slab edge, and we are looking for options of how to connect the vertical rail posts to the slab. Since this is outdoors in an area that can experience some cold winters and hot summers, core drilling a hole to grout in the rail posts isn't an option. We would also prefer not to have to weld galvanized steel since there are so many posts to be installed, so that kind of tosses out the cast-in embed idea I typically like to use with the rail posts welded onto the embed.

I have looked at options for both a side-mounted connection and top-mounted connection, either are possible. However, the side-mounted connection would be difficult since the slab is only 6" thick. It makes the anchorage under design moments almost impossible to get to work. It seems our best option is to post-install a bearing plate and socket by anchoring to the top of the slab using screw anchors or expansion anchors. However, due to the huge number of rail posts required, this option is very expensive and labor intensive.

Has anyone here used a product in a situation like this before that they've had good luck with? Any suggestions of details that would provide at least some tolerance/flexibility without the use of welds? I'd love to be able to use cast-in embeds in some fashion but I can't find anything that would give any construction tolerance without welding.

Thanks.

 

[Bagman2524]

This tread comes up quite a bit.

http://www.eng-tips.com/search.cfm?pid=0&action=Search&q=guardrail+posts

 

[bnickeson]

I've gone through most of those and there weren't really any that could be applied to this case. Most deal with the loads and not the connection itself.

 

[bridgebuster]

Is the slab resting on grade or is it supported on structure?

 

[bnickeson]

It's a cantilevered T-slab well above grade. Meaning the slab is about 4'-0" wide and there is a structural CIP wall that forms the stem.

JAE here believes that the rail post in a grouted sleeve will work OK despite the extreme weather environments. I know in other threads I've read on here that some discourage this a freeze-thaw cycle could negatively impact the grout's integrity. Does anyone else have any thoughts on this? It would certainly be the simplest idea.

 

[SAIL3]

could use cast-in-place base pl with studs below and 4 AB's on top...these could be welded or thru bolts...then add a base pl with oversize holes to the posts and bolt in field...add hairpin reinf to slab @ studs if needed..