Grade Beam Frost Void

[KevinValenta]

What would be a good way to get a frost void under a grade beam?

I'm building a post frame garage using 24"diameter x 36"deep concrete pier footings 8'OC (soil bearing capacity has been checked and pier footings can support 16,956 PSF vs. the load of 12,160 PSF) and Perma-Column's Sturdi-Wall Plus wet set moment resisting brackets to secure the glulam 3-ply 2x6 x 22' high posts.

I would like to connect the piers with a grade beam (vs. pressure treated splash boards on the exterior and interior) to avoid any surface water contacting the Sturdi-Column Plus steel brackets or the bottom of the glulam posts, and provide a concrete vs. wood break between the exterior & interior of the building by means of a min. 8" wide (Perma-Column spec)x 16" high grade beam/stem wall with two Grade 60 horizontal rebars (Perma-Column's spec) but need to protect against frost heave and saw the old thread about creating a void under the grade beam and wondering if there is a cost-effective way to create that.

One idea that comes to mind is corrugated solid wall drainage pipe in two rows of 4" diameter pipe conforming to ASTM F667 specifications that has a stiffness at 5% deflection of 30 psi and impact resistance of 27.5 ft.lbs. at 25 degrees F. With just the cured concrete weighing about 150 LB per cubic ft the 8"x 16" grade beam should weigh about 130 LB per LF not including the nominal weight of the rebar. Would the corrugated drainage pipe create a void effective at isolating the grade beam from frost? If not any other ideas? Thanks.

 

[SWComposites]

Why is this posted in the Disasters forum?

 

[JohnRBaker]

I was asking myself that same question...

John R. Baker, P.E. (ret)
Irvine, CA
Siemens PLM:
UG/NX Museum:

The secret of life is not finding someone to live with
It's finding someone you can't live without

 

[Alistair_Heaton]

Ahead of the game?

Like me designing my barn and doing DIY electrics plus solar and heat pump.

 

[KevinValenta]

Now posted in concrete forum thanks

 

[Brad805]

Its called void form. Available from insulation suppliers.

 

[jayrod12]

I have severe concerns about 3 ply 2x6 posts at 8 feet on centre. I assume these posts also act as the main lateral force resisting system? I.E. there's no shearwall or bracing? I can't imagine a 3 ply 2x6 is sufficient if that is in fact the case.

 

[MotorCity]

Off topic, but a 3' deep pier seems way to shallow to resist any lateral loads from a 22' high post.

 

[hokie66]

When someone quotes numbers like 16956 PSF for a bearing pressure, I know they are not an engineer.

 

[jayrod12]

They're also likely a metric user regularly to understand why that looks weird. It's probably 815 kPa bearing pressure and they just copied whatever google conversion gave them.

EDIT: Upon closer look, that doesn't make sense either unless it's bearing directly on rock. So they probably meant lbs, but don't understand the difference.

 

[JoelTXCive]

Look into Void Forms.......

https://voidform.com/