Hangar concrete specs

[Yenn]

As i said previously most big slabs are poured in smaller sections. This makes life easy because you are not trying to finish one big section in a hurry. Another advantage is that you box up a couple of sections, pour them and then you have two poured slabs which saves boxing that area. Pour it in a chequerboard fashion and the boxing out is much lessened.

If you are going to supervise it yourself, be warned. The people doing the job will listen to you and do what you want, but if they see you don't know what you are talking about, you could get taken for a ride. Believe me I have had to supervise many jobs and when I wasn't on top of the job, it was safer to keep quiet or even admit that i didn't know enough, than try to push things. Better to be quiet and thought a fool, than open your mouth and dispel all doubt.

Ready mix concrete suppliers have been lousy in the past, but I am hopeful that they are more professional nowadays. Concrete finishers will often want to add water to increase the slump, which gives the readymix supplier an out as to concrete strength. Adding water reduces the strength, but you need workability to place it.

[RFguy]

"Better to be quiet and thought a fool, than open your mouth and dispel all doubt."
love it.

hangar is gettign closer.

 

[facthunter]

That's Incredribble.  Nev

[Ian]

What design/size hangar and door combination did you choose and would you care to share the budget? 

[RFguy]

Hi Ian

18x24m, 5.5m to gutter. There is a 25m block width (50m deep). this leaves 25-18 = 7m only for outriggers for doors

 

Preferred option is on site poured and tilt up  concrete, but I cant seem to get the proposed contractors mind on the job, the has too many late running jobs right now due to wet and boggy condix. they can do four tracks. 

 

short listed shed kit supplier only does two row doors.  I have specified that I only need 14.5m open to one side at any one time,  so the two track solution is 3.4m outriggers, and 6 x 3m doors . three doors on each track  so three are pushed over on two tracks to one side and I get a 15m opening one side. push doors over the other side, I get a 15m opening the other side. Up the middle, that's only 12m opening. But the intention is only two active planes one in each side of the front part of the hangar. airplane projects can go down the back. workshop+mezzanine  in the rear half. 

This is not a 'club hangar', so is purpose built. Ideally, Cowra would have T access hangars.
 

commercial details by PM

Glen.

 

 

 

 

 

 

 

Edited December 10, 2022 by RFguy

[facthunter]

The "outriggers " for the doors can provide  extra IF needed bracing for the open doors end.   Nev

[Ian]

4 hours ago, RFguy said:

Preferred option is on site poured and tilt up  concrete, but I cant seem to get the proposed contractors mind on the job, the has too many late running jobs right now due to wet and boggy condix. they can do four tracks. 

I worked on a number of tilt up concrete construction jobs while I was a uni student and really liked it as a building process. It was never mm accurate and there was lots of optimistic packing when the slabs were tilted. However the sites have aged better than I have over the intervening decades.

I'm a bit less enamoured by concrete at the moment just because I've become a bit more worried about CO2 but there are a lot of pros. Maybe there's a grant somewhere for geopolymer using volcanic tuff. https://www.aph.gov.au/DocumentStore.ashx?id=a27746a7-775e-45c9-957a-e8ba0d2e636f&subId=565096

 

I was playing around recently trying to figure out if you could build the old style hangars cost effectively using glulam arches. A glumlam arch using 10MPa laminates gives about a 50:1 span capability. Standard corrugated iron has a minimum spring curve radius of about 12m so skinning uses standard materials and your height is about 6.5m. Doors remain an issue however at least you get to use some of the area closer to the boundary of your site.

 

 

 

[facthunter]

You can roll corrugated iron to much smaller radii for Bull nosed verandahs etc.  Nev

[Ian]

Yes but that requires a custom roll and $$. Standard roofing iron is suitable for a 12m bend. Some types will do 8m without artefacts.

[RFguy]

At Cowra, there are several hangars new hangars being built , one large one being built right now (I know because I see the DAs , as an adjacent land owner) . there might be a bit of room shortly. 

Edited December 10, 2022 by RFguy

[facthunter]

Expansion is a problem with single sheen and curved.  Nev

[Ian]

3 minutes ago, facthunter said:

Expansion is a problem with single sheen and curved.  Nev

Not sure what you meant. Arches extend easily in along their axis, changing the span is difficult, however gabled rooves suffer from the same limitation. Is it likely that you're going to buy the neighbouring block and extend, and have a neighbour willing to sell? Is it simpler to just buy a bigger site?

[RFguy]

I am 2nd on the new 'taxiway'.. club is next door, Trevor is on my right . 

[facthunter]

The continuous sheet wants to lift of the structure when it gets hot in the sun.  Nev

[Carbon Canary]

Are there any round hangars with rotating floors in Australia ?

I haven’t seen any here but there are plenty in Europe.
Great way to virtually eliminate hangar rash in a shared hangar.  I imagine the $$ to build would be substantially higher though.

[RFguy]

Unfortunately the council didnt plan the blocks for T hangars , either.

 

ANyway, now can consider the merits of concrete tilt up versus steel. 

 

[Bruce Tuncks]

Steel ( ie a shed) should be the cheapest. Commercial sheds are about twice the materials cost, but they include specially formed bits. I've done " back to back" farm sheds which are as strong. If you do this, don't exceed the spans as shown by a commercial job, but I don't advise an inexperienced guy to go this way. You really need an engineer to check the design and this will ruin the savings.

By all means get a quote from a tilt-slab guy before you sign up tho. Personally, I would avoid a tilt-slab but then I have no experience with them.

My hangar here( now used as just a shed) only had a 2" floor slab. But it did have plastic underneath . I did it in 2 parts....  first, the end-wall bits and the center bit, both about 300mm wide. Then the remaining bits were filled and screeded off. there was the cheapest reinforcing steel in there too,

So what if a load causes tiny cracks? these will mainly be on the underside and will not matter.

 

If you neglect Jab 7252's advice about plastic, you may create a nasty wet environment for your plane.

The sub-slab soil preparation is important too. A road-base would be good, 150mm deep and rubble well compacted down .

 

[Yenn]

One of the reasons that slabs have plastic underneath is to stop water from the concrete mix being drawn out of the mix.

I saw an ingenious way to build a big span, using steel frames of hollow square or rectangular steel, with a top member that that is longer than the bottom member and sloped vertical members. The top members of multiple frames are hinged together and a steel wire rope is run through the bottom members. This is tightened, making the frames form an arch. It was used for hangars.

g

[Yenn]

The. Problem with tilt up construction is that you have to be careful with the loads on. The thin panel when you lift it up. There are special cast steel lifting lugs which you can cast in, but there is still the loads to work out.

[Bruce Tuncks]

Yenn, it is not just the moisture from the concrete. You can have a hydrologic cycle in a shed, with the rain condensing on the inner steel sheet and the moisture source being the earth. I have actually seen this happen. The poor plane owner was scratching his head trying to work out why his asi was half  full of water.

[facthunter]

Rising damp caused by Osmosis.. Nev

[Kyle Communications]

Hangars are bloody expensive now. The tilt slab construction walls etc with a steel roof type of light idustrial building construction now...is that cheaper than th traditional style of hangar build?. I havent kept up with the slab style stuff  but I did get a couple of quotes for normal stle hangars and they are way expensive now with the steel prices

 

[RFguy]

The concrete  on site pour and tilt up  is competitive with the steel- (after the steel prices went  up).  I think there is 15 tons of steel in my steel hangar build proposal . plus roller doors, PA doors, insulation blankets, door hardware.   The concrete wins on the labour on big sheds where the steel assembly labour is significant.  The concrete is nice for insulation- to a point- hangars are not well sealed as they spend a bit of time with the doors open. The concrete walls , will go to the mean daily temp , most likely. This the concrete actually needs a insulation layer on the outside - that's the best construction for thermal control- just like dumb Brick veneer homes away from the coast - they have the bricks on the wrong side of the wall for thermal control- needs bricks on the  inside.....
where as the steel building the temp will go up and down like a yoyo, well not so much the slab does a fairly good job of limiting the peak to peak.  so add more thermal mass in the form of concrete walls the peak to peak narrows .  so at cowra, the tilt up concrete  probably goes to about  june-july-august about 9 deg C , and peak summer probably a comfortable 24C .  The steel though can have a few windows easily popped in for the mezzanine n etc and other areas  as things change. certainly they can be poured with the gaps in the tilt up, more complex though.  

[Kyle Communications]

I asked a question about slab walls on here and literally 30 mins later up on my facebook feed comes this  https://riseproducts.com/  It makes you wonder doesnt it about how in depth the monitoring of what we say and look at is monitored

 

I havent seen this stuff before at all. I have to say its a pretty neat idea but dont know the costs

 

 

 

 

[facthunter]

They know everything you do. Talk near your phone even though it's not turned on and ads will turn up on your computer screen within seconds. Nev