Airstrip construction cost
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Airstrip construction cost
Can anyone provide rough cost for a 600m private gravel runway to be built from scratch? I understand that there are many variables, just trying to get an idea. Also, any Aus companies that are recommended?
Basically you want to build a 600m piece of road. I'd call your local earthmoving guy. But the issues to consider are:
a) What slope constraints do you want (ie how much dirt do you want to move). If you want it to be within 1% then you might be astonished about how much dirt needs to be moved.
b) What size aircraft do you want to land (ie how think should the crushed rock base be. 300mm is probably typical, but landing a C150 on a padock could get away with a few inches)
c) how weatherproof do you want it, ie how good should the drainage be. This might be one of the higher cost items.
Do you really want gravel? Why not just consider grading a flat surface on grass and making some drainage?
a) What slope constraints do you want (ie how much dirt do you want to move). If you want it to be within 1% then you might be astonished about how much dirt needs to be moved.
b) What size aircraft do you want to land (ie how think should the crushed rock base be. 300mm is probably typical, but landing a C150 on a padock could get away with a few inches)
c) how weatherproof do you want it, ie how good should the drainage be. This might be one of the higher cost items.
Do you really want gravel? Why not just consider grading a flat surface on grass and making some drainage?
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Anywhere from $5-10k (you have a mate with a truck and a grader, just buy the gravel at a good price) to however much you want to make it. 
Seems to me anyone who can make a gravel driveway for a rural property should be able to make you a bit of a runway.
Mine is nothing more than the already hard sandy soil smoothed out a bit. Steel mesh (like they put in concrete floors) weighed down and dragged behind a 4x4 works well. We'll see how it goes when the rains come - first year here...
Seems to me anyone who can make a gravel driveway for a rural property should be able to make you a bit of a runway.
Mine is nothing more than the already hard sandy soil smoothed out a bit. Steel mesh (like they put in concrete floors) weighed down and dragged behind a 4x4 works well. We'll see how it goes when the rains come - first year here...
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strip construction.
have a talk to the Jindabyne Aero Club. Their recent upgrade to the strip looks pretty good and uses the compacted gravel method.
The other option is to do cement or lime stabilised which also works well for even medium weight aircraft. Always talk to the local council as they know the local soil types and which system works the best. They will probably have a jetpatcher which can reinforce your runup areas fairly cheaply.
Don't leave loose gravel on the surface as it knackers the prop.
Catseye
The other option is to do cement or lime stabilised which also works well for even medium weight aircraft. Always talk to the local council as they know the local soil types and which system works the best. They will probably have a jetpatcher which can reinforce your runup areas fairly cheaply.
Don't leave loose gravel on the surface as it knackers the prop.
Catseye
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Mine is nothing more than the already hard sandy soil smoothed out a bit. Steel mesh (like they put in concrete floors) weighed down and dragged behind a 4x4 works well. We'll see how it goes when the rains come - first year here...
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Does anyone have a reference book online for how a runway is constructed. was just wondering the difference in depth between a run way for 2000kg aircraft v 50,ooo kg aircraft and say an international A380 runway.
Interestingly I worked on a runway project on 16R at YSSY some years ago. The saw cutter on the project said they must have used some damn good asphalt when it was laid in the mid 70's as it was as hard as granite and he was going expensive diamond tipped drill bits at 10 x the normal rate.
Interestingly I worked on a runway project on 16R at YSSY some years ago. The saw cutter on the project said they must have used some damn good asphalt when it was laid in the mid 70's as it was as hard as granite and he was going expensive diamond tipped drill bits at 10 x the normal rate.
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nomorecatering
If you go to the FAA home page and follow the airports tab, drill down to pavement design programs and you will find a page full with several programs that utilise the ACN/PCN principles and allow multiple construction material/sub-base/surfacing and traffic mix scenarios's. Pretty much the bible some of this stuff.
Last edited by Fieldmouse; 20th Mar 2013 at 20:33.
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Once you've found the money to pay for the construction cost, here are three practical things to check:
Rough surface
Soft, wet surface
Takeoff gradient.
Roughness is tested by driving over it in a laden 4wd or utility at 75/80 km/hr. What I do is use the personal car of the local manager/owner - it focuses their mind wonderfully on the strip condition when they have to drive it in their own vehicle.
Soft, wet surface is tested by driving over it in a zig-zag pattern at very slow speed and looking for wheelruts more than 25mm which indicate soft areas. Maybe give a couple of spots a dig with a crowbar to check that it is not just a hard dry crust over a soft base (absolutely essential if you're in an old lake bed or there are white salty patches around). If in doubt, borrow a 5 tonne truck and drive the runway using that. If it doesn't get bogged, your 2 tonne aircraft shouldn't either.
The takeoff gradient can occasionally be tricky if the ground is generally sloping. You're looking for maximum 5% clear gradient (which is about 3 degrees). I've been caught just the once where a strip approach looked reasonably clear to the naked eye, but the whole landscape was sloping and the actual takeoff gradient was 11%. If the aircraft had ever got off the ground, it would have hit the rising ground further along.
The only way to be sure is to use a small clinometer (costs about US$60), but you can make your own. Got this cute method from Elanora primary school. You will need a drinking straw, a semicircle of cardboard, some tape, a piece of cotton and a weight. Use a protractor to mark the cardboard into degrees from 90 to 0 to 90 with zero at the bottom of the curve. Tape the straw along the straight edge of the semicircle.Tape the cotton to the centre of the straight edge of the semicircle. Attach a weight to the cotton.
Rough surface
Soft, wet surface
Takeoff gradient.
Roughness is tested by driving over it in a laden 4wd or utility at 75/80 km/hr. What I do is use the personal car of the local manager/owner - it focuses their mind wonderfully on the strip condition when they have to drive it in their own vehicle.
Soft, wet surface is tested by driving over it in a zig-zag pattern at very slow speed and looking for wheelruts more than 25mm which indicate soft areas. Maybe give a couple of spots a dig with a crowbar to check that it is not just a hard dry crust over a soft base (absolutely essential if you're in an old lake bed or there are white salty patches around). If in doubt, borrow a 5 tonne truck and drive the runway using that. If it doesn't get bogged, your 2 tonne aircraft shouldn't either.
The takeoff gradient can occasionally be tricky if the ground is generally sloping. You're looking for maximum 5% clear gradient (which is about 3 degrees). I've been caught just the once where a strip approach looked reasonably clear to the naked eye, but the whole landscape was sloping and the actual takeoff gradient was 11%. If the aircraft had ever got off the ground, it would have hit the rising ground further along.
The only way to be sure is to use a small clinometer (costs about US$60), but you can make your own. Got this cute method from Elanora primary school. You will need a drinking straw, a semicircle of cardboard, some tape, a piece of cotton and a weight. Use a protractor to mark the cardboard into degrees from 90 to 0 to 90 with zero at the bottom of the curve. Tape the straw along the straight edge of the semicircle.Tape the cotton to the centre of the straight edge of the semicircle. Attach a weight to the cotton.
Last edited by OverRun; 9th Apr 2013 at 00:49. Reason: Adding the clinometer picture
I presume these thicknesses are concrete?
I'm surprised you would do as little as 75mm for a Cessna. I thought driveways / garages were typically 100mm and frequently 125mm. I had also presumed that 182 & heavier aircraft have higher contact pressures than cars (similar weight, but 3 heels not 4 and smaller wheels) which might require better pavement strength than driveways.
I'm surprised you would do as little as 75mm for a Cessna. I thought driveways / garages were typically 100mm and frequently 125mm. I had also presumed that 182 & heavier aircraft have higher contact pressures than cars (similar weight, but 3 heels not 4 and smaller wheels) which might require better pavement strength than driveways.
Had a 800 meter driveway done from scratch, approx 3.5 wide and 6 inches deep. To save money a dam was dug and the excavated material was used for the road.
Suitable gravelly clay, set like concrete.
One 20 T excavator, one small excavator with blade at front, one single axle tipper, 2 men, 2.5 days. Total cost $ 5000.
Suitable gravelly clay, set like concrete.
One 20 T excavator, one small excavator with blade at front, one single axle tipper, 2 men, 2.5 days. Total cost $ 5000.
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Old Akro, the thicknesses are just total pavement thickness – in the case of the Cessna, it is all gravel and assumes that the natural ground is not too weak or in a bog. In the case of the A380, it is 125mm hot mix asphalt plus 250mm cement stabilised crushed rock plus layers of crushed rock and gravel. The life of the Cessna runway is a bit limited because gravel erodes by up to 25mm a year (wind, sun, rain, abrasion etc), so some people would put an extra 25-50mm down at the start to allow for a couple of years of erosion.
If you wanted to put an engineered surface (bitumen or concrete) on top of the gravel from the start for the Cessna, then it is much less tolerant of soil movement and pavement deflection and you would make the gravel a bit thicker.
The tyre pressures and weights of the Cessna are almost too small to count in pavement structural terms.
If you wanted to put an engineered surface (bitumen or concrete) on top of the gravel from the start for the Cessna, then it is much less tolerant of soil movement and pavement deflection and you would make the gravel a bit thicker.
The tyre pressures and weights of the Cessna are almost too small to count in pavement structural terms.
Over Run
Late last year I was in William Creek with Trevor Wright while he was trying reconstituted asphalt as a hangar surface. It was dramatically cheaper than other alternatives. But I have been wondering about using it for a hangar apron. Do you have any experience with this?
Late last year I was in William Creek with Trevor Wright while he was trying reconstituted asphalt as a hangar surface. It was dramatically cheaper than other alternatives. But I have been wondering about using it for a hangar apron. Do you have any experience with this?
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Old Akro,
I reckon it would work for the apron as well as the hangar floor. It might eventually need to be surfaced with a bitumen seal on the apron if there are problems with erosion, loose stones and propwash, but I would be tempted to try it first and see.
Reconstituted asphalt is old asphalt which has been milled up by a road builder/council. Asphalt is a mixture of 95% graded stone and 5% bitumen. The 'recycled asphalt pavement' or "RAP" ends up looking like a dirty crushed rock with some large sized stones (20-40mm) in it. It's normally hauled back to the asphalt plant or council depot for future recycling, and if you can get it delivered cheaply, it can be better than gravel.
Cheers, OverRun
When used as an apron, carpark or footpath, it packs down pretty easily and acts like a crushed rock. But over time the old bitumen in the recycled asphalt sort of re-activates a bit and starts to re-bind the graded stone. Hot weather softens the old bitumen which helps. Fuel and oil spills aren't really much of a problem because they help to re-activate the bitumen as well. After a year or two, it can set pretty hard and does not erode easily, and usually goes a gray colour. It will never be concrete, but it is a lot better than dirt and better than gravel. I have seen a lot of it used to build carparks and backstreets when funds are tight.
There is a variant which is not common, and that is to mix through 1.5-2% bitumen emulsion (maybe diluted with water a bit as well) before compaction, and then you get poor man's asphalt from the very start. Adrian Bergh was one of the grandfathers of this type of thing, and he used to come back after the initial rolling, loosen the top 25mm and then mix an extra 1% bitumen emulsion into that top 25mm (also diluted with water a bit as well) and recompact, and then you REALLY get the poor man's asphalt which should also be erosion proof. Pretty messy work though.
Because RAP is 95% stone, it is inherently strong, and if you eventually have to put a bitumen sealed surface on top because of erosion problems, the RAP is already a great basecourse and you can simply bitumen seal on top. I would make sure that you have 100mm depth of the RAP before you put the bitumen seal on though, because once you have bitumen sealed it then you can't later reshape or regrade any ruts or roughness.
Incidentally that is why gravel roads and runways can have thin pavements – they only need have a life of a few months or maybe a year or two, and they can rut and corrugate and get rough, and then the grader comes back to reshape them. If I get my driveway built with a nice asphalt surface, I want it to last 20 years in perfect condition without being touched, and so then I need a thicker pavement.
I reckon it would work for the apron as well as the hangar floor. It might eventually need to be surfaced with a bitumen seal on the apron if there are problems with erosion, loose stones and propwash, but I would be tempted to try it first and see.
Reconstituted asphalt is old asphalt which has been milled up by a road builder/council. Asphalt is a mixture of 95% graded stone and 5% bitumen. The 'recycled asphalt pavement' or "RAP" ends up looking like a dirty crushed rock with some large sized stones (20-40mm) in it. It's normally hauled back to the asphalt plant or council depot for future recycling, and if you can get it delivered cheaply, it can be better than gravel.
Cheers, OverRun
When used as an apron, carpark or footpath, it packs down pretty easily and acts like a crushed rock. But over time the old bitumen in the recycled asphalt sort of re-activates a bit and starts to re-bind the graded stone. Hot weather softens the old bitumen which helps. Fuel and oil spills aren't really much of a problem because they help to re-activate the bitumen as well. After a year or two, it can set pretty hard and does not erode easily, and usually goes a gray colour. It will never be concrete, but it is a lot better than dirt and better than gravel. I have seen a lot of it used to build carparks and backstreets when funds are tight.
There is a variant which is not common, and that is to mix through 1.5-2% bitumen emulsion (maybe diluted with water a bit as well) before compaction, and then you get poor man's asphalt from the very start. Adrian Bergh was one of the grandfathers of this type of thing, and he used to come back after the initial rolling, loosen the top 25mm and then mix an extra 1% bitumen emulsion into that top 25mm (also diluted with water a bit as well) and recompact, and then you REALLY get the poor man's asphalt which should also be erosion proof. Pretty messy work though.
Because RAP is 95% stone, it is inherently strong, and if you eventually have to put a bitumen sealed surface on top because of erosion problems, the RAP is already a great basecourse and you can simply bitumen seal on top. I would make sure that you have 100mm depth of the RAP before you put the bitumen seal on though, because once you have bitumen sealed it then you can't later reshape or regrade any ruts or roughness.
Incidentally that is why gravel roads and runways can have thin pavements – they only need have a life of a few months or maybe a year or two, and they can rut and corrugate and get rough, and then the grader comes back to reshape them. If I get my driveway built with a nice asphalt surface, I want it to last 20 years in perfect condition without being touched, and so then I need a thicker pavement.
Trevor used a light spray of Jet A1 to get the asphalt particles to "recombine", although I believe that it should correctly be the bitumen emulsion. It looked like it could be pretty good, but it was still very fresh and soft in places when I saw it.
Thanks for your comments
Thanks for your comments
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Jet A1 would soften and re-activate the old bitumen, and should stay in the mix for a few months to help it all pack down. It might be better and less soft with a mix of Jet A1 and diesel, and even add a bit of old engine oil in the brew.
The RAP however is still a little bit short on bitumen compared to fresh asphalt, which is why it is slightly friable. The bitumen emulsion adds the missing bit of bitumen.
Cheers,
OverRun
The RAP however is still a little bit short on bitumen compared to fresh asphalt, which is why it is slightly friable. The bitumen emulsion adds the missing bit of bitumen.
Cheers,
OverRun
