Pavement Construction for GA Aircraft
 

Where would I find information on pavement construction. A local farmer I know, uses a C182 off his own property, his makeshift runway is a graded dirt road down one side. Problem is it becomes very muddy after rain and unuseable. So he wants to seal it with a cape seal. A cape seal is a version of chipseal, where a layer of bitumen is spread on the dirt then a truck lays small gravel in the bitumen which is pressed into the bitumen then allowed to set. The cape seal is a slurry that's laid over the chip seal and provides a smooth surface very much like hotmix asphalt but at 1/4 of the cost.

Question is, for a runway that will only be used maybe 5 times per week, what sort of subgrade and preparation would be required for aircraft up to 3000 kg. the underlaying ground is thick clay type soil that's hard as a rock in summer.

Are light GA aircraft harder on pavements that trucks.

in "Sigh for a Merlin" Alex Henshaw writes about one airfield that he tested Lancasters on which only had HALF the runway paved.

He said people often questioned why half the runway was grass, but he stated that it did the job and saved the taxpayer hundreds of thousands of pounds.

Guptar,
Cateye is on the money, there is plenty of information around on sealed light duty road construction, starting with a proper assessment of the underlying soil types.
Tootle pip!!

Gileraguy, but which half? One end or one side ? It makes a big difference.

Light Aircraft are less damaging to pavements than Trucks except in making tight radius turns. Aircraft are able to completely stop the inside wheel which can cause a very high shear stress. If possibly try to prevent a turn where the inside wheel is stopped. The tires will last longer too. Tractor tires can be quite damaging to pavements so perhaps keep the tractor off the runway.

I suspect that your friend will have a few issues and that cape seal won't work as well as hoped. By the sounds of it the current setup has a lot of clay which turns to mud when it gets wet. While the seal will reduce this it will still occur. When the clay gets wet it will expand and as it dries it will shrink causing crackling of the pavement. Consider improving the soil either by the use of a road base layer or by cement stabilization depending on the conditions.

Drainage is also important. If the runway is slightly elevated with good drainage of water away then it will last longer.

Once is if done make sure that the lose chips are removed to reduce damage to the propeller. A sealed road with loose chips may be much worse than the current clay runway.

A good engineer local to you friend would be able to provide advise specific to the local soil type and available materials.