Concrete Apron Specifications

Individual site conditions can also have an impact on the actual specifications used, as can the quality of the aggregates used etc etc!! 😀

There used to be a complete Internet ‘fan site’ for WW2 concrete, but a quick Google has failed to turn it up.

Moggy

Many moons ago I was involved in constructing an airfield spec concrete pan on Foulness Island for the MOD. It was next to a similar pan with a great big bomb crater in it. The plan was for our new pan to fully cure and have a year or so of weathering then they were going to do the same thing all over again…:rolleyes: With the area being below sea level and very boggy, every time any construction machinery (read bulldozer) trundled past, the adjacent area rose from the dispersed pressure! And all the time we were there, they were firing these “Stalin’s organ” type rockets overhead. When things kicked off in the Gulf in 1991 lo and behold what was on the telly daily on CNN, the very same rocket launchers with their distinctive screech!

Calling all historic aviation enthusiasts who are also closet concrete connoisseurs.

A question for thee: How strong is the concrete used on airfield aprons – those that accommodate aircraft larger than the Nimrod or Sentry E3? I reckon gone the days when 6in of non-reinforced poured concrete was sufficient. Is there a industry recognised standard, and can you use a lesser grade of concrete for stationery aircraft?

There’s two, one for Mil and one for Civil. Mil has extra requirement for VSTOL jet blast etc., and more fuel spillage resistance I think….?

As for civvie, from memory….at LHR, it was something like

250mm thick base lime and cemet stabilised subgrade, and then
150mm thick granular subgrade, then
150mm lean concrete mix, and then finally
450mm thick PQ (Pavement Quality) concrete with ft of 6.0 N/mm2

All with a max 6m x 6m jointed crack bay.

It’s been a while though since I worked on this stuff though, so may have changed.

RAF AM ‘Works’ gave the full requirements for hard surfaces on wartime military airfields.
It is fairly complex these days there are different strengths for different areas, ie thresholds and turning areas are stronger as they have to resist the weight longer, while the runway itself isn’t comparatively that thick or as strong. Here at St Athan the VC-10s can only hold at certain points.
If you can wait a week or so I can find the CAP and JSP requirements.
There was a woopsie at St Mawgan where a Virgin A340 was in for circuit training, it decided to land an taxy for a crew change and taxied over an area that officially wasn’t strong enough for it (though physically it was ok) which was realised afterwards.

There is also the subject of aircraft footprint and pressure on the surface which has to be considered aswel.

I remember a trip in a tri-motor at brize when on start up it ripped up half the concrete on one of the remote stands, woops!

Here’s a giggle – the SAC Apron at Elvington is approximely 9ft thick, reinforced AND has underground fueling pipes.

Eshott’s runway appears to have a top layer of tarmac approx 4″ thick, then a hardcore layer for a couple of feet…. but it could be thicker…

Certainly not at Winthorpe – many happy ‘hours’ with a pneumatic drill to put in ‘few’ fence posts; if only the concrete had been 6 inches thick!

The specs for the recently built culvert between the sites and the floor of Hangar 2 were significantly greater than 6 inches of poured concrete!

When was that used??? 😮

During the war?

Couple of years back someone pulled a fully fuelled Gulfstream into a hangar at VNY & it went thru the floor up to the wheel spindles……

Oops..

…. I reckon gone the days when 6in of non-reinforced poured concrete was sufficient….

When was that used??? 😮

Concrete hardstandings

Steel mesh fabric reinforcement will still be required (anti-shrinkage)………

There is a CAA CAP document which lists the uk specifications. Use the search function on the CAA website unless someone has it to hand….

edit: I think its in CAP168 – airfield licensing