Jersey runway resurfacing

[Wilton Shagpile]

The NOTAMs for JER state that the runway surface is POROUS FRICTION COARSE as a result of the rehabilitation works.

I have never come across this before...does anybody know what this means in terms on braking preformance relative to grooved ashphalt surfaces...especially when wet?

Thanks.

[Bullethead]

I found this on the 'net' which seems to explain it. It is an alternative to grooving and some authorities consider a PFC coated wet runway to be equivalent to bare and dry.

8-3 . Porous friction surface course . Porous friction surface course
consists of an open graded bituminous concrete containing a large
proportion of one-sized coarse aggregate . The large void content
permits water to drain through the layer laterally out to the
shoulders . Porous friction courses are also described as "open graded
mix," "plant mix seal," and'"popcorn mix ." In addition to improving
skid resistance and preventing hydroplaning, porous friction courses
provide the following additional advantages :
- Improved visibility of pavement marking .
- Reduced tire splash and spray .

Some disadvantages include :
- Susceptibility to fuel spills .
- Susceptibility to clogging by mud, blow sand, and rubber .

Regards,
BH.

[OverRun]

T’is a valid question about the difference between porous friction course (aka open grade, popcorn etc) and grooving. The short answer is that, for performance engineers and pilots alike, there is no difference at all.

The long answer would run to hundreds of pages, and would come to exactly the same endpoint as the short answer.

For those students of human frailties, you’ll be amused that the choice of friction treatment is little more than the “flavour of the month”. Today, for example, Australia is in the grip of the ‘grooving school’. The British seem to be slightly more in favour of grooving – perhaps it’s all those regimented ‘stripes’ that attract their attention. The South Africans don’t trust grooving at all – since it must have been a remnant of a previous dispensation. The Americans like both; varying between grooving (for the groovy) and porous (for popcorn lovers). The Germans like SMA, because they invented it. The French like anything that is spelt in French.

For myself, I have given up on making a choice between the two. Whatever the airport wants is fine. They both work as well as each other, and there is no point trying to persuade a dedicated stripes man that he should choose something full of holes, and vice versa. All I want to see is that the airport has one of the friction treatments.

[demomonkey]

containing a large proportion of one-sized coarse aggregate

So someone has sprinkled gravel all over the runway? I heard they also bought a couple of new storm lanterns to bring their lighting up to the required standard also. Cool!

:O