One thing I have noticed in recent years is that almost all of the new runways being built in the US seem to be Concrete runways. This includes the rebuilt 7R-25L in LAS, the rebuilt 13R-31L at JFK, the new runways that have been built at CLT, CVG, and ORD to name a few. However I also notice BOS continues to use Asphalt to rebuild runways at BOS, even going as far as touting a warm mix asphalt that they use which is more enviornmentally friendly. My thing is, Concrete seems to be better for the environment than Asphalt from what I see. That aside, I notice that all the surface movement areas at BOS are asphalt and there is a lot of cracking that keeps having to be sealed, which I have not seen at airports with Concrete.
So my question is this, why is BOS using Asphalt instead of Concrete, when everyone else seems to be using Concrete, and is one really better than the other? Concrete seems better to me, but BOS still won't use it.