There is a product (Mig or Ak) that is a spreadable tarmac.
Alternately a cold-pressed "crescent" board will have about the right texture with a good coat of craft paint.
Asphault (often called Tarmac, a contraction of tar MacAdam) is a gravel aggregate coated in heated bithumenous tar which adheres the material together when it cools. It's a black to brown-black color which can fade to a dark gray.
Tar MacAdam is a process where a compressed gravel subgrade is coarted in a hot liquid tar. While still hot and wet a wear layer of fine gravel is evenly spread over the road surface. Final color depends on the color of the wear layer gravel.
How the tradition of referring to aviation aprons as tarmac got started is not entirely clear. Tarmac, proper would be a horrible FOD pavement. Asphault spreads easily and is very forgiving pavement, but only up to certain traffic loads. Which is why most modern air fields use concrete for being more economical for carrying large loads--6" of 6000 psi concrete is far cheaper than 12" of layered asphault. Asphault installed south of about 33ºN has an issue with losing some of its compression strength, too.