In response to Jeff's comment...
CONCRETE: Virtually maintenance free, just hose it down or sweep it off when it becomes dirty. Can handle heavy loads (i.e. trucks) with no trouble at all. Can be constructed with attractive tints and patterns. Can be constructed with a slip-resistant surface. Can be constructed almost perfectly flat.
ASPHALT: Requires periodic application of sealants, but not a lot of maintenance. Tends to get excessively hot under summer sun. Can loosen or get sticky when excessively hot. Will sink and crack under extremely heavy loads. Any color you want so long as you want black. Surface almost perfectly flat until it cracks. Surface somewhat slip resistant, but can be slippery when wet. Shorter service life than concrete, but also much cheaper than concrete.
WOOD: Requires constant attention to fasteners and decking condition. Requires regular application of weatherproofing sealants. Requires periodic replacement of broken, warped, rotten, or damaged boards. Cannot easily handle extremely heavy loads. Cannot be laid in a smooth surface...deck may include trip hazards. Not slip resistant when wet. More expensive than concrete.
PLASTIC BOARDS:
Also requires attention to decking condition and fasteners. Cannot easily handle heavy loads. Deck may include trip hazards, but manufactured decking is more uniform than lumber. Can be given an anti-skid surface, but generally slippery when wet. Depending on manufacturer, generally about the same as, slightly more, or slightly less than wood planking. Molded in color does not usually look like wood.
That's all right off the top of my head, and I am sure there are advantages and disadvantages of each that I missed. But it doesn't take a rocket scientist to see that concrete is really the most logical choice from a maintenance and durability standpoint.
--Dave Althoff, Jr.