Asphalt is a resilent material; concrete is not. I suspect few playground courts are concrete. The vast majority are asphalt.

Here's a book about basketball, Asphalt Gods, that says it all:

Highlighting a little-known piece of New York history, Mallozzi, a sports editor at the New York Times, documents the Harlem basketball institution called the Rucker Tournament. Begun in the 1950s by young, Harlem-born Holcombe Rucker, the tournaments included some of basketball's great games throughout the decades. Here, such pros as Julius Erving, Wilt Chamberlain and, more recently, Kobe Bryant pounded the asphalt with local unknowns. Mallozzi, who grew up and played basketball nearby in the 1970s and 80s, has covered the tournament since 1986: "nowhere else could I find the kind of basketball that was being played at Rucker Park, where legends, nicknames, and great rivalries are born every summer." While he celebrates the tournament's past glory (Rucker died of cancer in 1965 at the age of 38), he doesn't shy away from its sometimes controversial moments (many people think it's become simply a hip-hop show and shoe ad, where the game is hardly taken seriously). Mallozzi lends an even hand to this fast-paced tale.