graded gravel

listen to the pronunciation of graded gravel
English - Turkish
(Mimarlık) Tasnif edilmiş çakıl, elenmiş çakıl, derecelendirilmiş çakıl

The typical sand bed has tile underdrains by 12 inches of graded gravel.

poorly graded gravel
kötü derecelenmiş çakıl