Gravel ˈ ɡ r 230 v əl is a loose aggregation of rock fragments Gravel is classified by particle size range and includes size classes from granule to bouldersized fragments In the UddenWentworth scale gravel is egorized into granular gravel 2 to 4 mm or 0 079 to 0 157 in and pebble gravel 4 to 64 mm or 0 2 to 2 5 in ISO 14688 grades gravels as fine medium and coarse with
