Macadam
Videos
Macadam is a type of road construction pioneered by Scottish engineer John Loudon McAdam c. 1820, in which crushed stone is placed in shallow, convex layers and compacted thoroughly. A binding layer o
An illustration of the first macadamized road in the United States between Boonsboro and Hagerstown in Maryland in 1823; in the foreground, workers are breaking stones "so as not to exceed 6 ounces [170 g] in weight or to pass a two-inch [5 cm] ring".
Laying Telford paving in Aspinwall, Pennsylvania, in 1908
John Loudon McAdam
A macadam road in Nicolaus, California, c. 1850s
Construction aggregate
Videos
Construction aggregate, or simply aggregate, is a broad category of coarse to medium-grained particulate material used in construction. Traditionally, it includes natural materials such as sand, grave
A limestone quarry in Tennessee, U.S.
10 mm graded crushed basalt rock or aggregate, for use in concrete, called "blue metal" in Australia
20 mm graded aggregate
Class 3 road base