ABSTRACT
DIMENSION STONE This is defined as stone that is used in large blocks, whether rough from a quarry or sawn to size; the rock must therefore have a low fracture density to permit extraction of large blocks. Construction stone may be any locally available rock with UCS 50 MPa. Mostly limestones, sandstones and granites; now largely replaced by concrete. Freestone is any stone that has neither a preferential fracture direction nor any planar weaknesses, so is best used for carved ornamental work. Cladding stone is used in sheets, 10-20 mm thick, as facing panels over concrete. Needs UCS 100 MPa, should be attractive, and must normally take a polish. Dominated by marbles and granites. Armour stone is large, uncut, chunk rock used for erosion defence. Coastal sites exposed to wave action need UCS 150 MPa in large blocks, so granite used; but density 2.8 t/m3 (in dolerite and gneiss) may be specified. Limestone with UCS 100 MPa acceptable for smaller waves on lakes, and for protective riprap of smaller sized blocks on earth dam faces. The high value of cut and polished dimension stones means they may be shipped greater distances, and are therefore widely available. Notable examples include Carrara marble from northern Italy, larvikite from Larvik (Norway), slate from Wales, Rock of Ages granite from Vermont (USA); but much good stone now comes more cheaply from China or India.
