Stone, crushed

M (276, 276) Rock drilling, stone crushing, stone dust — job/task history OR 2.2 (1.2, 3.9) Stolt39... 

Loose stone Crushed stone chips (top) in a variety of colors and textures—byproducts of the quarrying industry—make an acceptable alternative to quarried gravel or dredged gravel (bottom). A "scree garden" made with such chips or crushed brick waste is an effective way to display alpine plants, avoiding the environmental concerns caused by garden rock features (seep.134). 

Ballasted. A ballasted roof assembly consists of a membrane or membrane and substrate material (insulation, slip sheet, etc) loosely laid over a deck with the assembly held in place using ballast. A minimum ballast weight of 48.9 kg/m2 or 10 pounds per square foot (PSF) is used. The ballast can consist of smooth rounded stone, crushed stone (a separator sheet must be used between the cmshed stone and the membrane), or pavers (both standard and lightweight). Both stone and pavers come in a wide variety of colors. The membrane is affixed to the building only at the deck perimeter (roof edge) and at various penetrations. Wall and penetration flashings are typically fully adhered and sealed to prevent water entry into the roof assembly. The maximum slope a ballasted system should be installed over is 16.7 cm/m. 

Width of belt Light or free-flowing materials, grains dry sand, etc. Moderately free-flowing sand, gravel, fine stone, etc. Lump coal, coarse stone, crushed ore Heavy sharp lumpy materials, heavy ores, lump coke ... 

The aggregates should consist of crushed stone, crushed gravel or crushed slag (air cooled, blast furnaced) with or without natural sand or other inert, finely divided mineral aggregate, provided they meet the requirements summarised in Table 5.12. 

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