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Table 2 Concrete mixes (by volume) Concrete Strength
Cement (part)
Water (not more than)
Sand (parts)
Coarse Aggregate
2,200 psi (15 MPa)
1
20 L (4.4 imp. gal.) per 40 kg (88 lb.) bag of cement
2
4 parts up to 50 mm (2 in.) in size
1
20 L (4.4 imp. gal.) per 40 kg(88 lb.) bag of cement
-
6 parts pit run gravel
1
18 L (4.0 imp. gal.) per 40 kg(88 lb.) bag of cement
13⁄4
3 parts up to 40 mm (11⁄2 in.) in size
1
18 L (4.0 imp. gal.) per 40 kg (88 lb.) bag of cement
-
43⁄4 parts pit run gravel
3,000 psi (20 MPa)
Note to Table 2 1. For higher strength concretes, use commercial suppliers to ensure strength and air entrainement requirements are met
Table 3 Minimum depths of foundations Foundations containing heated basement or crawl space
Foundations containing no heated space
Good soil drainage to at least the depth of frost penetration
Poor soil drainage
Good soil drainage to at least the depth of frost penetration
Poor soil drainage
Clay or soils not clearly defined
1.2 m (4 ft.)
1.2 m (4 ft.)
1.2 m (4 ft.) but not less than the depth of frost penetration
1.2 m (4 ft.) but not less than the depth of frost penetration
Silt
No limit
No limit
Below the depth of frost penetration
Below the depth of frost penetration
Coarse grained soils
No limit
No limit
No limit
Below the depth of frost penetration
Rock
No limit
No limit
No limit
No limit
Type of Soil