How thick should slab on grade be?
Accordingly, slabs generally cure to a thickness less than poured and often in a non-uniform manner across the area of the slab. Most specifications for retail or commercial concrete slabs specify 4 to 6 inches of thickness.
What is the acceptable tolerance for a concrete slab?
Traditionally allowable tolerances of concrete floor slabs were determined by checking the slab surface with a 10 foot straightedge. Common tolerances were 1/8 inch or 1/4 inch in 10 feet.
What is the minimum allowable thickness for a slab on grade foundation?
ACI-318 limits plain concrete wall thickness to a minimum of 7-1/2 inches; however, the International One- Two-Family Dwelling Code (ICC, 1998) permits nominal 6-inch-thick foundation walls when the height of unbalanced fill is less than a prescribed maximum.
What is the minimum thickness for slabs?
minimum thickness should not be less than 4.75 inches not forgetting factor of safety. Standard concrete floor slab thickness is residential construction is 4 inches, five to six inches is recommended if the concrete will receive occasional heavy load, such as mortar homes or garbage trucks.
What is slab thickness and base tolerances?
For this reason, slab thickness and base tolerances are critical and typically specified in the contract documents. The support system consists of the base, sub-base and sub-grade. The base course, directly beneath the slab, typically consists of crushed rocks and gravels and directly supports the slab.
What percentage of thickness is within a tolerance of a tolerance?
For 2.0 standard deviations, 95 percent of the thicknesses would fall within ±1 in. For 1.5 standard deviations, 87 percent would fall within a tolerance of ±3/4 in. and 68 percent thickness would fall within a ±1/2 in. tolerance for a 1.0 standard deviation.
What is the plus slab thickness tolerance for Aci 117-10?
ACI 117-10 does not specify a plus slab thickness tolerance but does specify a ±3/4 in. top of slab elevation tolerance. The ±3/4 in. fine grade elevation tolerance for the base or the soil immediately below the slab-on-ground corresponds directly with the -3/4 in. slab thickness tolerance for individual samples.
How thick should concrete slabs be for Aci?
Also, to ensure compliance with ACI’s -3/4 in. thickness tolerance, you’ll need better quality control than the contractors that installed the slabs where 30,000 date points were measured. Slabs thicker than the specified thickness will cost more money. Thicker slabs increase concrete costs.