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` = "Chairs for Rebar Grid"`
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The Chairs for Rebar Grid function computes the number of support chairs needed to suspend a mat of rebar away from the ground based on the dimensions of the slab and the chair spacing.
INSTRUCTIONS: Choose units and enter the following:
- (L) Slab Length
- (W) Slab Width
- (CS) Chair Spacing (Default: 3 feet)
Chairs for Slab (nC): The calculator returns the number of support chairs needed for the slab.
The Math / Science
To compute the number of point for the chairs in a rectangle grid, where no two adjacent points are more than a specified separation (Chair Spacing), the formula is as follows:
nC = (roundup(L/CS) + 1) * (roundup(W/CS)+1)
where:
- nC = Number of Support Chairs
- L = Length of Slab
- W = Width of Slab
- CS = Chair Spacing
Where you can buy chairs:
Reinforcement Bar (rebar) Functions
- Length of Rebar in Grid: Computes the total length of rebar needed for one or more mats of rebar in a concrete slab based on slab dimensions, rebar spacing, inset from slab edge, number of mats, length of pre-cut rebar sticks, and a rebar lapping factor.
- Weight of Rebar in Grid: Computes the total length and associated weight of rebar needed for one or more mats of rebar in a concrete slab based on slab dimensions, rebar spacing, inset from slab edge, number of mats, length of pre-cut rebar sticks, a rebar lapping factor and the size of rebar.
- Rebar and Concrete in Slab: Computes the total length and weight of rebar and the volume of concrete needed for a slab. The weight and volume calculations take into account the concrete displaced by the rebar. Also provides the total weight of the slab and the cost of rebar.
- Wall (Rebar Concrete and Forms): Computes the length and weight of reinforcement bars (rebar), volume of concrete and the surface area of forms for a wall based on the dimensions of the wall.
- Rebar in an Irregular Shaped Slab: Estimates the total length and weight of reinforcement bars (rebar) needed for an irregular shaped concrete slab.
- NEW Rebar Around Irregular Shaped Area: Estimates the total length and weight of rebar and concrete needed for a slab with an irregular shaped void (e.g. swimming pool) inside the slab.
- Rebar in a Circular Slab: Estimates the total length and weight of reinforcement bars (rebar) needed for a circular shaped concrete slab.
- Rebar Lapping Length: Computes the length overlap needed at rebar joints based on rebar size and a lapping factor.
- Rebar Cost Estimate: Computes the total cost of rebar based on the length being purchased, length of the individual pieces being bought and unit price of one piece of rebar.
- Weight of Rebar: Computes the total weight of rebar based on the length and size of rebar.
- Concrete Displaced by Rebar: Estimates the net weight added to a slab by adding rebar, and the reduction in concrete cause by adding rebar.
- Weight of Slab with Rebar: Estimates the weight of a rectangular slab with rebar base on the slab dimensions, rebar size and space and the know density of both concrete and rebar (steel). It also includes the individual weight of the components and the volume of concrete accounting for that displaced by rebar.
- Rebar Price per Pound: Computes the price per pound of rebar based on the unit cost of a rebar stick, its length and size (2-20).
- NEW Chairs for Rebar Grid: Computes the number of chairs needed to suspend a rebar grid.
See also the Calculadora de Barras de Refuerzo Collection for the Spanish version of the above.
