Field note / reinforcement quantity
Start with the clear width.
If a strip has overall width W and nominal cover c at both edges, the available bar-to-bar width is Wclear = W - 2c. This is the width over which the bar centres are distributed in this simple screen.
Use the requested spacing as a maximum.
For maximum spacing s, the count is n = ceil(Wclear / s) + 1. Adding one accounts for a bar at each end of the clear width. The resulting actual spacing is recalculated from the count, so it will be equal to or smaller than the requested maximum.
Separate geometry from procurement.
Total order length is the bar count multiplied by cut length, with the entered lap or cutting allowance applied. Approximate mass is then total length multiplied by the nominal relationship d2 / 162 kilograms per metre.
What the screen cannot decide
- Development length, lap length, hooks, bends, couplers, bar shape codes, and wastage from cutting stock.
- Layer arrangement, chairs, spacer requirements, congestion, crack control, durability, and construction tolerances.
- Whether a code, drawing, or project specification limits the spacing more tightly than the entered value.