Hi,
How does SFA determine the mass of reinforcement steel? Where can I find the steel density value/s that SFA uses?
Please let me know the type of footing and the design code in which this MTO is generated? Also please attach the SFA file
Assuming you have used the ACI metric code, here is my answer.
Weight of steel= Cross section area of single bar*total length*density of steel
An example calculation for the first row values in your screenshot will be
Weight in kg=( pi*(9.525/1000)^2/4 )* 145.60*7850=81.442 kg
SFA calculates bar number and number of bars during reinforcement calculation. For example #8 @ 250 mm c/c means #8 bar is used at 250 mm c/c spacing.
Now we know the bar area for #8. And we can calculate the number of bars as 1+ roundup( (Total span - 2x cover - bar dia)/ spacing).
Next, we know the dimension of the footing in reverse direction, SO each bar length = Dimension of footing at that direction - 2x cover
So, if we have bar area bar length, we can calculate bar volume. Now density of steel is 7850 kg/***. So, SFA follows the procedure to calculate weight.