How to Calculate Steel Quantity for Slab, Footing and Column?

Reading time: 3 minutes

Estimation of steel reinforcement quantity for concrete slab, footing and column, beams etc. is crucial for the cost evaluation for the construction. Design drawings are used as a base for computing rebar quantity in different structural elements. This article presents steel quantity computation process for slabs, columns, and footings.

Calculate Steel Quantity for Slab

1. Obtain slab dimension and reinforcement details from design drawings as shown in Fig.1.
2. Compute number of steel bars.

Main Steel Bars No. of bars= (Slab length(L)/spacing)+1               Equation 1 Shrinkage and Temperature Steel Bars  No. of bars= (Slab length(S)/spacing)+1               Equation 2 In equation 1, center to center spacing of main reinforcement steel bars are used and shrinkage and temperature bar spacing is used in equation 2. 3. Calculate cutting length: Main steel bars  Cutting length= clear span(S)+Ld+inclined length+2x45 degree bend      Equation 3 Shrinkage and Temperature steel bars  Cutting length= clear span(S)+Ld+inclined length+2x45 degree bend      Equation 4 Where: Ld: development length which illustrated in Fig. 2. Inclined length can found from the following expression: Inclined length= 0.45D                                                    Equation 5 D=slab thickness-2*concrete cover-bar diameter               Equation 6 3. Convert that length into kilograms or tons because steel bars are ordered by weight. The same equation used for both main and shrinkage and temperature reinforcement, but corresponding cutting length, number of bars, and bar diameter is used. Main steel bars=No. of bars*cutting length*weight of the bar (