Design Principles of Concrete Structures
Lecture 9
Bar Bending Schedule
Bar Bending Schedule
| Serial # | Bar Designation | Number of Bars |
Length of one Bar |
Dia of bar |
Weight of Steel Required |
Shape of Bar |
||||
| #10 | #13 | #15 | #19 | #25 | ||||||
|
1 |
M-1 |
#25 |  |
 |
||||||
|
2 |
S-1 |
#10 |  |
 |
||||||
|
3 |
H-1 |
#15 |  |
 |
||||||
Σ 
Total weight of steel = 1.05Σ , 5% increase, for wastage during cutting and bending
Bar Bending Schedule (contd…)
Bar Bending Schedule (contd…)
90o-Standard Hooks (ACI)
Total Length = L + 18db For R 6db
Table 25.3.2-Minimum inside bend diameters and standard hook geometry for stirrups, ties, and hoops
Table 25.:3.1I – Standard hook geometry for Development
of deformed bars in tension
Bar Bending Schedule (contd…)
Bar Bending Schedule (contd….)
M-1 = 4000 + 2 x 228 – 2 x 40 + 2 x (18 x 20)= 5096
h = 375 – 2 x 40 – 2 x 10 – 2 (15/2) = 260
M-2 = 4000 + 2 x 228 – 2 x 40 + (0.414 x 260) x 2= 5091
H-1 = 4000 + 2 x 228 – 2 x 40= 4376
Bar Bending Schedule (contd….)
Shear stirrups
Number of Bars = 4000 /180 +1 = 24
a = 375 – 2 x 40 – 10 = 285 mm
b = 228– 2 x 40 – 10 =138 mm
Total length of S-1 = 2 (138 + 285 + (4×10 + 75)) = 1076 mm
Bar Bending Schedule
Design of Singly Reinforced Beam by Strength Method
(for flexure only)
Data:
Load, Span (SFD, BMD)
fc’, fy, Es
Architectural depth, if any Required:
Dimensions, b & h
Area of steel
Detailing (bar bending schedule)
Design of Singly Reinforced Beam by Strength Method
Procedure:
-
Select reasonable steel ratio between ρmin and ρmax. Then find b, h and As.
- Select reasonable values of b, h and then calculate ρ and As.
-
Using Trial Dimensions
-
Calculate loads acting on the beam.
-
Calculate total factored loads and plot SFD and BMD. Determine Vumax and Mumax.
-
Select suitable value of beam width ‘b’. Usually between L/20 to L/15. preferably a multiple of 75mm or 114 mm.
Round to upper 75 mm
-
- Decide the final depth.
Preferably “h” should be multiple of 75mm. Recalculate “d” for the new value of “h”
-
Calculate “ρ” and “As”.
Four methods
-
Check As ≥ As min.
As min = ρmin bd (ρmin = 1.4/fy to fc’ ≤ 30 MPa)
7.Carry out detailing
8.Prepare detailed sketches/drawings.
9.Prepare bar bending schedule.
Concluded
