# Bar Bending Schedule Calculation - PDF

Document Sample

```					Exercise No. 3                                                                               Estimating And Costing

Exercise No. 3
1.0    Title:
TAKING OUT QUANTITIES FOR SMALL R.C.C. STRUCTURE SUCH AS HALL.

2.0    Prior Concept :
Units of measurements of various items of work.

3.0    New Concepts :
3.1       Propositions
Proposition 1 : Length of straight Bar with Hooks at both ends

S = End cover

L = Clear span

FIGURE 3.1                      b = End Bearing
Fig. of Beam

Length of straight Bar (main)          = Clear span + 2X (End Bearing) - 2 X End cover+2 X 9d
= ( L +2 X b ) -2 X s + 2 X 9d, where d is diameter of bar.
Proposition 2 = Length of Bent up Bar with hooks at both ends

FIGURE 3.2
Additional length due to inclination = 1.414x - x = 0.414x
.'. x = center to center distance between top portion & bottom portion of bars.
= Total depth of beam - (Top & Bottom cover) - half dia. of main bar at top - half dia. of main
bar at bottom
Length of bent up bar     = length of straight Bar + 2 (Additional length due to inclination)
= ( L +2 X b ) -2 X s + 2 X 9d +2X 0.414x
Proposition 3 :- Length of stirrups (Mild Steel)
Depth of stirrups = Total Depth - Top cover - Bottom Cover
Width stirrups     = Total width - 2 (Side cover)
Length of stirrups = 2 (Depth of stirrups) +
2 (Width of stirrups) +
Length of hook (15 cm / 24 x Φ)
where Φ - diameter of bar
Proposition 4 :- Number of stirrups
Total length - 2 x end cover
No. of stirrups = ---------------------------------------- + 1
Spacing

18 ♦                                                      MAHARASHTRA STATE BOARD OF TECHNICAL EDUCATION
Estimating And Costing                                                                               Exercise No. 3

Proposition 5 :- Weight of bar
Weight of bar per running meter
= C/s Area of bar x density of bar
= (πΦ2) x 7850 kg/m3
4
= Φ2 Kg/m where Φ is in 'mm'
162
Proposition 6 :- Quantity of Bar
Quantity of Reinforcement = No. of Bars x Length of Bar x Wt of bar in Kg/m
Note : Standard length of one Reinforcement bar = 12m
Proposition 7 :- Lap length
Lap length in column = 45 Φ
Lap length in beam and slab = 69 Φ
Φ is in 'mm'
Proposition 8 :- Quantity of Form work

1)      For RCC Beam
Quantity = (b+2d) x l      Sq. meter

2)      For RCC Rectangular Column
Quantity = 2 (l+b) x h Sq. meter

3)      For RCC Circular Column
Quantity = π x d x h Sq. meter

3.2     General concept of structure :-

4.0    Learning Objectives:
4.1     Intellectual Skills:
(i)       To understand the procedure of calculation of quantities of steel, concrete & form
work.
4.2     Motor Skills:
(i)       To develop ability to calculate the quantities of steel, concrete , form work and entering
them in a measurement sheet.

MAHARASHTRA STATE BOARD OF TECHNICAL EDUCATION                                                               ♦ 19
Exercise No. 3                                                                         Estimating And Costing

5.0    Procedure :-
1)        Study the given drawings carefully.
2)        Finalise the items of the work with their units of measurements. Prepare the check list
of the items.
3)        Write brief description of each item of the work on the measurement sheet.
4)        Calculate length, width & depth of different components for calculation of quantity of
concrete & form work.
5)        Calculate the quantity of form work for beam, column. (One sample).
6)        Enter the length, width/breath & depth/height in measurement sheet for concrete & form
work item.
7)        Prepare bar bending schedule.
8)        Calculate the length of bars of different diameter in different components such as slab,
beam, column, footing etc.
9)        Calculate the number of bars of different diameter in different components.
10)       Enter the number, length & weight of bar for different bars in different components in Bar
bending schedule.
11)       Calculate the quantities of items of the work in the measurement sheet.

20 ♦                                                  MAHARASHTRA STATE BOARD OF TECHNICAL EDUCATION
Estimating And Costing                                                      Exercise No. 3

6.0    Observation & Calculation

MEASUREMENT SHEET (Student to write description)

Name of work: …………...………………………………………………………………………………..............

MAHARASHTRA STATE BOARD OF TECHNICAL EDUCATION                                      ♦ 21
Exercise No. 3                                                       Estimating And Costing

MEASUREMENT SHEET (Student to write description)
Name of work: …………...………………………………………………………………………………..............

22 ♦                                    MAHARASHTRA STATE BOARD OF TECHNICAL EDUCATION
Estimating And Costing                                                      Exercise No. 3

MEASUREMENT SHEET (Student to write description)
Name of work: …………...………………………………………………………………………………..............

MAHARASHTRA STATE BOARD OF TECHNICAL EDUCATION                                      ♦ 23
Exercise No. 3                                                       Estimating And Costing

MEASUREMENT SHEET (Student to write description)
Name of work: …………...………………………………………………………………………………..............

24 ♦                                    MAHARASHTRA STATE BOARD OF TECHNICAL EDUCATION
Estimating And Costing                                                      Exercise No. 3

MEASUREMENT SHEET (Student to write description)
Name of work: …………...………………………………………………………………………………..............

MAHARASHTRA STATE BOARD OF TECHNICAL EDUCATION                                      ♦ 25
Exercise No. 3                                         Estimating And Costing

BAR BENDING SCHEDULE

26 ♦                      MAHARASHTRA STATE BOARD OF TECHNICAL EDUCATION
Estimating And Costing                                     Exercise No. 3

BAR BENDING SCHEDULE

Total Quantity =   Quintal

MAHARASHTRA STATE BOARD OF TECHNICAL EDUCATION                     ♦ 27
Exercise No. 3                                                                            Estimating And Costing

7.0    Result :-
The quantities of each items of work are calculated and entered in measurement sheet against
each item with their unit of measurement

8.0    Questions :-
Note: Distribute 3-5 questions to each student for writing the answers in the manual.
1)        A R.C.C. simply supported beam of size 280 mm x 620 mm is reinforced with 4 Nos. of 18
mm diameter main bars. Main bars are placed in one row and two bars are bent up. Two
anchor bars are provided at top and are of 12 mm diameter. 6 mm diameter stirrups are
provided at 150 mm c/c. The span of beam is 5.5 m and end bearing is 25 cm. Calculate the
total quantity of steel reinforcement.
2)        Calculate the quantity of the formwork for the beam in Problem 1.
3)        A R.C.C. simply supported slab of clear size 3.1 m X 6.3 m is reinforced with 12 mm
diameter bars with spacing of 12 cm c/c.. Alternate bars are bent up. Distribution steel is of
6 mm diameter with spacing of 14 cm c/c.Thickness of slab is 10 cm. Bearing of slab is 15
cm. I) Prepare bar bending schedule ii) calculate the quantity of reinforcement.
4)        Calculate the quantity of formwork for the above problem.
5)        Calculate the quantity of concrete for the beam in problem 1.
6)        How Steel quantity is calculated by using percentages?
7)        Compare the quantity of steel reinforcement for column footings calculated by bar bending
schedule and by percentages.
8)        Compare the quantity of steel reinforcement for column calculated by bar bending schedule
and by percentages.
9)        Compare the quantity of steel reinforcement for Beam calculated by bar bending schedule
and by percentages.
10)       Compare the quantity of steel reinforcement for Slab calculated by bar bending schedule
and by percentages.

28 ♦                                                   MAHARASHTRA STATE BOARD OF TECHNICAL EDUCATION
Estimating And Costing                                   Exercise No. 3

MAHARASHTRA STATE BOARD OF TECHNICAL EDUCATION                   ♦ 29

```
DOCUMENT INFO
Shared By:
Categories:
Stats:
 views: 34285 posted: 1/6/2011 language: English pages: 12
Description: Bar Bending Schedule Calculation document sample