Mar 2, 2020

Session 7 : RCC Work (Footing/Raft Foundation) (Free Online Quantity Survey and Estimation Course)


1 Name of Work & Description

RCC (Reinforced Cement Concrete) Footing and Raft Foundation: This is a sub-base structure of any building, which is called Foundation. All Load of The building is diverting to rock through the footing. Therefore footing is the Main structure of any building. Footing Contains Reinforcement is Concrete as per given design by the structural consultant.  

Types of Footing Concrete
1 Step Footing
2 Isolated Footing
3 Trapezoidal Footing
4 Box Footing
5 Combined Footing
6 Shoe Footing
7 Raft Foundation  

2 IS Code No.

Plain and Reinforced Cement Concrete IS Code: IS456:2000
Code of Practice for laying in-situ Cement Concrete Flooring: IS2571:1970
Methods of tests for aggregate for concrete: IS: 2386
Compressive strength test for cement mortar cubes: IS: 2250
Methods of sampling and analysis of concrete: IS: 1199
Specifications for fine & coarse aggregate from natural sources for concrete: IS: 383 

3 The Drawing Needs to Read.

Following drawing need to study before starting the Foundation of any structure.
1 Footing Layout Drawing
2 The layout of Building/Structure
3 Foundation/Footing Section
4 Footing Foundation layout and Schedule.
5 Plinth Level Drawing6 Raft Layout
7 Raft Section8 Raft and Retaining Wall Section 

4 Location of Work

The footing is the Basic structure of any building which is mandatory for each and every structure. The footing is generally located below the ground.
1 Below Plinth Level
2 Below plinth beam
3 Raft at Basement of Building
4 Raft for Water Tank
5 Raft for Industrial Machine Foundation 

5 Standard Procedure of Work (Step by Step)

Following procedures before start Foundation Work/ Footing Work.
1 Depth of Footing/ Raft Foundation
2 Size of Footing/ Raft Foundation
3 Marking of Footing/ Raft Foundation
4 Steel Reinforcement of the Desired diameter as per drawing
5 Shuttering for a raft of footing with proper support.
6 Concreting as per the given mix design as per the standard procedure. 

6 Checkpoints

RCC Footing/Raft Foundation Checkpoints is as follows
1 Position of Footing/ Raft Foundation
2 Depth of Footing/Raft Foundation
3 Shuttering Size as per drawing
4 Steel Reinforcement is as per drawing
5 Grade of Concrete6 Quality of Concrete
7 Curing  

7 Equipment and Machinery

Cast in situ Footing/ Raft Concreting required following Material
1 0.5 Bag/1 Bag Manual or semi-automatic Concrete Mixer, Batching Plant, Ready Mix Concrete.
2 Weight batcher
3  Wheel Borrow
4 Shovel & Ghamela
5 Thapi,
6  Line Dori
7 Measurement Tape
7 Auto level and staff.
8 Concrete Pump
9 Steel Cutting Machine
10 Ply Cutting Machine
11 Hammer
12 Steel Bending Machine
13 Nails
14 Ply/ Plate/ Advanced Shuttering Material
15 Props/ Wooden Props 

8 Measurements and Quantity Survey

Footing/ Raft Foundation Concrete is measuring in 2 units as Cubic Meter and Cubic Feet.
The following are the procedures to take and write the measurements of RCC. 
If the Size of Footing is 1500 mm X 1500 mm and thickness is given 600 mm, Then we can calculate two types of measurements.
1 Cubic Meter: 
Size of Footing: 1500 mm X 1500 mm
Depth of Footing: 600 mm
The volume of Footing: 1.350 Cum
Concrete Quantity in Cum: 1.350 Cum
Concrete Quantity in Cubic Feet: 1.350 x 35.28: 47.628 Cubic Feet 

Quantity Calculation as per Footing Type

1 Step Footing
Concrete Quantity
1 volume of Step 1: L X B X D1
2 Volume of Step 2: L X B X D2
Total Volume of Step Footing: Volume of Step 1 + Volume of Step 2

Shuttering Quantity
1 Shuttering Quantity of Step 1 : (L+B+L+B) X D1
Shuttering Quantity of Step 1 : (L+B+L+B) X D2
Total Shuttering Quantity of Step Footing: Shuttering Quantity od Step 1 + Shuttering Quantity of Step 2

2 Isolated Footing
Concrete Quantity
Volume of Footing: L X B X D

Shuttering Quantity
Shuttering Quantity : (L+B+L+B) X D

3 Trapezoidal Footing
Concrete Quantity
Volume of Footing: H/3 x (A1 + A2 + (√A1 X A2))

Shuttering Quantity

Shuttering Quantity : (L+B+L+B) X Base of Footing

4 Box Footing
Concrete Quantity
Volume of Footing: L X B X D

Shuttering Quantity

Shuttering Quantity : (L+B+L+B) X D

5 Combined Footing
Concrete Quantity
Volume of Footing: Area of Footing X D

Shuttering Quantity

Shuttering Quantity : (L1+B1+L2+B2+L...+B...) X D

6 Shoe Footing
Concrete Quantity
The volume of Footing at Column: L X B X D1
Volumn of Footing at Slope: (Triangular Portion) (1/2 X  Base X Height D2) X Length

Shuttering Quantity

Shuttering Quantity: At Column Side (L+B1+B2) X D1
Shuttering Quantity: At Slope Side (B-B1+B-B2) X D2

7 Raft Foundation  
Concrete Quantity
Volume of Footing: Area of Raft X D

Shuttering Quantity

Shuttering Quantity : (L1+B1+L2+B2+L...+B...) X D

We are providing all structure measurement sheet to all our readers and subscribers in excel format which can be useful for everyone in the future also, If any queries found in this blog or entire this lecture please update us so we can improve us to provide you more information about this course,    

9 Checklists

Checklist for Footing/ Raft Concrete is called Pour Card.
1 Location of Footing Foundation checked
2 Size for Footing checked
3 Center of Footing, Column Position Checking
4 Shuttering and Supports is Checked
5 Steel Reinforcement checked and found as per diameter is given in the schedule
6 Formwork is cleaned and oiled
7 Formwork free from holes and gaps.
8 Formwork size is as per drawing.
9 Formwork is inline-level and plumb. 

10 Quality Tests

Compression test of Cube
Testing of Cement
Testing of Aggregate 

11 On-site Experiences

Footing/Raft Foundation: Foundation is a very important structure of any structure which is should be accurate and should be as per drawing without any mistakes because of all the above structures life s depend on it. 

Thankful to all readers for this huge support so we are thankful to provide you all this knowledge, we can also provide luxurious project information but in India, there are a lot of engineers and a lot of Contractors is working of the middle-class project if we will use those type of advanced technologies in such budget project cost of the project will hamper therefore we are providing basic point which needs to clear at the time of quantity survey and estimate sessions. After all the mentioned section we are going to start rate analysis of each item and after that, we will proceed for an estimate step by step.  

CBEC India

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