This document discusses demolition work of existing buildings. It defines demolition as tearing down or falling down of a building with equipment or explosives. It outlines the necessity of demolition when structures are old, need structural changes, or have failed. The document describes safety aspects of demolition like falls, falling materials, and electrocutions. It recommends disconnecting utilities, barricading openings, and removing debris constantly. Demolition methods are discussed for different building types like masonry, steel, concrete, and post-tensioned units. The sequence of demolition is described as the reverse of construction with non-structural elements removed first.

1. Eng. Kishor K. Ade
DEMOLITION WORK OF EXISTING BUILDING

2. Eng. Kishor K. Ade
Topic
What is demolition?
Necessity of demolition
Safety Aspects
Causes of Accidents
Precautions during demolitions
Sequence of demolition
Methods of types of demolition
Methods used in demolition of various types of
buildings
Bricks and masonry buildings

3. Eng. Kishor K. Ade
Topic
Methods used in demolition of various types of buildings
Masonry and brick arches
Steel frames and component
Bridges and gantries of steel construction
Reinforced Cast In-Situ Structures
Suspended Reinforced concrete slabs
Reinforced Concrete Beam
Reinforced concrete columns
Reinforced Concrete walls
Structure made of post-tensioned units

4. Eng. Kishor K. Ade
WHAT IS DEMOLITION?
Demolition of a building means tearing down or falling down
of a building with the help of equipments or explosives.
This lecture deals with how a demolition work is to be
Performed safely and also elaborates different steps involved
before and during the execution of a demolition process.
The various steps involved before the demolition process
includes surveying, removal of hazardous materials,
Preparation of demolition plan, stability report and precautionary
safety measures to be taken. The main equipment used for
These demolition activities are sledge hammer, excavators,
bulldozers, wrecking balls etc. And main explosive
Used are dynamites and RDX. When explosive are used for the
demolition, it is known as implosion.

5. Eng. Kishor K. Ade
NECESSITY OF DEMOLITION
When the building is too old and cannot be put
to further use
Structural changes
Development of the city
Structural failure of the building
Expansions

6. Eng. Kishor K. Ade
STEPS BEFORE DEMOLATION
Surveying
Removal of hazardous material
Preparation of plan
Stability report
Safety measures

7. Eng. Kishor K. Ade
Safety Aspects
Causes of Accidents
Falls of persons on site
Falling materials
Unintentional collapse
Lifting operations
Electric shocks
Fire

8. Eng. Kishor K. Ade
PRECAUTIONS DURING DEMOLITIONS
People involved in the demolition work may not know the structural
part of the building, so guidance in this aspect must be competent
and continuous.
Plans of the structure must be checked before demolition.
First step is to ensure all the existing services like electricity have
been disconnected.
Windows and door opennings must be boared up.
Internal entrances to lift shafts etc must be barricaded.
Balconies and cantilevers must be taken down first. Stair must be
kept free from debris.
Must not stand on the brickwork which is being demolished.

9. Eng. Kishor K. Ade
SEQUENCE OF DEMOLITION
1.First task in the site is that the services to the buildings
have been disconnected.
2.Demolition happens in the reverse order of construction.
3.The preliminary stripping out process such as roof
coverings, fittings pipe work and generally all
non structural part of the building.
4.All rubble and debris must be lowered to ground
constantly.

10. Eng. Kishor K. Ade
METHODOLOGY

11. Eng. Kishor K. Ade
Methods used in demolition of various types of buildings
Bricks and masonry buildings
Mortar breaks away very easily from the bricks,
where bricks often remain in one piece and thus are
easily salvaged.
Demolition by reverse order of construction.
Building must be demolished by hand to wall plate
level.
Careful removal of members in tension must
be done.
After careful demolition the site should be 'back
bladed' to ensure there are no pieces of bricks or
concrete is left on the site

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