Demolition methods can range from one devastating blast to careful, piece-by-piece dismantling and challenges contractor faces while demolition

1. DEMOLITION OF BUILDING
& BLASTING EQUIPMENT
CHETAN KARWA

2. INTRODUCTION
 We know every structure is designed for
a life period
 The existence of the structure after the
service life period is very dangerous to
its occupants and surrounding buildings
 The building act usually contains
provisions that enable local authorities
to control demolition works for the
protection of public safety and to ensure
adjoining premises and the site are
made good on completion of the
demolition

3. DEMOLITION

4. STEPS BEFORE
DEMOLITION
• The different steps before the
execution of demolition process are:
1. Surveying
2. Removal of hazardous materials
3. Preparation of plan
4. Stability report
5. Safety measures

5. PREPARATION
OF PLAN
A plan showing:
• all floors of the building to be demolished, with
adequate sectiona
• The structural arrangement and construction of all
unconventional structural elements
• The procedure for the demolition of the building
• Route of movement of powered mechanical plants
and equipment
• All precautionary measures for the protection of the
public
• Descriptive notes on the proposed methods for
handling and
• disposal of debris proposed shoring and precautionary
measures for all affected adjacent buildings, slopes,
retaining structures and services teach stage of the
demolition works

6. STABILITY REPORT
• The Stability Report shall include the following
parts:
• A report on the stability of the building to
bedemolished during all stages of demolition
• A report on the stability of the building with
supporting calculations to demonstrate that the
use of the plants and equipment will not rende
adequate the margin of safety of, or cause damage
to any building, structure, street, land an servicess
• structural calculations for all temporary supports
and bracings
• A report on the stability of neighbouring
buildings,adjoining properties.

7. SAFETY
MEASURES
• Training and Communication
• Equipment Maintenance
• Electrical Safety
• Fire
• Occupational Health
• Emergency Exit Requirements in
Demolition
• Sites
• Vibration
• Environmental Precautions

8. Advantages and
Disadvantages of
Ball and Crane
method
• Advantages
1)To demolish roofs and other horizontal spans
2)The wrecking balls are still used when demolition
may not be possible due to local environmental issues
or asbestos/lead building content
• Disadvantages
1)It demands a great deal of skill from the crane
operator
2) The height of a building that can be demolished is
limited by crane size and working room; however,
buildings as high as 20 stories have been demolished
3) The breakup process can cause considerable dust,
vibration and noise which may be objectionable

9. Advantages and
Disadvantages of
Dismantling
method
• Advantages
1)Reducing disposal costs where waste collection,
hauling or disposal is supported by the tax base
2)Building components that are dismantled will need
to be stored in a secure, dry location. This will
protect them from water damage and theft
• Disadvantages
1)The amount of time and cost of labor are the main
drawbacks
2)Harvesting materials from a structure can take
weeks, whereas demolition may be completed in
roughly a day
3)Toxic waste such as asbestos sheets and lead paint
have no resale value so they are discarded

10. Advantages and
Disadvantages of
Pressure Bursting
method
• Advantages
1)The hydraulic breakers have tremendous
power output also means they are the most
power efficient, getting the most work out of the
available energy
2)A properly used and maintained hydraulic
machine can last for a long time
3)Pneumatic breakers are simpler tools with
fewer moving parts, requiring less maintenance
• Disadvantages
1)They require power, fuel or battery for their
work.
2)They tend to be the most expensive types.
3) They require an external power source.

11. WRECKING BALLS
• In case of buildings have greater heights (5 to 6
story) normal excavators and bulldozers are no
sufficient. In such cases crane with wrecking ball
are used to perform the demolition activity
• The wrecking balls are steel balls hanging from
steel rope which is attached to the crane
• This method is more effective only for high rise
masonry structures because of the uncontrolled
backward movement of steel ball after th impact
on the wall surface
• Now this method not commonly used because
of this uncontrolled behavior of wrecking balls

13. HIGH REACH
EXCAVATORS
• High reach demolition excavators are more often
used for tall buildings where explosive demolition
is not appropriate or not possible
• These excavators are used to demolish up to
height of 300 feet. These excavators with some
attachments are also provided for some specific
purposes
• Hydraulic hammers are often used for concrete
structures and concrete processing attachments
are used to crush concrete to a manageable
size,and to removing reinforcing steel

14. PROCESS OF
BLASTING
• The blast holes are made andcleaned by using
the tools
• The charge of explosive placedat the bottom
• Remaining portion is filled withclay and tamped
• Fuse is inserted, kept projecting15-20 cm above
the rocksurface
• Thereafter free end of fuse is fired by detonator

15. CONCLUSION
• Type of demolition method depends
upon various factors such as site
condition, type of structures, age of
building,height of building and
economy
• Anyway controlled demolition of
building is necessary to ensure safety
• Explosive demolition is the
preferred method for safely and
efficiently demolishing the larger
structures