2. OBJECTIVES
● What is precast concrete?
● Reasons to adopt precast concrete
● Methods of attachment of precast concrete
members
● Advantages & Disadvantages Vs site cast
concrete
3. Precast Concrete
Precast concrete is a construction product
produced by casting concrete in a reusable
mould or "form" which is then cured in a
controlled environment , transported to the
construction site and lifted into place.
4. Reasons to adopt precast
concrete
● Precast concrete is
comfortable safe
Versatile healthy
Optimised durable
Ecological fast
Affordable sustainable
5. Methods of attachment of precast
concrete members
This attachment is done in mostly 2 ways.
1 . Weld plates method: The most common
method of attachment of precast members is by
use of steel weld plates. Typically the precast
members have embedded plates that can be
used as welding surfaces.
2 . Rebar and grout method : Used typically with
slabs, reinforcing bars are spliced into slabs and grouted
in place .
6. Advantages
● We can cast desired shape of the concrete prior
to placement in a structure.
● Very rapid speed of construction on site.
● High quality because of the controled conditions
in the plant.
● Entire building can be precast walls,floors and
beams.
● Prestressing is easily done.
● Proper curing is done in the plant.
7. Cont...
● Financially forms used in a precast plant may
reused hundreds of times which allows cost
reduction than site casting.
● Number of advantages by removing the concrete
forming,curing,placing and finishing operations
from the construction environment.
● Low maintenance cost & less deflections.
● Greater control of waste of materials and
workmanship rather than on a construction site.
● Not necessary to provide the joints in precast
construction.
8. Applications
● Storm water drainage , water and sewage pipes,
stairs , tunnels , decorative parts , slabs , beams ,
culverts , bridges , metro projects , under water
infrastructures etc...
9.
10. disadvantages
● If not properly handled , the
precast units may be
damaged during transport.
● It becomes difficult to
produce the satisfactory
joints between the precast
members.
● It is necessary to arrange
the special equipment for
lifting and moving of the
precast members.
11. ● The economy achieved in precast construction is
partially balanced by the amount that spent for
transport and handling of precast members.
● Additional time required for drying out process.
