Formwork and falsework
Definition
Material
Good form work
Failure of formwork
Timber
Plastic
Steel
Disadvantage
Advantage
Tightness
Simple Election and stripping process
Strength
Design
Advantage
Disadvantage
Simple design
making it more flexible
Light and easily handled
to faciliate minor change
prevent the loss of grout
Grout
Advantage
Disadvantage
Making it more efficient
Erection process refer to formwork installation process
stripping process refer to formwork dismantling process
Formwork
A mould where fresh concrete can be poured into it and harden to its intended shape
Falsework
Reason
Inadequate design
collection of container that receive concrete mix
Refer to a mixture of water and cement
serves as critical element for binding the concrete
Chosen based on
Cost of material
Availability of skilled worker
Structural form
Speed of construction
Number of reuse
Construction tolerance ,rigidity and accuracy
Finishes required
Easily obtained
Cheapest in first cost
Easily handled and transported
Able to take considerable load
Low life span
Required skilled labour
Timber absorded water which reduced the strength of concrete unless it is sufficiently wetted
Surface is affected by the concrete after serveral reuse
Highest deflection of the 3 material
Striking of formwork
Type of formwork
Modern
Conventional
Unless well finished it gives a rough texture to the concrete
Strongest of material
Most durable
Produced good fair face finish
Easily assembled as it more mechanical
Initial cost is high
Suitable for forming right angles but difficult to form curve
High thermal expansion and contraction
Durable
Easily repaired when damaged
Forming circular & irregular shape
Cannot be used in high temperature extreme
Production cost is high unless produced in great quantities
Impact
Result in injuries and death
Recovery cost and downtime due to such failure will cause adverse impact to the project schedule
prevent such failure
Supervisor is required
to supervise erection,alteration or dismantling and inspection of form work
To attend mandatory formwork safety course for supervisor
Improper stripping and shore removal
Inadequate bracing
Vibration loads
Unstable soil under mudsills
Shoring not plumb level
Inadequate control during concrete placement
Lack of attention to formwork details
modular in shape
For efficiency and speed
Type of modern formwork
Table form/Flying formwork
System formwork
Slip formwork
Tunnel formwork
Foundation form work
Column formwork
Slab and beam formwork
Wall formwork
Staircase formwork
Serves as a mould for wet concrete
enabling it to harden to the desire size and shape of the finished reinforced concrete structure or component
Supporting system for formwork mould of a structure which is cast above ground level
System which locate and retain the formwork
in the desired position in a stable and safe manner
process of removing the formwork from the surface of the hardened concrete
Once the concrete has achieved the initial recommended strength to support both the dead and live load
Soffit
underside of slab ,beam and similar structural component
click to edit
usually place in a longer period of time and is removed last in the form of slab and beam
Miniumn period to removed
vertical formwork
1 day
Soffit of slab and beam less than 500mm thick
3 day
Soffit of slab less than 500 mm thick
7 days
Soffit of slabs more than or equal to 500mm thick
depend on concrete material
soffit of beam
3days
Soffit of cantilever beam and slab
7 days
props to slab and beams
14 days
props to cantilever beam and slab
21 days