concrete formwork

Question 1

what is the definition of formwork?

Answer 1

the total system of
support for freshly placed concrete,
including the mould or sheathing,
supporting members, hardware, and
necessary bracing, but excluding the
falsework

Question 2

What is the definition of falsework?

Answer 2

any temporary
structure used to support a
permanent structure while it is not
self supporting.

Question 3

what is the cost breakdown for a 24cm thick concrete wall?

Answer 3

Question 4

what are the 2 main costs of formwork?

Answer 4

• Labor costs for formwork construction
  – Productivity and number of uses

Question 5

name the basic components of formwork along with brief sketch

Answer 5

Question 6

what parameters influence fresh concrete pressure?

Answer 6

• Setting characteristics
  – Rate of rise
  – Consistency
  – Pouring height
  – Method of pouring and compaction

Question 7

what are the 3 different concrete pressure loads?

Answer 7

Question 8

what are the two types of formwork?

Answer 8

conventional and system formwork

Question 9

what is conventional formwork?

Answer 9

Mainly handcrafted on site. Timber is basically used for the surface
and the scaffolding of the formwork. Metal parts function as supporters and fasteners.

Question 10

what is system formwork?

Answer 10

less craftsmanship is necessary. The formwork gets constructed by using different types of prefabricated formwork components.

Question 11

true or false, its common to see both conventional and system formwork at the same time?

Answer 11

true

Question 12

what is the standard panel size for conventional formwork?

Answer 12

0.5 x 1.5m

Question 13

what is two-faced formwork ties/anchors

Answer 13

To absorb the loads from the fresh concrete pressure,
tension ties/anchors are used for wall formwork.
- Tie: threaded ties
- Plastic or fiber-cement ducts; special design if water
tightness is required

Question 14

what are typical formwork operations during the construction process?

Answer 14

• Slab – and beam formwork
• Wall formwork
• Column formwork

Question 15

what is beam formwork?

Answer 15

The formwork for beams can be build
on top of slab formwork. Another
possibility is to use a trough shaped
rail system.

Question 16

what are the the 3 common wall formwork types?

Answer 16

• The very flexible beam formwork –
  mainly handcrafted.
• Panel formwork – less
  craftsmanship necessary because of
  the use of prefabricated formwork
  elements.
• Circular formwork for
  curved/rounded walls.

Question 17

what is tunnel formwork?

Answer 17

• Tunnel forms are designed to cast walls and top slab at the
  same time. They are ideally used for buildings with similar
  sections.
• Any change of the formwork system is expensive and should be avoided.
• The formwork can be moved by cranes or by itself (gantry)
  while using an undercarriage.

Question 18

when would the use of climbing formwork be used?

Answer 18

• For constructing high rise buildings or building components, it might be necessary to use special formwork and building procedures. For those occasions it is ordinary to use climbing forms. It is important to
  distinguish between those forms that climb independently, and those that don’t.
• While climbing formwork relies on “young” concrete to support it, it is very important to plan every step carefully. It is mandatory to
  involve both structural design and concrete experts early on during job preparation.

Question 19

what is self climbing formwork?

Answer 19

• Climbs independently from casting segment to casting segment by using hydraulic jacks, so the crane can be used for other operations.
• The working platforms are able to bear both, the load of material and working equipment. The work can go on in almost every
  weather condition

Question 20

what is slip or sliding formwork?

Answer 20

• Vertical progress: The formwork system is sliding continuously upwards. It is mounted onto climbing bolts and a yoke system. The
  lifting device runs hydraulically or pneumatically. The finishing platforms completes the formwork system.

Question 21

what is horizontal sliding formwork?

Answer 21

Horizontal progress : The sliding formwork follows a given line. This
procedure can exemplarily be used for curbs, gutters or concrete barriers.

Question 22

list 5 items that you would need to consider before approving or disapproving the use of a concrete pump instead of bucket

Answer 22

• aggregate size
• workability
• cement content
• field practices
• pumping