Circular Formwork

Framax Xlife, Alu-Framax Xlife, Frami, Top 50

The quick way to form “in the round” – the Framax and Frami circular forming plates will get your framed formwork around any curve!

Framax Xlife, Alu-Framax, Frami

For convenience and economy existing Framax Xlife and Frami panels and accessories such as struts and pouring platforms can be used.

With the circular forming plates and the panels of the formwork system, ‘circular‘ (i.e. polygonal) structures can be universally, economically and quickly formed.


Perm. concrete pressure 50 kN/m2

Design integration with Framax Panels

By combining the Framax circular forming plates with the Framax Xlife panels, round structures – of any radius – can be formed.

Minimum inside radius: 1.80 m

In the same way as with the wall formwork, all that is needed to connect the Framax circular forming plates to the Framax Xlife panels is the Quick-acting clamp RU – and a blow of the hammer.

A. Framax circular forming plate
B. Framax steel waling RD 0.40m
C. Framax quick-acting clamp RU o Angle
anchor plate 12/18 with Wing nut 15.0
D. Framax Xlife panel

Aerial view of Framax Xlife framed formwork system  

a … maximum tie-rod displacement = ±2.5 cm
A. Tie-rod 15.0mm
B. Wing nut 15.0
C. Angle anchor plate 12/8
D. Framax circular forming plate
E. Turnbuckle
F. Steel waling RD 0.40m
G. Quick acting clamp RU
H. Framax Xlife panel

Close-up view showing fixing of steel waling RD 0.40m
A. Steel waling RD 0.40m
B. Support and retainer for steel waling RD 0.40m
C. Framax circular forming plate


Circular Plate Specifications

Using the different widths of circular forming plate: .0.20 m
– Inside circular forming plate
– Outside circular forming plate (for length adjustment) .0.25 m
– Outside circular forming plate .0.30 m
– Outside circular forming plate

Doka Circular Formwork for Acrow

Formwork Example

• Type of structure: Circular tank
• Inside radius of structure: 3.00 m
• Wall thickness: 0.20 m

Simplified representation, without details of form-ties or panel struts.
A Framax circular forming plate 0.20m (for the inside formwork)
B Framax circular forming plate 0.25m (for the outside formwork)
C Framax circular forming plate 0.20m (for length adjustment, distribute evenly around circumference)
D Framax Xlife panel 0.45m (Note: same-sized panels are always used both inside and out.)

Closing the full-circle formwork

The remaining areas for closing a full circle can be formed in a number of different ways.
Around the perimeter, use panels of equal width wherever possible.
• In order for the load transferred via the steel waling RD 0.40 m to be as uniform as possible, adjacent panels may not have bigger width differences tha n those of the standard width grid .
• Any imbalances necessitate additional shoring.
The same is also particularly true of transition zones to straight walls, and of stopends. Careful, correct shoring and pouring is particularly important when working with circular formwork.


Determining key panel specifications

Determining the max. panel width
Radius segment diagram for the various widths of panel.
The radius segment diagram is for determining the max. panel width as a function of the radius and the permitted deviations from the circular arc.

TransparentCirForm09Determining the best distribution of the panels

Key data of structure
Inside radius [cm]:580
Outside radius [cm]:600
Permitted deviation from circular arc [cm]:1.0
Length of concreting section [cm]:911 (1/4 of the inside circumference)

Width of panel
Determine the max. panel width in the radius segment diagram with references to the radius of the structure and the permitted deviation from the circular arcPanel width = 60cm

Width of circular forming plates for inside formwork
As a general rule use the circular forming plate 0.20m with the inside formworkWidth of circular forming plate = 20cm

Widths of circular forming plates and numbers needed for outside formwork
( Length of concreting section – panel width | + ( Panel width + 20 ) -…( 911 – 60 ) + ( 60 + 20 ) – 10.64
Number of circular forming plates – Rounded up resultNumber of circular forming plates = 77
Number of panels = Number of circular forming plates + 1Number of panels = 12

Number of Circular forming plates and panels on one side of the formwork
{ Outside radius : inside radius | x ( Panel width + 20) Panel width -…( 600 : 580 ) x ( 60 + 20 ) 60 – 22.76cm
Select the next smaller Circular forming plate to be the "Type A" Circular forming plate.Width of "Type A" Circular forming plate = 20cm
Calculate the difference.Difference = (22.76cm – 20cm) – 2.76cm
Number of Circular forming plates x (1 – ( Difference / 6 ) = … 11 x (1-(2/(6/5))) = 4.93
Number of "Type A" Circular forming plates – Rounded-up ResultNumber of "Type A" Circular forming plates = 5
Number of "Type B" Circular forming plates – Number of Circular forming plates – number of "Type A" Circular forming plates – …Number of  "Type B"  Circular forming plates = 11 + 5 – 6
Select the next larger Circular forming plate to be the "Type B" Circular forming plate.Width of "Type B" Circular forming plate = 25cm

Erecting and Plumbing / Pouring / Moving

Erecting and plumbing
Panel struts ensure that the formwork remains stable against wind loads, and make it easier to plumb and align the formwork.
TransparentCirForm12Important note:
The formwork panels must be held stable in every phase of the construction work! Please observe all applicable safety regulations! For more information, please see “Plumbing accessories”.

TransparentCirForm13Pouring Scaffold
The Framax brackets 90 (A) can be used to make a universal pouring scaffold. For more information, please see “Pouring platforms with single brackets”.

Thanks to the spindle-lock, the formwork can be moved with the Framax lifting hook (A) even when assembled in a curved configuration.


  • The maximum size of the unit to be moved will depend – among other things – on the radius that has been set.
  • When moving larger gang-forms, ensure that these are sufficiently braced.
  • Prevent oblique pull, by using long transfer cables (spreading angle of lifting tackle ~: max. 60°).
  • Check that the slip-out guard of the Framax lifting hook has engaged!

For more information, please see “Lifting by crane”.

Please follow the directions in the instruction manual!

FRAMAX Steel and Aluminium

High performing galvanised steel-framed formwork for crane assisted forming of large areas and lightweight aluminium framed formwork ideal for forming with or without a crane.

  • Foundations For fast forming of slabs and beams
  • SCC Panels Pump SCC concrete from the bottom up
  • Stripping Corners Fast stripping shaft walls, tight corners
  • Xlife Ply Sheet Superior form finish, easy clean plastic face ply sheet
  • Formwork Pressure Up to 80 kN/ m2.
Steel Framax Xlife Panel Widths (cm)
Steel Framax Xlife Panel Widths (cm)

FRAMI Lightweight Steel

Manhandled steel-framed formwork, ideal for fast and economical forming of foundations, walls and columns, with or without a crane.

Allows for easy handling and easy planning.

  • Foundations For fast forming of slabs and beams
  • Stripping Corners Fast stripping shaft walls, tight corners
  • Xlife Ply Sheet Superior form finish, easy clean plastic face ply sheet
  • Robust Extra rugged build provides superlative, clean concrete results.
  • Formwork Pressure Up to 67.5 kN/ m2.

Top 50

The Doka large-area formwork Top 50 is designed to be tailored to many very diverse types of task – so it gives you ideal scope for adapting the shapes and sizes of the elements to suit your structure.

The element size-grid and tie-hole pattern provide the adaptability needed to accommodate architectural demands. The large-area elements and exact connections make for a perfect joint pattern.

You can choose whichever form-face material best meets your requirements – e.g. for smooth fair-faced concrete, wood-textured surfaces, intensive re-use etc. A range of practical accessories makes work on the site a lot easier and does away with the need for costly in-situ improvisations.

Doka will plan the most economical solution for you. Also, having your formwork pre-assembled by the Doka “Ready-to-Use Service” saves time and space on site.

0800 FORMWORK • 0800 3676 9675