Formwork and BIM. What are they?
History of formwork systems
The boundless world of formwork dates way back in time. In order to learn more about it, let’s dive into some history, back in the day when a concrete-like compound was conceived. Basically, this compound was liquid material, hence the use of a mould was mandatory so for the structure to actually take shapes.
In ancient Egypt, timber formwork would be used for the solidification of this kind of “ancient concrete”, which most of the greatest pyramids was built with, including the flat-roofed one in Giza.
The concept of formwork was likewise well known among Roman architects. As a matter of fact, they used to build concrete structures with the addition of a siliceous material called ‘pozzolan’ mixed with lime, known as ‘betonium’. The Romans would erect two parallel walls where ‘betonium’ would be poured in. By doing so, once solid, the walls would become one thing with the compound and subsequently, turn into wall formwork themselves. This type of work was known asthe “Roman rubble masonry”.
The most significant structure of the time, pretty much the same that we can appreciate today, is the dome of the Pantheon in Rome.
Cross-section of the Pantheon, Rome
The Romans not only conquered, but have also spread their culture. To that end, the use of formwork was extended to the invaded populations. That is how construction systems began to be more and more applied and improved up to the present day.
Formwork – what is it? and what for?
The formwork is one of the most adopted auxiliary elements during one of the most important phases in the construction of any structure. Let’s learn the ropes of this incredibly functional system.
The formwork is a temporary element, so-called mould, into which concrete or similar materials are poured. Its job is to support the material during the setting and hardening process. It also plays an important role in giving the structure the final, desired, geometrical shape.
It finds application in any type of construction: from simple houses to larger structures such as bridges, viaducts, tunnels, etc.
Timber formwork has always been the prevailing design for reinforced concrete. Although this material is light, breathable, easy to work with, it cannot be used more than 5 times, under special conditions even 10. Interestingly, formwork systems today are largely made of metal, mostly steel, galvanised or painted panels, meaning they can virtually be reused as many times as you like.
The formwork systems may be divided into two main macro-categories according to their position on site:
- horizontal
- vertical
Horizontal panels
These are structures supported by vertical elements, props, and used to form floors, slabs and beams. This type of formwork panel is the one involving greater risks of falling from a height.
Aludeck slab system – CONDOR –
Vertical formwork
It finds application in the construction of pillars, walls and columns. According to the stress transmission, it is classified as either “single-sided” or “double-sided” formwork.
The single-sidedformwork is a system whose one-half side (face) does not exist and the concrete pressure is absorbed by structures outside the system (used for the construction of basements, cellars, galleries, etc.).
In the case of double-sided formwork, the concrete pressure is absorbed by both sides, thus favouring the creation of walls, columns, pillars, etc.
Adatto Alu formwork – CONDOR –
OPTIMO formwork – CONDOR –
More in-depth information on the formwork categories coming soon.
Formwork and BIM
As with the entire life cycle of a building (planning, construction, commissioning, operation, maintenance, restructuring and demolition), BIM may be a resource to design and organise the use of formwork systems just as well. When it comes to projects worth more than a hundred million euros, Building Information Modelling is mandatory in Italy and will gradually become mandatory for everyone over the next 5 years. In truth, by 2025 even the smallest studios will have to create their designs according to the BIM methodology, exploiting all of the advantages it brings.
Thanks to the BIM and the virtual simulation of both the model and the process, an optimisation of the formwork system is made possible prior to the construction, allowing the discard of any inconsistencies before commissioning.
Unquestionably, one of the greatest advantages in using the BIM is the access it grants to all of the data relating to the individual systems and components of the formwork (number of items, description, weight, etc.).
