When it comes to commercial construction, builders and designers are scoping out new ways to improve efficiency, save money and have more streamlined construction sites. One proven solution is choosing permanent formwork as an alternative to conventional masonry block, precast concrete or in-situ building methods.
In traditional in-situ concrete construction, the formwork is removed once the concrete is strong enough to stand on its own. Removing this formwork can be a delicate and labour intensive job and great care is needed to make sure the structure is not compromised during the removal process.
Permanent formwork, on the other hand, requires minimal bracing compared to in-situ pours and cuts out the need for bricklayers. The formwork is left in place after the in-situ concrete has set to create a permanent structure. This labour saving process is one of the major reasons permanent formwork is becoming so popular, especially in the commercial sector where buildings may be large or multi-storey structures of significant complexity.
Many permanent formwork systems on the market use prefabricated lightweight hollow panels or blocks that join together to form walls that have steel reinforcement placed in them and are core filled with concrete. For example, manufacturers offer permanent formwork solutions in polyvinyl chloride, fibre cement, polymer or other similar patented materials.
One leader in permanent formwork is AFS Systems with their Logicwall and Rediwall walling solutions. Logicwall is a fibre cement based permanent formwork system that can be used for both external and internal application. It consists of lightweight panels created by bonding hard-wearing CSR Cemintel fibre cement sheets to galvanised BlueScope steel stud frames. The panels are delivered with shopdrawn accuracy and feature corresponding labels for easy installation. They are load bearing but lightweight enough for manual installation. The panels provide reliably flat, true surfaces to help deliver high-quality finishes.
The Logicwall can be seen in action at The Fiddler Hotel in Rouse Hill in Sydney.
“When expanding the offer from The Fiddler to include a 4.5 star hotel and new function facilities, it was essential that we sourced products that could meet our need for exceptional quality and, from our experience using AFS Logicwall, we knew it was the right choice for this project,” Contracts Administrator at Growthbuilt Eddie Abousleiman explained.
We used Logicwall in external and internal wall applications throughout the build and we relied on HD Projects (an AFS Certified Logicwall Installer) to complete the installation with precision whilst ensuring that our project timeline was met”.
“The result was sensational, and we handed over an exceptional, high-quality hotel to our clients Lewis Land Group,” he says.
Another happy customer is Woollam Construction who used Logicwall at University of Sydney, Lismore Campus.
They used AFS Logicwall as finished walls from the common areas through to hallways and bedrooms.
“The Logicwall system provided us with a superior program advantage and significantly reduced our ceiling partitions contract as we could simply set and paint the walls,” the Woollam Construction company says.
“Our client, University of Sydney, likes that the Logicwall system is a finished wall and is extremely hard wearing in this high traffic student accommodation, along with the significant reduction in maintenance requirements compared to conventional batten and sheeted walls.’’
The AFS Rediwall on the other hand, is a PVC permanent formwork system. The extruded components either simply snap or slide into place, automatically interconnecting for rapid assembly and achieve an attractive, low maintenance wall surface. It requires almost no machinery-aided installation. And with its high-quality semi-gloss finish, it generally requires no extra finishing in many applications.
Another innovative product on the market in the permanent formwork domain is the Insulbrick ICF Building System. The construction system by The Insulating Brick Company is used to build walls for domestic and commercial structures and is made from expanded polystyrene (EPS) formwork and reinforced concrete.
The Insulbrick ICF walls simply interlock together like lego blocks. The intervals they interlock ensure that vertical cores of concrete are always continuous therefore creating the concrete wall at its optimum strength. The insulbricks can be easily cut with a handsaw or with specialised hot wire cutters. When properly braced both the Insulbrick ICF 200 and the Insulbrick ICF 240 can be poured up to three metres at a time.
Insulbrick says ICF wall construction is “quick and easy”. When interlocked and filled with concrete, they create a solid wall with remarkable insulating properties for both internal and external walls. Using Insulbrick ICF over traditional bricks and mortar walls comes with the added benefit of saving money on the speed of construction.
The Insulbrick is also known for improving acoustic performance and customers are not limited by choice as far as external finishes which can be done in stone, cladding, render, timber and Colorbond.
Insulbrick ICF has been a popular choice among those building wine cellars. One of the ICF’s latest winery projects was St Andrews for Buttermans Track Wines in the Yarra Valley. Owners Gary, Louise and Joel Trist dropped ICF a line to let them know they were in the process of constructing a small winery on their property in St Andrews and that they had planned to use ICF primarily due to its superior thermal properties.
“Our winemaking philosophy is minimal intervention, so we wanted to ensure we built our winery with the same philosophy,” owner of St Andrews for Buttermans Track Wines Gary Trist said.
The winery is built on three levels to accommodate gravity flow winemaking thus eliminating the need for pumps. The barrel room is more than 50 percent in ground to provide good thermal mass and stability.
Trist explained that access to their site was also limited so they had to find a building technique that was flexible, did not require huge cranes and material handling equipment but could also suit inground and above ground construction.
“The ICF system provided by Insulbrick met all these criteria and their support, professionalism and attention to our detailed construction requirements was outstanding,” he says.
ICF is widely used overseas where the temperature fluctuates from very high to very low degrees in temperature and constructions built using this system maintain a steady temperature inside. The building system provides a continuous layer of insulation and is an excellent cold storage facility, maintaining the constant 17 degrees Celcius temperature needed to store wine.
All the walls in a cold storage facility must have no empty areas where rats, mice or insects could nest, therefore this creates a perfect scenario for the use of ICF construction since the foam is the insulation and the concrete wall becomes your structural element and there is no void between the two materials.
“Since the winery has been finished, we have found it has met all our design criteria, the inside temperature has been extremely stable ranging from a minimum of 17 degrees in winter to a maximum of 21 degrees in summer,” Trist says.
“As hoped, there has been no need for supplementary heating or cooling which has also kept our operational cost down.”
As permanent formwork grows in popularity in Australia new players are entering the market Down Under. Airdeck, which was founded in Europe, is now open for business in Australia. The flooring solution is marketed as a hybrid or semi-precast solution and consists of large concrete elements on which Airboxes are installed. These Airboxes are made from recycled polypropylene and act as void formers, working to create lightweight building structures.
Airdeck allows structures to be built with large spans and the extra benefit of omitting beams or supporting walls. This creates flexibility for buildings that have a lot of mechanical, electrical, and plumbing (MEP) to be incorporated in the building structure, like hospitals, schools, laboratories. With flat soffits, there’s maximal spacing in the fake ceilings to integrate MEP.
Airdeck also develops drilling protocols for each floor to allow corings even next to columns. This solves a lot of issues that certain buildings are facing when they are trying to install or extend their MEP or even to remodel complete wings.
Airdeck was developed to create weight savings compared to a solid CIS floor, in combination with more flexibility in the long term. The product is delivered on-site with a 6 or 7cm concrete plank, including the Airboxes which guarantee concrete savings up to 32 percent. The Airbox can hold a point load of up to 180kg and is safe to walk on.
A contractor installs the necessary upper and joint reinforcement. The top concrete layer is casted the traditional way. Next to the concrete, there’s also considerable savings in labour on-site as the product is fabricated off-site and eliminates typical handling like formwork. Post tension is not required except on very large size slab spans.
Semi-precast is specifically interesting as it creates wet nodes around the columns which is a good solution for the current earthquake approach of buildings in the new AS3600. Airdeck floors are always customised. Depending on the desired spans and the constructive frame building concept. Airdeck is also a sustainable solution which uses less concrete, steel, water and transports when building.
The Airdeck product has been particularly popular for building hospitals. An example of this can be seen at the new ZNA Hospital in Antwerp, Belgium. The build of this hospital is quite unique, because it is one of the first high-rise hospitals in the country. The hospital has 21 floors, of which 19 are above ground. The total surface of the project is almost 100,000sqm.
Airdeck was selected as the lightweight floor system for the total hospital structure, including the underground parking. Flexibility in the project was very important and Airdeck came up with a tailormade drilling protocol to allow future drillings in the hospital building structure.
The contractor was also able to have a faster construction speed using Airdeck as opposed to more traditional building methods. On the ground level, the tram is making a new connection in the Antwerp area. The tramway itself was also installed on top of the Airdeck elements.
Ultimately, as the construction industry looks for more ways to reduce costs and increase efficiency and sustainability, traditional methods for load bearing walls and floors may not suffice. This is where permanent formwork steps in, creating faster, more cost-effective solutions that can also increase the safety, durability, flexibility and sustainability of a build particularly in terms of large scale more complicated commercial projects.
Image: The Mean Fiddler Hostel / Afs Systems.