First phase departure

Located 35 kilometres to the north of Istanbul on the European side of the Bosporus, Turkey’s most populous city is in the final stage of construction for its third airport and if there’s a common theme with this project, it’s massive. Built in the Arnavutköy district, the site alone covers 76.5 km2 and upon completion will be able to handle the same passenger volumes as London’s four international airports of Heathrow, Gatwick, Luton, and Stansted combined. Designed to become a hub for the region, it has attracted the interest of several airlines as a potential headquarters and its integrated port on the Black Sea make it all the more appealing to cargo operators. The planning behind such a major infrastructure build originated with the logistical issues of expanding the city’s two existing airports, Atatürk and Sabiha Gökçen and as a result, the former will be closed once the new ‘Third’ becomes operational. Construction started on the mega-airport in 2015, during which time Doka Turkey has been responsible for approximately two-thirds of the total formwork requirement in the first phase, which includes delivering both the main and second terminal, covering 850,000 m2. Once delivered, the first phase will include three runways and sufficient capacity to handle up to 90 million passengers a year.

As part of Doka Turkey’s service provision, the team was strategically involved since the pre-construction phase meaning its engineers were able to provide the most suitable solution for the overall project. One of the combinations that has been widely used on the project are Timber formwork beams H20 eco and H20 top and load-bearing towers, plus Framed formwork Framax Xlife and Frami Xlife and Large-area formwork Top 50. The load-bearing tower frames are made from steel, making them suitable for high clearances and loads, something that’s been particularly important on this project due to the length of the down stand beams (12 m) that are required to support the precast slab. Thanks to the width, strength, and easy vertical stacking feature of the towers, this solution has certainly helped to keep the overall project on schedule.

Everything about this project is massive, and the volume of formwork is no exception. Doka’s optimised solution proved that 30,000 load-bearing tower frames and 100,000 running metres of Timber formwork beams H20 eco and H20 top were required in order to deliver the project on time, with the load-bearing towers being specifically designed to be oversized for material-saving use, meaning fewer frames were required to prop the structure at any given time.

Framed formwork and Timber-beam formwork systems were used for the walls and columns with the lightweight and easy-to-handle Frami Xlife used for walls and Top 50 for the columns. Framax Xlife steel framed formwork was used for the forming of large areas that required a crane-lift.

As always, safety comes first when designing any formwork solution – for this project, stair towers enabled the site-crews to reach their workspaces quickly and approximately four kilometres of Edge protection system XP was used during the peak of labour. In addition, Doka Turkey provided Formwork Instructors who conducted on-site support and explained how to use the formwork effectively and safely.

Doka Turkey’s solutions were used on the runways, terminals, multi-level car-parking facilities, hotels, and the wastewater treatment plant. It is anticipated that the full project, which includes four phases, will be delivered in 2028 at which stage the airport will include six runways, 16 taxiways, 1,500,000 m2 of indoor area, and parking
for 70,000 cars.