Case studies matching "fibre reinforcement for concrete"

The Burj Khalifa – formerly the Burj Dubai – is a legendary building that can only be described in superlatives. At 828 metres high, it is the tallest building in the world. The Burj Khalifa has 160 floors, more than any building in the world. The building also has the highest floor, the highest façade made of aluminium and glass, the highest nightclub and the highest restaurant, the highest service lift and the lift with the longest travel distance. Finally, the building has the highest positioned revolving doors ever installed in a façade worldwide. In less than 30 years, Dubai has become the leading city in the Middle East and is known for its architectural and technical excellence. The Burj Khalifa has become the symbol of this progress. The Burj Khalifa also takes the title of the highest structure in the world back to the Middle East; the Great Pyramid of Giza used to hold the title 4 millennia ago. International Collaboration The tower was designed by architectural firm Skidmore, Owings & Merril, known for their designs for the Willis Tower (formerly the Sears Tower) and the new One World Trade Center in New York. The three-pronged design is based on the spider lily desert flower and consists of three elements around a central core, with the elements spiralling upwards. It can rightly be called an international project: the construction team consisted of Samsung Engineering & Construction employees from South Korea in collaboration with Besix from Belgium and Arabtec from the United Arab Emirates. The UK consultancy Hyder Consulting was responsible for overseeing construction of the building. In total, companies from more than 30 different countries contributed to the construction of the Burj Khalifa. A Windy Challenge The wind is quite a challenge when building a skyscraper of this size. Without additional measures, the top of the building would move so much from side to side due to the wind that people would become seasick. Dubai is also regularly tested by the shamals: sandstorms that can last for days. As the outer façade of the Burj Khalifa contains an enormous amount of glass, these weather conditions presented a considerable challenge. The three-part design proved to be the solution because the spiral floors break the wind currents around the building, resulting in a stable structure. The World's Highest Revolving Doors Skidmore, Owings & Merril's design includes an observation platform on the 124th floor of the building. Two glass revolving doors provide access to this room. At 442 metres above the ground, these are the highest positioned revolving doors ever installed in the façade of a building. The revolving doors must also be able to withstand an extremely high wind load of at least 3000 Pascal, which corresponds to an F3 class tornado. The Burj Khalifa required two automatic revolving doors with a diameter of 3,000 mm and a total height of 2,700 mm; the cover could only be 300 mm high with the motor installed. Generally speaking, a revolving door with these specifications would only be able to withstand wind loads of up to 689 Pascal. It was clear, then, that not every revolving door manufacturer could supply an entrance that met these requirements. Challenge Accepted Koninklijke Boon Edam was one of only two companies invited to devise a system for this challenge. There were two main problems that had to be solved: the round sides of the revolving door had to be strong enough to resist the wind, and the door set had to be properly fixed so the door wings could not be blown off during a storm. Boon Edam worked closely with Mace, the Hyder Consulting Group, Samsung Engineering and Construction and Turner Construction, the subcontractor, to develop a system that met all these requirements. During the first phase of the process, the second company invited to tender had to give up because their design did not meet the challenging conditions on the 124th floor. Boon Edam persisted in its efforts, and after conducting various wind load and glass tests, it became possible to adapt the construction of the Tourniket to the requirements of the Burj Dubai. A Tornado-Proof Revolving Door at the Burj Khalifa Our proposal for the Burj Khalifa consisted of a Tourniket with specially reinforced door frames twice the width and thickness of a normal revolving door. These were securely anchored with special bolts under the floor to guarantee the structure's rigidity. Although most revolving doors are installed on the top of the subfloor, this door was installed under the top finish layer of the concrete floor. To guarantee the stability of the door set, an extra-thick steel frame was added to the structure. This allows the door wings to easily withstand the wind pressure. Expansion on the 148th Floor in 2014 Boon Edam installed the same specially designed Tourniket revolving door on the 148th floor as on the 124th floor. However, the new project brought an extra challenge: transporting all of the materials from the basement of the building to the 148th floor. First, the materials had to be transported in one lift to the 111th floor. They were then transferred to a second lift, from where everything had to be moved manually from the 149th floor to the 148th floor, to the door's location. Special Projects Based on Standard Solutions The revolving doors we created for the Burj Khalifa were an extreme challenge. The experience and expertise of our technicians combined with the tried and tested technology of the Tourniket enabled us to develop a successful solution. Both revolving doors are now used daily and give visitors a spectacular view of Dubai. The glass design beautifully complements the modern façade of the observation platform and puts Dubai's beautiful skyline in the spotlight.