It is stronger than steel-framed skyscrapers because to its reinforced concrete construction. See also: Geotechnical Engineering. The structural concrete Burj Dubai was purposefully constructed—"Y" shaped in plan—to decrease wind pressures on the tower, as well as to make the construction basic and promote constructibility. It is estimated that the weight of the stone alone in the Tower would sink it if it weren't for the reinforcing bars inside the concrete. The building has been criticized for using a lot of concrete, but only because it contains more metal than wood or other materials used in architecture today. Concrete is both strong and light, so it's very useful when building large structures, and it has the added benefit of being recyclable. There are actually recycled plastic bottles embedded in the flooring of the lobby! Another advantage of using concrete is its durability. The Burj Khalifa will be around for centuries after it is built since concrete lasts naturally over time through weathering and erosion. Wood tends to rot away over time too though it can be preserved with paint or another protective layer. Finally, concrete is easy to work with. No wood frame means no risk of warping from uneven heating and cooling during construction or after you move in. Plus, there's no need for special tools or expertise to build this kind of structure.