The Burj Khalifa is supported by which type of core using a special concrete mix?

• A. Timber Core
• B. Composite Core
• C. Reinforced Concrete
• D. Steel Core

Answer: (C)

The main idea is that the stability of a megatall building relies on a strong, stiff core that resists gravity and lateral wind loads. Burj Khalifa uses a reinforced concrete core built with a high-strength concrete mix, formed in place and heavily reinforced to provide both strength and ductility. This solid concrete core acts as the central spine, giving the structure substantial stiffness to limit sway and to transfer loads efficiently to the foundation. The concrete can be pumped to great heights and poured to create a continuous, monolithic core that also offers good fire resistance. A steel or timber core wouldn’t provide the same combination of mass, continuity, and fire performance at this scale, and a composite core isn’t what's used here. The reinforced concrete core, with its special high-strength mix, is the best choice for these structural needs.