Once upon a time (not so long ago), the Burj Khalifa was just concrete under construction - a very different sight from today ...

In November 2007, the highest reinforced concrete core walls were pumped using 80 megapascals of concrete from the ground level. Concrete was pumped up to a remarkable 601 metres. Old pictures of Burj ...

It’s also the reason the Burj Khalifa started coming together so fast. Less than a year after Emaar had selected Smith and SOM to design the supertall structure, they’d broken ground.