Inside the engineering behind Egypt’s tallest building, built on a single concrete raft

Building the Iconic Tower, the 385-metre skyscraper at the heart of Egypt’s New Administrative Capital, required engineers to solve a genuinely difficult technical problem: casting the entire foundation as a single, uninterrupted mass of concrete strong enough to support Africa’s first supertall building.

Architecture and engineering firm Dar Al Handasah Shair and Partners designed the tower and supervised its construction, carried out by China State Construction Engineering Corporation. The tower’s steel skeleton rests on a semi-circular reinforced concrete raft laid directly onto a basalt rock layer, measuring 3,710 square metres in area and five metres thick, for a total volume of roughly 18,500 cubic metres, with reinforcement adding around 4,600 tonnes of steel to the structure.

To manage the intense heat generated as that much concrete cured, engineers built a 5x5x5 metre mock-up beforehand to measure the heat of hydration, used a cement mix incorporating silica fume specifically to control that heat, and ran a full 8,500 cubic metre trial raft on a separate tower first to test the entire casting plan before attempting the real one.

The tower forms the centrepiece of a much larger Central Business District that includes six additional office towers, five residential towers and two hotel towers, part of a roughly 700 square kilometre new capital city that Egypt has built from scratch in the desert east of Cairo.