Materials & Techniques: fun facts and quiz

Arches carry weight by pushing it sideways into their supports. The Romans used them in aqueducts and bridges, and a dome is like an arch spun in a circle.

Key fact
The top stone of an arch is called the keystone.

People have built with fired bricks for thousands of years. Stone lasts even longer, and many medieval cathedrals took over a century to finish.

Key fact
Cologne Cathedral took over 600 years to complete.

Steel frames carry a building’s weight, so walls can be thin and full of glass. That made modern office towers and huge glass facades possible.

Key fact
London’s Crystal Palace of 1851 was an early giant of iron and glass.

Concrete is strong when squeezed but weak when stretched. Steel bars inside, called rebar, handle the stretching: that’s reinforced concrete.

Key fact
A French gardener, Joseph Monier, patented reinforced concrete pots in 1867.

In earthquake zones, buildings may sit on rubber bearings or springy bases that let the ground shake beneath them, protecting the structure above.

Key fact
This technique is called base isolation.

Some buildings are made from factory-built parts, then put together on site in days. Houses can now even be 3D-printed from concrete.

Key fact
A Chinese firm put up a 57-storey tower in 19 days using prefab modules.

Roman concrete, made with volcanic ash, has lasted 2,000 years, even in seawater. Scientists found it can partly heal its own cracks.

Key fact
Rome’s Pantheon still has the largest unreinforced concrete dome.