FAQ

1. Concrete is the most-used material in the world
It may not come as a surprise to discover that concrete is incredibly widely used; it is, in fact, used more than any other material in the world – perhaps because the aggregates and water used to create concrete are available virtually everywhere. However it might be more surprising to learn that 20 billion tons are put to use every year, with China being the largest consumer of concrete in the world, responsible for half of the world’s concrete annually!

2. Concrete and cement are not the same
To think ‘concrete’ and ‘cement’ are identical is like saying flour is the same as cake. Only around 10-15% of concrete is cement, which is itself mostly made up of lime; between 60% and 65% is made up of an aggregate such as gravel or sand and 15-20% is water.

3. The Ancient Romans perfected concrete – and it still stands today
It formed naturally in Israel twelve million years ago, and the Ancient Egyptians used a type of concrete in the pyramids at Giza; but it was the Romans who captured the knack of concrete. Most famously, the Pantheon in Rome, built in around 120 AD, is still the largest unsupported concrete structure in the world.

4. Portland Cement is named after the limestone of a similar color
Developed in 1824 by Joseph Aspdin, Portland Cement is widely used today as the aggregate for most concrete. Aspdin heated limestone and clay to produce a render, which could pass for the sought-after limestone Portland, Dorset. He quickly discovered it could be used for house building and patented the material.

5. Concrete was used to detect enemy aircraft in the Second World War
Remarkably, concrete “sound mirrors” were used at the beginning of the Second World War to provide an early warning of approaching aircraft. Initially they had microphones attached, and had an impressive aural range of about 27 miles.

6. Incredibly high compression strength
Concrete commonly reaches between 3,000 and 7,000 psi (pressure per square inch), though can reach as much as 20,000 psi. The fact that the Colosseum, Hadrian’s Wall and the aqueduct at Pont du Gard in the south of France are all still standing is testament to being built using concrete. When reinforced with steel, it is even more sturdy and more rigid.

7. Concrete was named by the Romans
The word ‘concrete’ comes from the Latin word ‘Concretus’, which roughly translated means, appropriately, to ‘grow together’.

8. Concrete is used for motorway bridges and high-rise buildings
Almost all motorway bridges use concrete for decks, because they are both easier to maintain and cheaper than steel. It remains in use in the construction of high-rise buildings; the tallest concrete structure in the world is the Trump International Hotel and Tower, standing at 423 meters.

9. Concrete continues to strengthen for decades
After around four weeks, concrete has reached around 90% of its final strength. However it continues to strengthen for decades afterwards, due to the conversion of calcium hydroxide into calcium carbonate, due to its absorption of carbon dioxide over time. Some bacteria also help to strengthen concrete!

10. It took 16 million cubic meters of cement to make the world’s largest dam
The Three Gorges dam in China’s Hubei Province is the largest concrete pour in a single project – but this was no one-off pour. In the 17 years of construction time, almost one million cubic meters of cement per year was needed.