The most mundane things that you use every day (think post it notes, rubber bands, concrete) often have fascinating stories behind them.
In fact, people often only notice how something's designed when it goes wrong. But the process of discovery, testing and prototyping anything, no matter how ordinary, is full of pitfalls and the occasional exhilarating breakthrough.
Concrete
Concrete has existed almost as long as construction itself - an early form of the sand and gravel mix was found used as the floor of huts built on the Danube over 7,000 years ago.
But it wasn't until 19th century bricklayer Thomas Aspdin invented Portland cement that concrete was widely used for anything else. By overheating a mixture of three parts limestone and one part clay, he found the chemical properties of the substance changed. Mixed with water, it set incredibly hard. With the addition of sand and gravel, it became concrete.
Concrete had to be used with care, though, as it was strong under compression but not tension. It wasn't until French gardener Joseph Monier accidentally invented reinforced concrete in 1867 that it could be used in load-bearing structures. Fed up with his clay pots cracking in winter frosts, he added chicken wire during their manufacture. It worked, so he tried strengthening concrete with it, too. Architects have never looked back.
Alec Issigonis