The History Of Concrete
Concrete has been in existence in varying forms for thousands of years. The oldest concrete discovered was in the floor of a hut in Israel, dated around 7000BC. The concrete used for the floor was made by burning limestone to produce quicklime which was then then mixed with water and stone and left to set.
Knowledge of this lime-based material spread through Egypt and Ancient Greece and reached the Romans around 300BC. The very word concrete comes from the Latin ‘concretus’, meaning grown together or compounded. The Romans discovered a volcanic material that had cementing properties, known as Pozzolanic cement. Examples of concrete made with this cement still exist in structures such as the Pantheon and Colosseum in Rome.
The birth of modern concrete as we know it today can be attributed to a stonemason from Leeds called Joseph Aspdin. He made a new, improved cement in 1824 by heating chalk and clay together then grinding it down to fine powder. He called it Portland Cement due to its resemblance to Portland stone in the hardened state. It was the most superior cement of the time, producing greater strengths than were previously possible. The mass production of this cement began in 1828 and the concrete explosion began.
Concrete inspires numerical superlatives when describing its ubiquity: Slightly more than a ton of concrete is produced every year for each human on the planet—over six billion—with Americans responsible for 2.5 tons per citizen. Produced at an estimated rate of five billion cubic yards per year, concrete is the second most widely consumed substance on earth after water. Concrete is the world’s oldest man-made building material. Yet, it’s the material’s dual personality that makes it both ubiquitous and appealing. Since the Industrial Revolution, concrete has been the robust, utilitarian workhorse for constructing bridges, tunnels, aqueducts, sidewalks, roadways, and barriers. Modern concrete is reinforced with steel and other materials, poured-in-place, precast, pre- and post-tensioned, tinted, molded, embossed, polished, and drilled. In its most modest state, it provides a building’s structure, which is then hidden behind a prettier skin. But it can also be a glamorous material, especially when it performs simultaneously as structure, form, and surface.