Accurate, scientific testing of concrete and other construction materials has enabled massive advances in civil engineering in recent decades. Far from being just a low-tech solution for small-scale projects and domestic builders, concrete features in some of the most exciting architectural projects around the world.
All this is due to our ability to study and measure the properties of concrete using standardised, scientific measurement systems.
As the predominant building material in most modern towns and cities, concrete would seem to be a product of the industrial age, and indeed, the first modern concrete dates back to the nineteenth century, with the invention of Portland cement by English inventor Joseph Aspdin, in 1824.
Reinforced concrete, as we know it today, was invented by a Parisian gardener, Joseph Monier, who received a patent for his invention in 1867. He used steel mesh to reinforce his concrete pots, and steel is the major reinforcing material used to this day.
We can go back a little further, to 1756, to find British engineer John Smeaton’s first ‘modern’ concrete, which included pebbles as a coarse aggregate and powered brick, but with a lime cement. However, the Romans had a form of concrete and combinations of crushed lime, clay and various aggregates have been utilized in many civilizations across the centuries and around the world, including ancient Egypt, who used lime and gypsum, and Babylon, where clay was used instead of lime.
Reinforcing of a plastic or semi-liquid building material is not a modern idea, either. For centuries, builders have used straw, hair and other fibres to add tensile strength to different types of building materials, from clay daub to lime-based cements.
Earnest L. Ransom patented a reinforcing system using twisted rods rather than mesh in 1884. This twisting improves the adhesion between concrete and steel, which greatly increases tensile strength.
This reinforcement is needed under any circumstances where tension is likely to occur, even in modern high-quality concretes, since these materials have a very high compressive strength but relatively low tensile strength, and combining these two superb materials gave us a building material second to none.
However, pre-stressed concrete (where the steel rods are held in tension while the concrete mix is setting) is a more modern invention, being invented only in 1928. A pre-stressed concrete beam will have a slight curve to it, and will effectively support its own weight without strain and without developing the hairline cracks in its lower surface that an unstressed beam will inevitably develop.
Thanks to precision engineering and the application of science and technology, the qualities of every concrete component can be modelled and predicted, and architects and engineers can use these components with confidence.
Furthermore, with the advent of accurate testing equipment, and the industrial production of consistent raw materials, we can now predict exactly how concrete will behave under almost all circumstances, from extremely high temperatures to very low ones, and from a dry environment to a submarine one.
It’s this ability to test and predict the characteristics of concrete that enables engineers and architects to push the boundaries of concrete construction and transform city skylines around the world, as well as creating industrial facilities and civil engineering projects in a fraction of the time, and with far less risk of mishap or disaster, than was possible just a few decades ago.