A Brief History of Concrete

What is concrete and how long has it been around?

Basically it is a mixture of sand, water, cement and gravel, also known as aggregate used in building and construction more than any other material. Many different materials are used for aggregate including stone chips, gravel, clay, even rubble is used sometimes, depending on the application it is required for.

It was first used in Britain in the early 1800s, although very similar mixtures date back to the ancient egyptians and babylonians. They used a mixture of clay and sand with a cement based on lime to build structures with thousands of years ago, then later the romans used something very similar mixing sand and volcanic ash together with lime. This actually held together very well due to the cementitious properties of the aluminium and calcium hydroxide present in the mixture as a result of the very high temperatures the volcanic ash had already experienced. 

They used this material to great effect in the construction of the Pantheon, particularly the roof which was due to the advances they had made in producing lightweight aggregates had the ingenious use of bronze in the underlying superstructure. As they didn't have steel in those days and they were unaware of the chemical reactions that were taking place inside the structures they knew nothing of the spalling effect due to the differences the two materials had in terms of thermal expansion over time, still, highly innovative and well ahead of their time.

The first ever recorded use of concrete was first mixed by John Smeaton, an English engineer in 1756 - it was made by mixing powdered brick and pebbles with cement. Then later on also in England the inventor Joseph Aspdin invented the first modern cement by mixing clay and limestone together at high temperature, and is basically the same compound that is found in modern cement today - it's called Portland cement.

The aggregate aspect of concrete depends on the purpose it is being mixed for - finer aggregates such as fine sand, ash, fine gravel would be used to make slabs and flat surfaces such as walkways etc whereas the coarser material like stone and gravel will be mixed for larger structural components. Either way it is highly desirable and convenient to transport, mix and pour to render a hard wearing strong building material.

Another material that can be mixed into concrete is steel which is referred to as reinforced concrete. First tested by Joseph Monier in Paris in 1849 he used  a type of steel mesh to reinforce the concrete to support heavy plant pots. These days concrete is poured over steel structures and used for all kinds of construction including motorway bridges where strength and longevity is needed.

Concrete is used to make prefabricated building components off site which has revolutionised the construction industry since the early 1900’s in the form of concrete blocks and large scale water and sewer pipes. Many large structures are prefabricated from concrete that is poured into moulds or forms before finishing and storing ready to be transported to the site for assembly.