Cement or Concrete - What's the Difference?

Cement or Concrete - What's the Difference?

15th December 2015

Here at Safety Fabrications we've been looking into concrete for the past few months, bringing our readers as much information as we can about this substance that has transformed the building trade throughout history. We've looked at the history of concrete, how it was originally discovered by the Romans, we've followed on with information about the use of concrete in modern times and we've also looked at the new types of concrete that are becoming available. As concrete technology progresses, it's proving that it is still one of the most versatile construction materials and will continue to be so in the 21st Century as progress in concrete technology ensures that it is becoming even more useful land environment friendly than ever before. Today we're going to take a look at the difference between concrete and cement – two words that are often mixed up (forgive the pun).

First of all we're going to concentrate on the difference between concrete and cement. In general terms, cement refers to any kind of binder that holds other materials together – whereas concrete is a mixture of materials such as gravel, sand and small rocks combined with any type of cement and water. Once mixed, the concoction is left to dry and harden until it becomes a stone-like structure that's formed after cement and other materials are mixed together. Cement is just part of the recipe that makes up concrete.

Cement was discovered by the Romans as we pointed out in our History of Concrete article some time ago. Cement has been used as a binder material throughout history and has been one of the materials that has allowed mankind to develop the techniques required to build massive structures such as the cathedrals of the Middle Ages.

These days, cement comes in two forms – Hydraulic and Non-Hydraulic. Hydraulic cement is the name given to any cement that uses water to spark off the chemical reaction that caused the mixture to harden. When fully formed and set, this creates a water resistant product that enables buildings to withstand harsh weather conditions. The chemical reaction that's occurs happens independent of the water content of the mixture which means that cement can harden even underwater, making it an extremely versatile construction material. Most cements in use today are hydraulic cements.

Non-Hydraulic cement uses materials that don't harden when exposed to water. Although it's cheaper to produce than hydraulic cement, the long drying times required coupled with the fact that it is not suitable for use in wet environments means that it's not a popular choice for construction.

The most common type of cement is Portland cement (often referred to as OPC – Ordinary Portland Cement) which is produced by grinding small rock like pieces of sintered limestone and aluminosilicate minerals into a fine powder. It has a rapid drying time and boasts a higher compression strength when compared with other types of cement so it's the most popular choice for use in concrete, grout, mortar and stucco.

While most people use the words cement and concrete interchangeably, they are not the same thing. As we have shown, cement is just one of the components of concrete.