Advice

What is the lime in concrete?

Lime, in concrete? 

If you are aware of concrete construction, you might be aware of the use of lime in concrete. And you might be asking, why add lime to concrete?  

Well, lime has been used as a construction material since 4000 B.C. It was used extensivly by the Romans and even by the Egyptians for plastering the pyramids! So, why does lime mix with concrete so well? 

What is the lime in concrete?  

Lime in concrete has more beneficial properties than straight concrete mortar. It is these qualities which make it a superior choice due to its ability to withstand extensive weathering.  

Believe it or not, the lime in cement is what allows the cement to remain strong. It has been one of the binding elements of concrete that has made it the most reliable building material. In fact, besides water, concrete is the most widely used substance on Earth.  

But back to lime. Lime is a versatile material which isn’t just used in cement construction. Hydrated lime is used in various construction, environmental, industrial and chemical applications.  

In construction, lime in concrete is used to stabilise roads, airfields, building foundations and dams. Even more than the use of lime in cement, it is used the most in steel manufacturing to reduce the impurities in the steel matter.  

Why do we use lime with cement? 

Lime in concrete works to reseal any cracks that form in the mortar due to building movement. Lime based mortar is flexible and less brittle than other mortars, which means the softer bricks are less likely to break. Due to this softness, it also means it can easily be removed with less damage.  

Our mix of cement incorporates sand to give the strongest foundation possible. With lime based mortar, it helps the two combined elements to remain strong and work effectively in conjunction. This strength allows the concrete to stand the test of time against either harsh elements, whether it is the freezing cold or extremely hot.  

Lime based mortar is also more breathable! When there are damp conditions around a structure, there is a possibility for moisture to get into the walls. In a worst-case scenario, this could lead to mould inside your walls. When lime is in concrete, it is breathable, allowing the water to escape quickly and easily. Lime in concrete aids its water resistance, which stops the concrete structure from crumbling. 

If it is good enough for some of our world’s most ancient structures, it is good enough for us. We hope you’ve learnt why we use lime in our cement mix!