Concrete vs Cement

Concrete is the world’s most used construction material second to water; however, it is often confused with an element used to make it. Rock Solid Concrete explains all.

Concrete and cement, two words interchangeably used for the same meaning, right?  

Wrong. 

Admittedly concrete and cement are intricately linked and related but also vastly different at the same time.  

Fundamentally concrete is a composite made from several materials, one of which is cement with cement being the bonding agent combining all the materials to make concrete.  

What is cement and what is it used for? 

Cement itself is a binding material, predominantly used in construction. The fine grey powder when used with water, it forms a hardened paste that binds other materials together. When cement is mixed with water, sand and gravel, it creates concrete. 

Cement is only one part of the mix used to make concrete, as on its own cement is too brittle and weak for most building applications. 

What is cement made of? 

Cement is typically made up of: 

• Limestone (calcium carbonate). 

• Clay or Shale (provides silica, alumina, and iron). 

• Heated in a kiln to form clinker which is then ground into a fine powder and mixed with gypsum. 

Shale: shale itself is a fine-grained sedimentary rock formed from the compaction and cementation of mud or clay. 

Silica: silica is a natural compound made of silicon and oxygen.  

Clinker: Clinker is a nodular material produced during cement manufacturing, specifically at the pyroprocessing stage. It is a key ingredient in cement, formed by heating limestone and other materials at high temperatures. When ground and combined with gypsum, clinker becomes Ordinary Portland Cement, the primary component of concrete. 

Gypsum: gypsum is a soft sulphate mineral and is composed of calcium, sulphur, oxygen, and water. 

The materials used in cement are crushed and heated to around 1500°C with the resulting byproduct being clinker and is then ground into fine powder ready to be activated with water. 

When water is brought into contact with the cement the chemical reaction called hydration occurs enabling the mixture to harden and provides it the ability to bond with sand, gravel, and other aggregates.  

Cement is not only used in concrete; it is also used in mortar for plastering and grout for masonry. However, cement is a bonding agent and is never used on its own. Cement is also used for foundations as it is crucial for creating strong foundations for buildings and other structures.  

Cement can be categorised into two types: hydraulic and non-hydraulic based on the way it settles and hardens.  

Hydraulic Cement: hydraulic cement reacts with water to form a hardened and water-resistant product, with the water initiating the reaction making the fine powder become a hardened paste. This type of cement has elements including limestone, clay, and gypsum.

Non-Hydraulic Cement: this type of cement does not require water to harden as it will not set in wet conditions, instead, all it needs are dry conditions and the presence of carbon dioxide (CO₂) to set and curate. This type of cement has components containing lime, gypsum, and oxychlorides. 

We now know what cement is, how it is made, the different types of cement, and how it is used but what about concrete? 

What is concrete and what is it used for? 

Concrete itself is a robust, structural material due to its strength and composition. It also has huge advantages like durability to heat and fire protection and can be used to meets the needs of the most challenging construction project.  

Unlike other construction materials, concrete does not need to be heated or shaped in molds at high temperatures. Its flexibility, durability, and affordability make it a preferred choice across every construction sector. 

Concrete in essence is a strong, durable material being composed of various materials (including cement), concrete is made from basic components; water, gravel (coarse aggregate) sand (fine aggregate) and cement. Once combined, this mixture undergoes a chemical reaction called hydration, where the cement (the binding agent) reacts with water and begins to harden and cure. The strength and quality of the concrete can be fundamentally changed by changing the ratios and quantities of aggregates.  

Over time, it forms a rock-like material that gains strength and durability  this is what we call concrete. While people often confuse cement with concrete, they are not the same.  

Cement is just one ingredient in the concrete mix. If you think of concrete like a cake, then cement is the flour. It is essential, but not the final product on its own. 

Fine aggregate is a type of aggregate with particles that are small and are typically less than 4.75mm in diameter. With it primarily being composed of sand or crushed stone, whilst also having the ability to have other fine materials like silt and clay. 

The purpose of fine aggregate is there to fill the spaces between coarse aggregates and help create a dense, compact, and workable mix. It helps reduce voids and increases strength and durability.  

Coarse aggregate on the other hand is particles larger than 4.75mm and ranges up to 50mm. However, this can be further increased for larger structural applications. This type of material is normally gravel and crushed stone and is used to strengthen whilst also adding volume to concrete and other composite materials.  

 Coarse aggregate forms the skeleton of the concrete mix and provides:  

• Bulk and strength 

• Dimensional stability 

• Resistance to shrinkage and cracking 

Both coarse and fine aggregate come together to create a solid, durable mass once the mixture sets and cures.  

Another material that often gets confused with concrete and cement is mortar. Mortar is not dissimilar to the other two but is thicker due to the components used.  

Mortar itself is a paste used to bond building materials like bricks, stones, or other masonry units together and plays a crucial role in masonry construction by creating a strong, durable, and weather-resistant seal between units.  

Most commonly mortar consists of cement (or lime), sand (fine aggregate) and water. The cement acts as the binder, the sand provides volume, and the water activates the binder and makes the mix workable. 

Why do we use cement? 

Cement is an essential material in the construction industry, playing a foundational role in every structure we build today. As the key binding ingredient in both concrete and mortar, cement enables the creation of strong, durable, and versatile building materials that form the backbone of modern infrastructure. From residential homes to highways, bridges, dams, and skyscrapers, cement is fundamental to how we build our world. 

At its core, cement is used because of its unique ability to bind other materials together. Cement is also the primary ingredient in mortar, which is used to bond bricks, stones, and blocks together in masonry construction. This versatility allows cement to serve multiple purposes from laying bricks and rendering walls to constructing massive industrial and civil engineering projects. 

One of the key reasons cements is so widely used is its high compressive strength. It can support heavy loads and withstand environmental pressures such as rain, wind, and fire. It is also adaptable: different types of cement can be formulated to suit specific conditions, such as sulfate-resistant cement, quick-setting cement, and low-heat cement for large pours. 

Cement is also relatively affordable and accessible. Its primary raw materials limestone, clay, and gypsum are abundant in many regions around the world. This makes it cost-effective and suitable for use in both small-scale residential construction and large-scale infrastructure projects. 

In recent years, the cement industry has also taken significant steps toward sustainability. Many producers now incorporate industrial byproducts like fly ash and slag into cement blends, reducing reliance on virgin materials. Research into carbon capture technologies and alternative fuels is also helping to lower the carbon footprint of cement production. 

In summary, we use cement because it provides the strength, versatility, and reliability required in construction, while being cost-effective and increasingly sustainable. Its irreplaceable role as a binder makes it the cornerstone of every modern building material and construction technique in use today. 

Why do we use concrete? 

One of the primary reasons for concrete’s popularity is its exceptional compressive strength. It can withstand heavy loads and harsh weather conditions, making it ideal for long-lasting structures. Once set, concrete becomes a rock-like material that resists fire, water, and pests. Its longevity reduces the need for frequent maintenance, resulting in lower lifecycle costs over time. 

Concrete is also incredibly versatile. In its wet form, it can be poured or molded into any shape. This allows architects and engineers to design both functional and artistic structures. It is compatible with steel reinforcement, creating reinforced concrete that can handle both compression and tension. This flexibility supports a wide range of applications from small patios to massive highways and high-rise buildings. 

Economically, concrete is attractive because it is made from abundant and affordable materials like cement, sand, gravel, and water. In addition, modern concrete can incorporate recycled or alternative materials such as fly ash, slag, or even carbon-capturing additives, making it more sustainable. 

Concrete also contributes to energy efficiency. Its thermal mass helps regulate building temperatures, reducing the need for heating and cooling. New innovations like self-healing concrete and 3D-printed structures continue to expand its possibilities. 

In summary, concrete’s unmatched combination of strength, adaptability, affordability, and sustainability makes it essential to construction and infrastructure. As technology continues to evolve, concrete remains at the core of how we build and shape the modern world. 

Concrete is much more than just a building block, it is a science-driven, highly adaptable material that underpins the world around us. Its formulation can be tailored to meet a broad range of structural and environmental requirements, from skyscrapers to sidewalks, dams to decorative patios. 

Understanding how concrete is made, where it is used, and the types available helps in selecting the right kind for any project, ensuring durability, safety, and efficiency for years to come. 

Need Help With Your Concrete Supply?

Rock Solid Concrete Has You Covered

If you’re still unsure whether you need concrete, what mix to choose, or how much to order we’re here to help. At Rock Solid Concrete, we supply high-quality ready-mixed concrete for all types of residential, commercial, and industrial projects across the UK.

With fast delivery, expert advice, and unbeatable service, we make sure your job stays on schedule and your concrete sets rock solid.

Need a quote or advice? Get in touch today or check out our concrete calculator so we can help you pour with confidence.