Cement vs concrete vs mortar: choosing the right material for the job

Choosing suitable construction materials is crucial. Optimal material selection balances cost-effectiveness, safety, compliance, sustainability, functionality, and availability. By carefully considering these factors, construction professionals can improve efficiency, and longevity.

Cement
Cement is a binding agent for concrete and mortar. Typically produced as a fine powder from materials like limestone, clay, shells, and silica sand, cement undergoes high-temperature heating to form a clinker before finely ground.

Advantages of cement

• Binding properties: one of the primary strengths of cement is its ability to bind together. Cement undergoes a chemical reaction known as hydration when mixed with water, forming a hardened mass.

• Strength development: as hydration progresses, cementitious compounds, such as calcium silicate hydrate (c-s-h) gel and calcium hydroxide, form within the cement paste matrix, resulting in increased strength and stiffness of the hardened concrete or mortar.

• Durability: cement-based materials possess inherent durability characteristics that resist various environmental factors, including weathering, abrasion, chemical attack, and biological degradation. Adequately designed and cured cementitious structures can maintain their integrity and functionality over extended periods, even in harsh conditions.

• Fire resistance: cement-based materials offer considerable fire resistance due to their non-combustible nature and ability to withstand high temperatures without significant degradation. This property makes cement ideal for fireproofing structural elements, such as columns, beams, and walls, enhancing the safety and fire protection of buildings and infrastructure.

• Adaptability to design requirements: cementitious materials can be tailored to meet specific design requirements and performance criteria through adjustments in mix proportions, additives, and curing methods. This adaptability allows engineers and architects to optimise the properties of concrete or mortar to suit the intended application, whether it involves achieving high strength.

Concrete
Concrete is a composite material widely used in construction, consisting primarily of four key components: cement, aggregates, water, and additives. Aggregates, including sand, gravel, and crushed stone, provide bulk and strength to the concrete mix. Water is essential for the hydration process of cement, facilitating a chemical reaction.

Advantages of concrete

• Compressive strength: concrete has excellent compressive strength, meaning it can withstand significant weight or pressure without collapsing or deforming.

• Durability: concrete is highly durable and can withstand harsh weather conditions, chemical exposure, and wear and tear over time. This makes it suitable for various outdoor and indoor applications.

• Fire resistance: concrete is inherently fire-resistant, providing an added layer of safety in buildings and structures.
  

• Versatility: concrete can be moulded into various shapes and forms, allowing for flexibility in design and construction.
  

• Low maintenance: once correctly installed, concrete requires minimal maintenance compared to other construction materials, reducing long-term costs.
  

• Thermal mass: concrete has a high thermal mass, meaning it can absorb and store heat, helping to regulate indoor temperatures and reduce energy consumption.
  

Mortar
Composed of cement, water, sand, and sometimes lime, mortar unites bricks, stones, or concrete blocks, ensuring structural integrity and stability in buildings and other structures. Its primary function is filling gaps between masonry units, creating a cohesive bond that withstands the test of time and environmental pressures.

• Strength and durability: mortar provides strong and durable bonds between masonry units, ensuring the structural integrity and longevity of the building.

• Weather resistance: mortar protects masonry from the effects of weathering, such as moisture penetration, freeze-thaw cycles, and thermal expansion, enhancing the longevity of the structure.

• Versatility: mortar can be tailored to meet specific project requirements, with different types available to accommodate various applications and performance criteria.

• Ease of application: mortar is relatively easy to mix, apply, and shape, allowing for efficient installation and construction processes.
  

How do you choose a cement mix?

Here are some key considerations to help you choose the appropriate cement mix:

• Strength requirements:
  Determine the strength requirements of your project. Different types of cement mixes offer varying strength levels, typically designated by a numerical classification such as 2500, 3000, 3500, etc., indicating the pounds per square inch (psi) of compressive strength.
  

• Environmental conditions:
  Consider the environmental conditions your project will be exposed to, such as extreme temperatures, freeze-thaw cycles, or exposure to chemicals. Certain cement mixes may be more suitable for specific environmental conditions.

• Aggregate size and type:
  Consider the size and type of aggregates used in your concrete mix. The proportions of cement, water, and aggregates (sand, gravel, or crushed stone) will vary based on the desired properties of the concrete.
  

• Special requirements:
  If your project has specific requirements such as rapid setting, high durability, sulphate resistance, or low shrinkage, you may need a specialised cement mix or additives to achieve those properties.
  
  

Differences between cement, concrete and mortar

Cement

• Cement is a binding agent used in construction.

• It's a fine powder, usually grey or white.
  They are mainly composed of limestone, clay, and gypsum.

• It's mixed with water to form a paste that hardens over time, binding materials like sand and aggregating.

• Used in making concrete and mortar.
  

Concrete

• Concrete is a composite material made of cement, water, aggregates (like sand and gravel), and often additives.

• It's a versatile construction material for foundations, slabs, driveways, and more.
  Concrete gains strength as it cures and hardens.

• It's durable, strong, and can be formed into different shapes.
  

Mortar

• Mortar is a mixture of cement, sand, and water.

• It's used as a bonding agent between bricks, stones, or concrete blocks in masonry construction.

• Mortar holds the masonry units together and provides strength and durability to the structure.

• It's available in various types, such as cement mortar, lime mortar, and others, each suited for different applications and conditions.
  

Concrete and mortar are two commonly used materials in construction, and understanding their differences can be confusing. Concrete is a robust and durable material, perfect for structural applications such as foundations, slabs, and walls. Conversely, Mortar is ideal for binding smaller masonry units together, like bricks or stone walls.