May 27, 2024

Dolomitic Lime: The Unsung Hero of the Construction Industry

Dolomitic Lime: The Unsung Hero of the Construction Industry

Dolomitic lime, a natural mineral compound, primarily composed of calcium and magnesium carbonates, is an indispensable component in the construction industry, contributing to the strength, durability and sustainability of various construction materials and projects. An essential resource for builders and engineers, it presents a wide range of construction applications, including masonry, road construction, soil stabilisation, and as a component in concrete and mortar mixtures. 

Use and importance of dolomitic lime in the construction industry

Concrete production

Dolomitic lime is a key ingredient in the production of concrete, serving as a supplementary cementitious material. As fundamental building material in the construction industry, concrete consists of a mixture of cement, as well as aggregates such as sand and gravel, water, and various other additives. Dolomitic lime can be used to partially replace cement, offering benefits such as reduced shrinkage and improved durability.

When dolomitic lime is incorporated into the mix, it reacts with water and carbon dioxide in a process known as carbonation, forming calcium-magnesium carbonate. The compound helps fill the voids within the concrete, making it denser and more resistant to moisture penetration, ultimately improving the long-term durability of concrete structures.

Soil stabiliser

Mixed with soil, dolomitic lime can enhance the soil's properties, making it more suitable for construction projects. 

Stabilising the soil is a vital step to ensuring the ground can support the weight of structures and roadways while preventing issues like settling or erosion. The addition of dolomitic lime improves the cohesion and load-bearing capacity of the soil, making it an essential component in foundation preparation and road construction.

Mortar production

Mortar is a critical component in masonry construction. Its chief use is to bind bricks or stones together. This presents another use for dolomitic lime which is often added to mortar mixtures to enhance their workability and performance. It improves the adhesive properties of the mortar and reduces cracking, ensuring a more robust bond between masonry units. The addition of dolomitic lime also contributes to the mortar's ability to self-heal, as it can re-seal small cracks that may develop over time.

Road construction

In road construction, dolomitic lime is used in several ways. It can be applied as a base or sub-base material to enhance the strength and stability of the roadbed. When mixed with aggregates and compacted, dolomitic lime can increase the load-bearing capacity of the road, preventing rutting and improving the overall durability of the pavement. Additionally, dolomitic lime is used to modify asphalt mixes, improving their resistance to rutting, cracking, and moisture damage.

Plaster and stucco

Dolomitic lime is a valuable component in the production of plaster and stucco, both used to coat and finish interior and exterior surfaces, providing aesthetic appeal and protection against the elements. The dolomitic lime inclusion improves workability and adhesion to surfaces. It also helps prevent cracking and enhances the overall durability of the finished coatings.

Dolomitic lime to address environmental Issues

Neutralising acidic soils

Beyond primary construction-related uses, dolomitic lime can also be used to neutralise acidic soils, which are detrimental to both plant growth and infrastructure. When spread over acidic soils, dolomitic lime reacts with the acidity, raising the soil's pH and making it more conducive to vegetation and less corrosive to buried infrastructure.


Used in the treatment of wastewater and the removal of impurities from industrial processes, dolomitic lime helps to adjust the pH of wastewater, making it safer for discharge into natural water bodies. In industrial applications, it can be utilised to capture and neutralise pollutants, reducing their harmful impact on the environment.

Fire resistance

Dolomitic lime enhances the fire resistance of construction materials. When included in building products like plaster or concrete, it can significantly improve the materials’ fireproofing properties, a quality that is particularly important in commercial and industrial construction, where fire safety standards are stringent.

Energy efficiency

Use in concrete and mortar mixtures means that the insulation properties of the materials can be improved, reducing energy consumption for heating and cooling. Additionally, it can also be incorporated into “green” building materials, to minimise environmental impact and reduce energy consumption in construction.

Aesthetic appeal

In architectural and decorative applications, dolomitic lime can be used to create elegant, smooth finishes on walls and ceilings, offering a timeless appearance. The natural white or light grey colour of dolomitic lime can also be tinted or pigmented to achieve a wide range of decorative effects, making it a popular choice for interior and exterior design.

Bringing health back to Southern African soil

Lime Sales Ltd. is one of the leading producers and suppliers of dolomitic limestone products in the Western Cape. We supply dolomite, calcite and gypsum to the agricultural, construction and civil construction industries.


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