Fly ash is a coal combustion product used in construction, infrastructure and environmental applications across South Africa. It improves material performance, reduces environmental impact and supports more sustainable use of industrial resources.
South Africa produces over 50 million tonnes of ash annually, yet utilisation remains relatively low compared to global benchmarks.
Increasing the use of fly ash presents a clear opportunity to:
SACAA works with industry, regulators and stakeholders to support the responsible use, technical understanding and broader adoption of fly ash across South Africa.
Fly ash is a fine powder produced during the combustion of coal in power stations. It is captured from flue gases and processed for use in a range of construction and industrial applications.
In South Africa, fly ash is predominantly siliceous (pozzolanic), making it particularly suitable for use in cement and concrete. Fly ash forms part of a broader group of materials known as coal combustion products (CCPs).
Fly ash is produced in different forms depending on collection methods, processing and intended application. These materials form part of the broader coal combustion product (CCP) category used across industry.
These materials vary in composition and application, depending on their processing and end-use requirements.
Fly ash used in South Africa is required to meet SANS 50450‑1, the national standard that ensures consistent quality and performance. When conforming to this specification, fly ash delivers the following benefits in concrete:
• Increased long-term strength development
• Reduced permeability and chloride penetration
• Mitigation of alkali-silica reaction
• Lower heat of hydration
• Reduced shrinkage
• Improved workability
• Enhanced sulphate resistance
The use of fly ash contributes to more sustainable construction and material use:
• Reduces reliance on cement, lowering CO₂ emissions
• Minimises waste sent to ash disposal facilities
• Supports the reuse of industrial by-products
• Contributes to more efficient use of natural resources
Fly ash is used across a range of construction, infrastructure and environmental applications. Its versatility allows it to be applied in both structural materials and large-scale industrial processes.
The range of applications continues to expand as industry develops new methods for the responsible use of fly ash across different sectors.
Fly ash forms part of a broader technical and regulatory landscape. The following resources provide additional context, standards and research related to its use in South Africa.
SACAA supports informed decision-making through access to technical guidance, regulatory frameworks and industry research.
