Metakaolin, white

Metakaolin – High Reactivity Pozzolan for High Performance Concrete

Metakaolin is an ultra-fine, highly reactive pozzolanic mineral admixture used to produce stronger, denser, and more durable concrete. Manufactured from carefully calcined high-purity kaolin clay, metakaolin reacts with calcium hydroxide during cement hydration to create additional cementitious compounds that improve both performance and long-term durability.

Widely used in GFRC, UHPC, precast concrete, architectural concrete, concrete countertops, cast stone, and high-performance cementitious mixes, metakaolin is one of the most effective supplementary cementitious materials available for reducing permeability, increasing strength, and refining concrete surface quality.

Unlike darker pozzolans such as fly ash or silica fume, high-reactivity metakaolin is naturally light in color, making it ideal for white concrete, integral pigments, decorative concrete, and architectural applications where color consistency and brightness matter.

Benefits of Metakaolin in Concrete

• Increases compressive and flexural strength
• Produces denser, less permeable concrete
• Improves durability and chemical resistance
• Reduces efflorescence and surface dusting
• Helps minimize shrinkage and microcracking
• Improves resistance to chloride penetration and freeze/thaw exposure
• Enhances particle packing and surface finish quality
• Reduces the effects of alkali-silica reaction (ASR)
• Improves consistency in GFRC and UHPC mixes
• Excellent for light-colored and white concrete applications

Metakaolin is commonly used in high-performance concrete systems at replacement rates ranging from approximately 5%–15% of total cementitious content, depending on the application and desired performance characteristics.

Ideal Applications

• GFRC (Glass Fiber Reinforced Concrete)
• UHPC & HPC concrete mixes
• Concrete countertops
• Architectural precast concrete
• Concrete sinks and furniture
• Thin concrete wall panels & cladding
• Shotcrete and repair mortars
• Decorative concrete
• White concrete applications
• High-density concrete mixes

Why Use Metakaolin?

As concrete technology continues to advance, metakaolin has become a preferred pozzolan for fabricators and manufacturers looking to maximize performance without sacrificing workability or appearance. The extremely fine particle size helps fill microscopic voids within the concrete matrix while the pozzolanic reaction creates additional calcium silicate hydrate (C-S-H), resulting in stronger and more durable concrete.

For concrete countertop makers, GFRC fabricators, and architectural concrete producers, metakaolin can help create smoother surfaces, tighter finishes, reduced pinholes, improved edge quality, and higher overall performance.

Typical Uses in Mix Design

Metakaolin is often blended with:

• Portland cement
• White cement
• Silica fume
• Pozzolans
• Acrylic polymers
• Superplasticizers
• GFRC and UHPC admixture systems

It can be used in both dry-cast and flowable high-performance concrete mixes.