Silica White — Volcanic Glass Micro-Powder Concrete Admixture

Problem solved

Reducing the clinker factor in concrete without sacrificing strength or durability is the primary lever for cutting construction embodied carbon, but supplementary cementitious materials (fly ash, slag, silica fume) face supply constraints and regional availability limits. Silica White offers a natural-pozzolan alternative sourced from domestic volcanic deposits.

Application contexts

• Marine / coastal infrastructure requiring chloride penetration resistance
• Water-retention structures (tanks, reservoirs, sewage facilities)
• Freeze-thaw exposed infrastructure (roads, bridges in cold regions)
• High-durability precast concrete products

Technical principle

Volcanic glass (SiO₂-rich amorphous phase) is dried and pulverized to specific surface area ~5,000–8,000 cm²/g (3–4× cement fineness). When added to concrete, the amorphous silica dissolves in the alkaline pore solution and reacts with portlandite (Ca(OH)₂) from cement hydration to form secondary C-S-H gel, densifying the interfacial transition zone and reducing capillary porosity. This improves impermeability, chemical resistance, and freeze-thaw durability while enabling 10–20% cement replacement depending on target performance.

Typical use cases

• Replace 10–15% of OPC in ready-mix concrete for bridge substructures in coastal environments
• Admixture in precast sewer / water pipes to improve acid resistance and reduce cement dosage
• Enhancement additive for concrete exposed to de-icing salts (road infrastructure in cold regions)