GRC / Alkali-Resistant Glass Fiber
High-Zirconia AR Glass | Glass Reinforced Concrete | Long-Term Durability
GRC / AR Glass Fiber
Our alkali-resistant (AR) glass fibers contain a minimum of 16% zirconia (ZrO₂) by weight, which provides outstanding resistance to the highly alkaline environment of Portland cement hydration (pH 12–13.5). While conventional E-glass fibers suffer rapid strength degradation in cement matrices, AR-glass maintains the majority of its original strength and toughness over decades of service life. Available as continuous roving for GRC spray processes and as chopped strands for premix and concrete casting applications.
Key Features
- High zirconia content (≥16% ZrO₂) for alkali resistance
- Suitable for spray-up, premix and CNC GRC processes
- Long-term retention of tensile strength and impact toughness
- Compatible with OPC, SRPC, white cement and polymer-modified mortars
- Lightweight alternative to steel reinforcement for thin sections
- Low thermal expansion — reduces cracking in temperature cycling
- Available as roving (for spray) and chopped strands (for premix)
Why Alkali-Resistant Glass?
Portland cement produces calcium hydroxide (Ca(OH)₂) during hydration, creating a strongly alkaline pore solution with a pH above 12. Standard E-glass and A-glass fibres dissolve rapidly in this environment: silica at the filament surface is attacked, the interfilament bonds break down, and within months the reinforcement can lose over 50% of its original strength. This makes conventional fiberglass completely unsuitable as a concrete reinforcement in the long term.
Alkali-resistant glass overcomes this problem by incorporating zirconia (ZrO₂) into the glass composition. ZrO₂ forms a protective layer around the silicate network that is stable at high pH, dramatically slowing corrosion rates. Glass Reinforced Concrete (GRC/GFRC) products using AR-glass fiber have demonstrated excellent durability over 40+ years of field exposure, meeting the requirements of GRCA International norms and EN 14649 accelerated ageing tests.
GRC panels are 70–80% lighter than equivalent solid concrete, enabling use of thinner sections (12–18 mm typical), reducing structural load and opening up completely new design possibilities for architects working with complex curved, textured and patterned concrete surfaces.
Note: We supply multiple grades and qualities to match your application — share your requirements and we will recommend the right product.