Boral Blue Circle General Purpose Lime

Boral Blue Circle General Purpose Lime is a high-purity, finely milled hydrated lime (calcium hydroxide) designed for a variety of building and construction needs. Conforming to Australian Standard AS 1672.1 for building limes, this product improves the workability, water retention, and binding qualities of cement-based mortars and renders, making it essential for achieving durable and flexible finishes. Its high reactivity and low residue ensure consistent performance in both residential and commercial projects.

Key features include exceptional purity for enhanced chemical reactivity, fine particle size for better mixing and settling, and versatility in applications where added plasticity is required. It is not hydraulic on its own and must be used in conjunction with Portland cement for mortars and renders. Available in convenient 20kg multi-walled paper sacks, it suits DIY and professional uses from plastering to soil amendment.

Technical specifications highlight its superior quality:

• Available Lime Index (as Ca(OH)2): >90%.
• Chemical Composition: Calcium Oxide (CaO) 72.5%, Magnesium Oxide (MgO) 0.7%, Aluminium Oxide (Al2O3) 0.5%, Silicon Dioxide (SiO2) 1.1%, Loss on Ignition 24-25%.
• Fineness: Residue on 75μm sieve >3.5%.
• Specific Gravity: 2.0-2.2.
• Bulk Density: 450-500 kg/m³.
• Solubility: 1.65 g/L at 20°C.

For optimal results, follow recommended mix designs:

• General mortar (M3): 1 part cement, 1 part hydrated lime, 6 parts sand.
• Severe exposure mortar (M4): 1 part cement, 0.5 parts hydrated lime, 4.5 parts sand.
• General rendering: 1 part cement, 0.5 parts hydrated lime, 4 parts sand.
• Add approximately 1 part lime per 5-6 parts sand in cement mixes to improve workability without plasticisers.

Store in a cool, dry, watertight environment off the ground to prevent moisture absorption and product deterioration—dispose of products older than 12 months or if exposed to damp conditions. Safety precautions are essential: Avoid generating dust and inhalation with P2 masks in well-ventilated areas; use goggles, gloves, and barrier creams; wash off skin contact immediately to prevent irritation or burns. Causes skin irritation, serious eye damage, and respiratory irritation; contains calcium hydroxide; refer to the Safety Data Sheet for full details.

Choose Boral Blue Circle General Purpose Lime for high-quality, reliable enhancements to your building mixes, backed by Australia’s trusted leader in construction materials.