No-Fines Concrete (NFC) is a lightweight, porous building material made from cement, water, and coarse aggregate, omitting fine aggregates (sand). This structure creates large air voids (15-25%), offering excellent drainage, lower density, and thermal insulation. Commonly used for retaining walls, stormwater management, and sustainable drainage systems, it thrives where high permeability and low shrinkage are required.

Key Characteristics:

• High Permeability: Allows water to flow through freely, reducing hydrostatic pressure behind structures.
• Reduced Density/Weight: Lower weight reduces structural loads on foundations.
• Low Shrinkage: Reduced risk of cracking compared to conventional concrete.
• Cost-Effective: Often allows for faster construction and reduced material costs.
• Sustainability: Reduces stormwater runoff and aids in groundwater recharge.

Key Applications:

• Retaining Walls: Used extensively as permeable backfill in segmental retaining walls to prevent water buildup and improve structural stability.
• Paving and Pavement Sub-bases: Ideal for permeable car parks, footpaths, and driveways, managing stormwater on-site.
• Drainage Structures: Used in civil engineering projects for drainage channels and subsurface drainage.
• Building Construction: Utilized in walls for light-weight structural performance, providing insulation benefits.

Components and Technical Specifications

• Aggregate Size: Typically uses 19-20mm aggregate for optimum void formation.
• Mix Ratio: Generally a ratio of 8:1 to 10:1 (aggregate:cement) by mass, or 6:1 (gravel:cement).
• Installation: Cannot be pumped, and is best placed by direct chute or skip. 

Key Limitations

• Low Strength: Lower compressive strength compared to traditional concrete, restricting its use to lighter loads.
• Clogging: Requires protection (geotextile fabrics) to prevent fines from clogging voids and reducing permeability