Sustainable Drainage with No-Fines Concrete

Permeable Concrete (also known as no‑fines concrete, pervious concrete, porous concrete, or permeable paving concrete) is a high‑void concrete mix engineered to improve storm‑water management and reduce surface flooding. With an air‑void content of 15–25 %, this specialised mix allows water to flow directly through its porous structure, preventing runoff and supporting natural groundwater recharge.

Ideal for footpaths, car parks, retaining walls, and tree surrounds, Permeable Concrete offers a sustainable solution for urban infrastructure by minimising stormwater drain dependency while reducing damage caused by root growth.

Key Benefits of Permeable Concrete 

• Superior Water Drainage – The high porosity of permeable concrete allows rainwater and runoff to infiltrate the ground, reducing pressure on storm‑water systems and preventing surface ponding.
• Resistant to Root Damage – Its open structure makes Permeable Concrete less susceptible to cracking and displacement caused by expanding tree roots, extending the lifespan of pavements and landscaped areas. 
• Customisable Strength & Performance – Typical compressive strengths of 10–15 MPa (and up to 20 MPa with optimised mixes) mean the balance between strength and permeability can be tailored to project needs. Not suitable for heavily trafficked applications. 
• Sustainable & Green‑Building Friendly – By enabling natural water absorption, Permeable Concrete supports sustainable construction goals and can contribute to Green Star because of the design benefits in using this type of stormwater management medium.

Placing, Curing & Testing 

• Correct Placement for Optimal Performance – Permeable Concrete is delivered ex truck and requires compaction with a roller or plate compactor to achieve a strong bond between the paste and aggregate. Careful compaction is essential to maintain porosity while ensuring durability.
• Curing to Prevent Drying & Improve Strength – Due to its high surface exposure, Permeable Concrete is susceptible to drying out. Immediate curing is required after compaction, typically by covering with plastic sheeting or applying curing compounds. A minimum curing period of 7 days is recommended to aid strength development.This helps prevent dusting on the surface. 
• Testing for Quality Control – Traditional slump testing is ineffective for Permeable Concrete due to its low workability. Instead, density and void content are key quality indicators. Testing follows the NZS 3111 Section 10 method for determining unit mass and void content of aggregate.Remember subgrade preparation (outside of the concrete) is critical for great outcomes.

Choosing the Right Permeable Concrete Mix