InfraThread® Geotextile Class Guide: InfraThread® vs Bidim® Equivalents
Introduction
Infrastructure projects across Australia and New Zealand demand geotextiles that meet strict specification requirements. The InfraThread® PET Nonwoven Geotextile series is engineered to comply with:
• MRTS27 (Queensland Department of Transport and Main Roads)
• R63 (Transport for NSW)
• TNZ F/7 (Waka Kotahi NZ Transport Agency)
• Section 712 (VicRoads)
This guide explains how each InfraThread® class aligns with common Bidim® strength classes (A14 to A49) and where they are typically used — from subsoil drains to landfill capping.
Understanding Classification
Older versions of MRTS27, R63, and TNZ F/7 specified separate “filtration” and “strength” classes for geotextiles.
Current practice now selects products primarily by strength class (A–E) based on subgrade strength and aggregate size, while filtration performance is simply confirmed via test values.
All InfraThread® PET nonwoven grades exceed the minimum filtration criteria (AOS ≤ 120 µm, flow ≥ 50 L/m²/s), so separate filtration class selection is no longer required.
InfraThread® Class Equivalency Overview
To make specification easier, here’s how our InfraThread® PET nonwoven geotextile series aligns with the commonly used Bidim® A-Class strength ratings. This shows the equivalent strength class (A–E) and the typical applications each grade is suited for.
|
InfraThread® Class |
Closest Bidim® Grade |
Strength Class |
Typical Applications |
|
150NW |
A14 |
Class A |
Landscaping fabric, garden drains, wrapping small perforated pipes |
|
200NW |
A19 |
Class B |
Road shoulder drains, subsoil trench lining, shallow retaining wall drainage |
|
300NW |
A29 |
Class C |
Pavement subgrade separation, railway formation drainage, general roadworks |
|
400NW |
A39 |
Class D |
Heavy civil works, embankments over soft soils, crane pads, wind farms |
|
450NW |
A44 |
Class E |
Landfill capping, mining haul roads, causeways, rock mattress/revetments |
|
500NW |
A49 |
Class E |
Landfill capping, mining haul roads, causeways, rock mattress/revetments |
⚠️ Disclaimer: This table provides general guidance only.
Final geotextile selection must consider site-specific conditions (subgrade strength, aggregate size, and construction method) in accordance with MRTS27 (QLD), R63 (NSW), and TNZ F/7 (NZ).
Sample Applications
☑ 150NW – Class A
• Use: Landscaping, garden beds, lightweight separation
• Example: Retaining wall backfill drainage for residential construction
☑ 200NW – Class B
• Use: General subsoil drains, verge trenches
• Example: Rural road shoulder reconstruction in Northern NSW
☑ 300NW – Class C
• Use: Pavement separation, soft subgrade support
• Example: Railway drainage layer – Ballarat Line Upgrade (VIC)
☑ 400NW – Class D
• Use: Reinforced embankments, wind farm access roads
• Example: Transmission line subgrade stabilisation – QLD
☑ 450NW / 500NW – Class E
• Use: High-load zones, landfill, mining haul roads
• Example: Landfill capping layer – Hunter Region, NSW
Conclusion
The InfraThread® PET nonwoven range offers engineers and contractors a dependable, standards-aligned geotextile solution for everything from minor landscaping to major civil infrastructure. With direct equivalence to Bidim® A-class grades and full compatibility with MRTS27, R63, TNZ F/7, and VicRoads specs — InfraThread® delivers confidence across projects of every scale.
