📌 PURPOSE: Engineering reference data for RPEQ site‑specific design. Not a Form 15. All final certification by project engineer.
Applicable standards
Australian Standards
AS 1170.0, 1170.1, 1170.2, 1170.4
AS 4678, AS 2870, AS 3600, AS 4100, AS/NZS 3679
AS 4678, AS 2870, AS 3600, AS 4100, AS/NZS 3679
Document status
v4.1 (Mar 2026) current – supersedes all earlier versions
FRP material properties
Mechanical
| Tensile strength | 150 MPa |
| Flexural strength | 180 MPa |
| Elastic modulus E | 20 GPa |
| Shear strength | 25 MPa |
Durability
- corrosion / termite / rot resistant
- UV stabilised
- design life ≥50 years
FRP sleeper section
Dimensions
200×60 mm hollow
Wall thickness: 2.5 mm
Lengths: 1.6 m, 2.0 m, 2.4 m
Wall thickness: 2.5 mm
Lengths: 1.6 m, 2.0 m, 2.4 m
Section properties
Ixx 4.0×10⁶ mm⁴
Zxx 4.0×10⁴ mm³
Iyy 1.08×10⁶ mm⁴
Zyy 3.6×10⁴ mm³
Zxx 4.0×10⁴ mm³
Iyy 1.08×10⁶ mm⁴
Zyy 3.6×10⁴ mm³
Bending capacity
Ultimate moment Mu = 7.2 kNm
Design moment Md = 4.8 kNm
Design moment Md = 4.8 kNm
Shear capacity
≈ 15 kN per sleeper
(not critical for spans ≤2.4 m)
(not critical for spans ≤2.4 m)
System weight (per 2m bay)
Concrete
450–500 kg
Ezzy Fit FRP
50–60 kg
85–90% lighter
FRP posts
| Section | Ixx (mm⁴) | Zxx (mm³) | Max height |
|---|---|---|---|
| 100×100×6 H/U | 2.4×10⁶ | 4.8×10⁴ | 1.0 m |
| 100×100×10 H/U | 4.0×10⁶ | 8.0×10⁴ | 2.0 m |
⛔ Walls over 2.0 m require steel posts.
Steel posts (>2.0 m walls)
| Wall height | Minimum steel post |
|---|---|
| 2.0 – 3.0 m | 100×100×4 SHS or 150UC |
| 3.0 – 5.0 m | 150×150×5 SHS or 200UC/UB |
Post embedment
| Wall height | Embedment depth |
|---|---|
| 1.0 m | 1.0 m |
| 2.0 m | 2.0 m |
| 3.0 m (steel) | 3.0 m |
| 4.0–5.0 m (steel) | 3.5 m |
Post footing
Pier diameter: 450 mm · Concrete: 25 MPa · Cover: 50 mm
Sleeper load capacities
Working loads (kN/m)
| 1.6 m span | 2.3 |
| 2.0 m span | 1.8 |
| 2.4 m span | 1.5 |
Ultimate loads (kN/m)
| 1.6 m span | 4.0 |
| 2.0 m span | 3.15 |
| 2.4 m span | 2.6 |
Deflection
2.0 m span @ 4.7 kN → 10–15 mm
Serviceability limit L/180 = 11.1 mm
Serviceability limit L/180 = 11.1 mm
Wall batter
1:40 forward lean (40 mm per metre height)
Post spacing (5 kPa surcharge)
| Wall height | Post type | Max spacing |
|---|---|---|
| ≤1.0 m | FRP 100×100×6 | 2.4 m |
| 1.0–2.0 m | FRP 100×100×10 | 2.0 m |
| 2.0–3.0 m | steel posts | 1.6 m |
| 3.0–5.0 m | steel UC/UB | engineered design |
Drainage
All walls: 20 mm gravel, geofabric, 100 mm base drain, fall 1:100
Walls ≥1.6 m: secondary drainage at second‑top sleeper
Installation sequence
1. Install posts & footings
2. Install sleepers
3. Drainage & backfill
Engineer review
RPEQ name ____________________
Signature ____________________
RPEQ number __________________
Date _________________________