IS 5525:1969 is the Indian Standard (BIS) for railway track ballast. This standard specifies the requirements for railway track ballast, covering material types (crushed stone, gravel), physical properties like strength and durability, and size grading for different track gauges. It provides acceptance criteria for ballast used under concrete, steel, and wooden sleepers.
Specifies requirements for material, gradation, and quality of railway track ballast.
| Parameter | IS Value | International | Source |
|---|---|---|---|
| Los Angeles Abrasion Value (Max % loss) | ≤ 30% (for Broad Gauge) | Typically ≤ 25% for high-speed/heavy haul lines; up to 40% for low density lines. | AREMA Manual Ch. 1, Pt. 2 |
| Water Absorption (Max %) | ≤ 1.0% | ≤ 1.0% (can be ≤ 0.5% for high-quality ballast) | AREMA Manual Ch. 1, Pt. 2 |
| Flakiness & Elongation Index (Combined) | ≤ 25% | Not directly comparable. EN 13450 uses separate Flakiness Index (FI ≤ 20) and Shape Index (SI ≤ 20) categories. | EN 13450:2002 |
| Fines Passing 75-micron / No. 200 sieve (Max %) | ≤ 1.0% | ≤ 1.0% by mass | AREMA Manual Ch. 1, Pt. 2 & EN 13450 |
| Soundness (Magnesium Sulfate, 5 cycles, Max % loss) | ≤ 10% | ≤ 10% (can be specified as low as ≤ 5% for severe weather conditions) | AREMA Manual Ch. 1, Pt. 2 |
| Nominal Grading (Mainline) | 65mm or 50mm | 31.5/50 mm or 31.5/63 mm (d/D) | EN 13450:2002 |