What are the main tests for railway ballast quality?

The key tests are the Aggregate Abrasion Test (Los Angeles Test), Aggregate Impact Test, and Water Absorption Test (Clause 4 & Table 1).

What is the maximum permissible abrasion value for ballast under concrete sleepers?

The maximum Los Angeles Abrasion value is 30% for ballast used with concrete or steel sleepers (Table 1).

What is the specified size range for ballast on a Broad Gauge (BG) track?

For BG tracks, the ballast should be graded such that 100% passes the 80 mm sieve and no more than 5% passes the 40 mm sieve (Table 2).

IS 5525

: 1969

Railway Track Ballast

CurrentSpecializedSpecificationTransportation · Railway Engineering

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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.

Quick Reference Values

Maximum Aggregate Abrasion Value (for concrete/steel sleepers)30%

Maximum Aggregate Impact Value (for concrete/steel sleepers)20%

Maximum Water Absorption1.0%

Percentage passing 80 mm IS Sieve (Broad Gauge)100%

Percentage passing 40 mm IS Sieve (Broad Gauge)0 to 5 %

Practical Notes

This is an old and superseded version. Always refer to the latest revision (IS 5525:2022) for current projects, as requirements and test methods have been updated significantly.

Ballast quality is paramount for track stability and drainage. Source selection and regular testing as per the code are critical.

Pay close attention to the size and grading requirements (Table 2) as they differ for Broad Gauge (BG), Metre Gauge (MG), and Narrow Gauge (NG) tracks.