Aggregate Crushing Value (ACV) Test: Equipment and Procedure

What Is the ACV Test?

The Aggregate Crushing Value test quantifies the resistance of aggregate to crushing under a gradually applied compressive load. The result — expressed as a percentage of fines passing a 2.36 mm sieve relative to the original mass — indicates whether an aggregate is suitable for road base, surface course, or structural concrete.

The test is standardized under BS 812-110 and referenced in many national road specifications. A lower ACV indicates stronger aggregate.

Equipment Required

• ACV Cylinder & Plunger: 150 mm diameter steel cylinder with plunger that fits inside. Must be hardened and ground.
• Compression Testing Machine: Capable of applying 400 kN at a uniform rate over 10 minutes.
• Sieves: 14 mm, 10 mm (for specimen preparation) and 2.36 mm (for result measurement).
• Tamping Rod: 16 mm diameter, rounded end, 600 mm length.
• Balance: Accurate to 0.1 g.

Test Procedure (BS 812-110)

1. Sieve aggregate to retain on 10 mm and passing 14 mm. Oven-dry at 105°C to constant mass.
2. Fill the cylinder in three layers, tamping each layer 25 times with the tamping rod.
3. Level the surface and record mass of aggregate in cylinder (M₁).
4. Place plunger carefully and load in the compression machine. Apply 400 kN over exactly 10 minutes.
5. Remove the crushed aggregate and sieve over 2.36 mm. Record mass passing (M₂).
6. Calculate: ACV (%) = (M₂ / M₁) × 100

ACV Acceptance Criteria