The Aggregate Crushing Value Apparatus is a laboratory device used to determine the strength of coarse aggregates under gradually applied compressive load. The aggregate crushing value (ACV) test gives an indication of the aggregate s resistance to crushing under a gradually applied load, which is important for evaluating durability and suitability in road and pavement construction.
Components
Compression Testing Machine or Load Application Mechanism
Provides a gradually applied compressive load.
Load capacity usually up to 400 500 kN for aggregate testing.
Cylinder / Mould
A metal cylinder with internal diameter of 75 mm and height of 150 mm.
The cylinder holds the aggregate specimen for testing.
Plunger / Loading Plate
A flat circular steel plunger that applies uniform load to the aggregate.
Metal Base Plate
Supports the cylinder and ensures even load distribution.
Sieve (2.36 mm)
After testing, crushed aggregates are sieved to measure the finer fraction.
Weight Balance
Measures the weight of aggregates passing the sieve and the total weight for calculating ACV.
Working Principle
Aggregate of a specified size (typically 10 20 mm) is placed in the cylinder.
The plunger applies a gradually increasing compressive load at a uniform rate.
Load is applied until one-third of the cylinder height is crushed.
The crushed aggregate is removed and sieved through a 2.36 mm sieve.
The aggregate crushing value (ACV) is calculated as:
ACV(%)=Weight of fines passing 2.36 mm sieveTotal weight of sample 100ACV (\%) = \frac{\text{Weight of fines passing 2.36 mm sieve}}{\text{Total weight of sample}} \times 100ACV(%)=Total weight of sampleWeight of fines passing 2.36 mm sieve 100
Lower ACV indicates stronger aggregates.
Higher ACV indicates weaker aggregates, more prone to crushing.
Applications
Evaluating strength and quality of coarse aggregates for road construction.
Selecting suitable aggregates for pavement, concrete, and other structural work.
Assessing aggregate durability and mechanical stability.
Advantages
Simple and reliable method to classify aggregates by crushing strength.
Provides a quantitative measure of aggregate quality.
Limitations
Not suitable for very soft aggregates; may overestimate weakness.
Requires careful sample preparation to ensure consistent results.