Test Name: Methods for determination of Aggregate Crushing Value (ACV)
Code: BS 812 Part 110, IS 2386
Definition of ACV: Aggregate Crushing Value (ACV) gives an relative measure how the aggregate act under an gradually acting compressive load.
Sieve Size: ACV is applicable for aggregates passing 14.0 mm sieve and retained on 10.00 mm sieve. For other size fractions methods are described in th respective codes.
Sampling of Aggregate: The sampling of aggregate for ACV have to comply with the sampling procedure described in BS 812 Part 102:1989
All aparatus have to comply with the BS code requirements of BS 812 Part 110
- A steel Cylinder with internal dia of 150 mm with a plunger and baseplate. Must have to a hardness value of 650 I-IV
2. Plunger with a dia of 152+-0.5 mm and minimum depth of piston 25.0 m
3. Baseplate: Minimum Thickness 10 mm and length of each side of square 200 to 300 mm
4. Tamping Rod made out of straight iron with a dia of 16 mm.
5. Balance: Minmum capacity 3 kg and accuracy upto 1 g.
6.Test Sieves: Test sieves with square holes of 14.0 mm and 10.00 mm. Test sieves have to comply with BS 410 code.
7. A Compression Testing Machine with a capacity of applying 400 KN and capable of giving 400 KN load at uniform rate at 10.0 min.
8. A rubber Mallet
9. A metal Tray
10. A brush
Procedure of testing Aggregate Crushing Value (ACV):
1. Make a sieve analysis and get sufficient amount of aggregate by using 14.0 mm passing sieve and 10.00 mm retained sieve.
2. After sieving fill the cylinder in thre layers by the aggregate and apply 25 blows by the tamping rod with a approximate height of 50 mm.
3. Dry the material at a temperature of 110 degree centigrade and allow to cool it.
4. Place the cylinder with the baseplate under compression testing machine and apply 400 KN load at a uniform rate to aomplete the overall process at 10 min.
5. Release the load and remove the crushed aggregates after more or less than 10 minutes. Clean the entire cylinder with bruss and rubber mallett.
6. Sieve the crushed aggregate using a 2.36 mm sieve. eigh and record the masses passing and retained on the sieve( Let say them A & B respectively).
Calculation: Aggregate Crushing Value (ACV)=(A/C) X 100
Where , C= Mass of test specimen.
and A=Mass passing through 2.36 mm sieve.