Different Tests On Aggregate.
DIFFERENT TESTS ON AGGREGATE .
1)AIV test
Apparatus Required:
- Base Plate
- Cylindrical steel cup of depth 50mm and dia 102mm.
- Metal hammer of weight 13.5kg to 14kg, length 50mm and dia 100mm
- Height 380mm
b) Sieves
-12.5mm -10mm and -2.36mm
c) Cylindrical Measure of 75mm dia and 50mm depth
d) Tamping Rod
e) Balance
f) Oven
Procedure:
-Take a sample of aggregate passing through 12.5mm sieve and retaining on 10mm sieve.
- Dry the sample in the oven for 4 hr at temperature 100 to 110°C.
-Fill the cylindrical measure in 3 layers of aggregate. Each layer is tamped 25 times using a tamping rod. level the top surface of aggregate.
-Measure the sample . (Wt. of measure + Wt. of sample= W1)
-Measure the Wt. of measure . (W2)
-Calculate Wt. of sample. (W1-W2)
-Transfer the sample to steel cup and tamp it by 25 blows.
-The impact hammer is released and raised and impact is given to the sample for 15 times .
-Then the sample is sieved using 2.36mm sieve. Then the Wt. of sample passed through the sieve is measured. ( W3)
Calculation:
Aggregate Impact Value =
W3/(W1-W2) *100
2) ACV Test
Apparatus Required:
a) 15cm dia open-ended cylinder (Testing Mould).
b) 45cm long tamping rod with 16mm dia.
c) Measuring Cylinder (11.5mm dia, 18mm long)
d) Sieves (12.5mm, 10mm, 2.36mm)
e) Balance
f) Compression Testing Machine
Procedure:
-Take a sample of aggregate passing through sieve of 12.5mm and retaining on 10mm sieve.
-Dry the sample in oven at 100 to 110°C.
-Fill the measuring cylinder by the sample in 3 layers. Each layer is tamped 25 times using a tamping rod. Level the top surface of aggregate.
-Measure the sample . (Wt. of measure + Wt. of sample= W1)
-Measure the Wt. of measure . (W2)
-Calculate Wt. of sample. (W1-W2)
-Transfer the sample into the testing mould and tamp it by 25 blows.
-The plunger is placed and the setup is done in the compression testing machine.
-The load is applied uniformly such that the total load reaches 40 tons in 10 minutes.
-Then the sample is sieved using 2.36mm sieve. Then the Wt. of sample passed through the sieve is measured. ( W3)
Aggregate Crushing Valu
e = W3/(W1-W2) *100
3) Flakiness Index Test.
Apparatus required:
a) Flakiness gauge.
b) Sieves (20mm, 16mm, 12.5mm, 10mm, 6.3mm).
c) Balance.
Procedure:
- Take 1kg sample of aggregate.
- Arrange the sieve in ascending order from down to top. Place pan at the buttom.
- Place the aggregate sample at the top sieve.
- Shake the sieve thoroughly.
- Check the flakiness corresponding to the aggregate retained in the sieve size.
- The wt. of sample passing through each slot of the gauge is measured and noted .
Flakiness Index= Total wt. passing through various thikness slot/1000 *100
4) Elongation test
Apparatus required:
a) Elongation gauge.
b) Sieves (20mm, 16mm, 12.5mm, 10mm, 6.3mm).
c) Balance.
Procedure:
- Take 1kg sample of aggregate.
- Arrange the sieve in ascending order from down to top. Place the pan at the bottom.
- Place the aggregate sample at the top sieve.
- Shake the sieve thoroughly.
- Check the elongation corresponding to the aggregate retained in the sieve size.
- The wt. of sample retained through each slot of the gauge is measured and noted .
Flakiness Index= Total wt. retained on various length slots/1000 * 100