Soundness test of aggregate

• Soundness test of aggregate is to determine the resistance of aggregates for weathering action like variation of temperature, rain, throws etc.
• The porous and less density aggregates are more prone to freezing and throwing action also the disintegration is quick and premature.
• Using such aggregates in road construction is not only degrade the road quality but can cause accidents and poor-quality road work.

Soundness test of aggregate

Objective:

To determine the resistance of aggregate against weathering action and to check durability of aggregates.

IS Code: IS: 2386 part-V.

Apparatus:

Balance: 500gm (0.1gm least count)

            5000gm (1gm least count)

Oven

Sieve: 80 mm, 63 mm, 40 mm, 31.5 mm, 25 mm, 20 mm, 16 mm, 12.5 mm, 10 mm, 8.0 mm, 4.75 mm, 4.0 mm, 2.36 mm, 1.18 mm, 600 micron, 300 micron, 150 micron

Wire mesh basket

Container

Chemicals:

• Sodium Sulphate Solution
• Magnesium Sulphate Solution

Preparation of sample:

For example: For Fine aggregates

Passing on	Retained on	Sample weight
10 mm	4.75 mm	100gm
4.75 mm	2.36 mm	100gm
2.36 mm	1.18 mm	100gm
1.18 mm	600 micron	100gm
600 micron	300 micron	100gm

For Coarse aggregates:

Size	Sample weight
10 mm to 4.75 mm	1000gm
20 mm to 10 mm	1000gm
40 mm to 20 mm	1000gm
63 mm to 40 mm	1000gm
80 mm and larger	1000gm

Procedure:

1. Take the weight of sample as W1 gm.
2. Immerse the sample in solution eighter of sodium sulphate or magnesium sulphate at least for16 to 18 hours.
3. After that remove sample from solution and drain the solution completely and allow it to drain for 15 minutes.
4. Dry the sample in oven at 105 to 110⁰C temperature
5. Repeat this immerging and drying process 5 times for individual sample.
6. After 5^th cycle note down the dry weight of sample as W2 gm.

Result:

Percentage loss = (W1-W2) x 100/W2

 REPORT

The should be reported in following manners,

• Type of solution used:
• Range of sieve size selected:
• Weight of sample before test (W1) gm
• Weight of sample after test (W2) gm
• Percentage loss: