# ASTM C127 submerged weight and SSD weight?

in ASTM C127 Aggregate test , why the weight of SSD is higher than water submerged weight?

## Answers and Replies

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Baluncore
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Specific gravity, SG, of rock must have the SG of water (= 1) subtracted when rock is submerged to account for buoyancy.
If rock SG=3 and weighs 3 tonne, then when submerged in water it will weigh 2 tonne.
The weight of any water in the aggregate dissapears when it is submerged as it becomes part of the water.

goldfish9776
Specific gravity, SG, of rock must have the SG of water (= 1) subtracted when rock is submerged to account for buoyancy.
If rock SG=3 and weighs 3 tonne, then when submerged in water it will weigh 2 tonne.
The weight of any water in the aggregate dissapears when it is submerged as it becomes part of the water.
tas why we will always feel that we will be lighter when we are in the water ?

Baluncore
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will always feel that we will be lighter when we are in the water ?
Yes.
Our body is made mostly of water. But our lungs are lighter and our bones are heavier, so our bodies have a density very close to that of water.
When we breath in, with lungs full of air we float. When we breath out, the weight of our bones sinks us. More fat makes us float better because it has a density less than water.