I'm doing this special project where I have to make concrete using a Martian simulant provided from a commercial source.

I measured it as 500 grams initially, then submerged it in water for a day. It came back as 727 grams, meaning that it gained 200 grams of water, as it is now in its saturated surface dry state.

$$A = \dfrac{W_{SSD} - W_{OD}}{W_{OD}}\times100\%$$

Following this equation to measure the absorption value, it would mean that the value would be around 50%, which is very high. Usually, normal aggregates on Earth have an absorption rate of around 10%!

Is there anything that I may have been doing wrong? I am very skeptical of my results

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    $\begingroup$ When you state you submerged 500 g of Martian soil simulant in water for a day and then measured it, did you drain the surplus water prior to taking the second measurement of 727 g? What was your process for taking and measuring a wet/moist sample? $\endgroup$ – Fred Mar 16 '20 at 5:45
  • $\begingroup$ What was the other 27 grams then as 727 - 500 = 227 but you state 200 ? $\endgroup$ – Solar Mike Mar 16 '20 at 6:21

Clay can absorb almost 40% water at saturation.

The Amount of water aggregate can hold depends on many factors, e.g., its size (the smaller the more surface) and texture.

There are many methods for measuring the saturation of a soil sample but they require established labs. I assume you have measured your sample correctly.

However, considering the huge difference in the development process on the Earth and Mars and totally different erosion systems and how authentic your simulant is, there are too many variables to be looked into.


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