The soil mechanics lab at NYUPoly specializes in transparent soil research. Last week I included a picture of a jar of Aquabeads. Aquabeads are a water absorbing polymeric gel. They can absorb water up to 200 times its own weight. The following image shows what they look like dry on the left and gorged with water on the right.
For certain tests the Aquabeads can be used to model soil. The Aquabeads have the same refractive index as water. This means that a jar that contains swollen Aquabeads with water filling in the void spaces between the beads is transparent. We say that a sample is saturated when all the void spaces are filled with water. Here is the photo that I posted last week of an unsaturated beaker of Aquabeads:
We can make the sample transparent by adding water.
The bubbles of air are blocking transparency. We can tap the beaker to make them rise. Here are a few other examples with the Aquabeads:
So what makes a transparent soil useful? If we want to study something happening inside the soil, the transparent will allow us to see past the edges. This could be helpful to monitor what happens inside the soil when a force is applied or how a contaminant travels through soil. Russ and I will be carrying out research with transparent and nontransparent soils for the rest of our research experience. The fabrication of our soil permeability test is well on its way. I will feature that process in my next post.
Have a great day my good people!
This work is supported in part by the National Science Foundation under a Research Experience for Teachers (RET) Site grant EEC-0807286. We thank the Mechatronics Lab and the Soil Mechanics Lab for hosting us during our summer research program.