SOIL STRENGTH MATTERS
Wall strength tests completed by BSI late in 2016 show clearly that strong adobe-type soil can increase strength of contained earth walls dramatically over weaker soils, and may more than double wall strength compared to barely cohesive silty soil.
Builders need simple and quick ways to check the strength of soils without labs or high costs. BSI's 2017 field soil test booklet benefits from donors funding lab tests to relate small tests to real unconfined compressive strength. It also benefits from two months donated by intern Christian Ernstsen during mid-2016 to improve test equipment and protocols.
Quick Cured Tests Take 12- 24 hours
Dry some egg-sized balls. Crush them under a light weight person wearing a soft shoe.
Cured Unit Tests Take 1- 2 days
Exactly how strong is this soil?
Quickly test different mixes to get the best quality from local ingredients.
Use the tubes from toilet paper rolls to make fist-sized samples. When dry, crush them under a simple wood lever, using buckets of water
MORE INFORMATION ABOUT SOIL STRENGTH AND SOIL TESTS
These slide shows include a wealth of background information, including how to recognize sand, silt and clay by squeezing damp soil in one hand, and how to test clays for expansive/ shrinking problems.
These will all be updated during early 2017 to include information from the 2017 field test booklet..