Proper mix for making good CEB
Thank you, Geoffrey for answering my many questions. I appreciate you sharing your knowledge and experience.
I've read that the ideal soil mix for solid CEBs is:
15% gravel (2-20 mm)
50% sand (0.06-2 mm)
What are your thoughts on this ideal mix?
Our soil here is very sand with measurable amounts of silt and clay in various places (up to 20% clay and silt combined).
The remander of our soil is fine sand (80%) with essentially no gravel. Is some gravel essential to a strong CEB block? What minimum percentage would you suggest? Gravel will have to be purchased whereas the sand and clay can be found in vllagers' fields.
Also, I am finding it a challenge to distinguish clay from silt. Do you have any suggestions for doing so?