Glenn Kangiser wrote:If using just the natural resources on your land and you had clay without enough sand content ie: 30% clay 70% sand is ideal for most types of earth building, then it may be better to make your soil into adobe bricks. Without enough sand and aggregates, shrinkage will be a lot greater, therefore the bricks may work better.
Straw is your rebar and holds things together and if you were short on sand and aggregate, more straw could help in making the cob work without as much shrinkage as well as better reinforcement.
Cob is a monolithic structure usually with rounded walls and reinforced with straw, so it is immensely stronger than adobe brick walls and done properly will resist even large earthquakes.
In India they have developed methods of making mud bricks with interlocking sides and laid diagonally to resist earthquakes quite well also. They have also developed a method of putting a waterproof coating on the sides of the brick to prevent water damage... concrete and or rock chips etc on the exposed edge.