Most cement blocks for walls here use a block that is 18.5 cm tall x 12 cm wide x 40 cm long. These blocks are mostly to fill space in the wall. The load is primarily borne by cement posts and cross beams.
I have a Cinva Ram press that presses blocks 13 cm tall x 16 cm wide x 35 cm long.My African mason friends already think my Cinva blocks are not tall enough nor long enough.
I'm concerned they will think the 10 cm x 15 cm x 30 cm block made by the BP6 is much too short vertically and will take much longer to build a wall with. Of course, not needing mortar between the blocks will mitigate that issue some.
I have three questions:
1) Does the BP6 press adjust to make taller blocks (up to 15 cm tall)?
2) Can the press blocks be laid on their sides (i.e. the15 cm side being the vertical and the 10 cm being on the horizontal)? 10 cm does not seem wide enough for a stable wall
3) Is it important to lay the blocks (in the wall) in the same horizon as the clay particles are compressed? I've read that during compression the platelike clay particles align horizontal to the compression (or perpendicular to the direction from which the compression comes) and this is the best way to lay them in the wall.
Thank you for your help with these questions.
The standard bond for earth blocks in Africa is 30 x 15 x 10 cm. This is according to Regional African Standard ARS 674 1996 http://www.cd3wd.com/cd3wd_40/cd3wd/CONSTRUC/H1713E/EN/B359.HTM Blocks made by our BP6 press meet this standard. The BP6 is adjustable so that blocks come out to this standard size but not larger sizes. Walls made from interlocking compressed earth blocks go up quickly because mortar is not used.
Our "Rhino Blocks" can be laid on their sides but not for load bearing. Regarding wall thickness:
Using empirical criteria in the 2005 edition of the Building Code Requirements for Masonry Structures (ACI 530/ASCE 5/TMS 402) developed by the Masonry Standards Joint Committee (MSJC), exterior walls are limited to an h/t (height to thickness) of 20 for solid or fully grouted bearing walls, and an h/t of 18 for all other exterior walls (non-loading bearing walls or bearing walls not solid or fully grouted).http://www.structuremag.org/article.aspx?articleID=663
Compressed earth blocks have more strength in the direction of compression. I have not made a comparrison between the strength in the 2 directions. The taller a block is the greater differential there is between the pressed side and the unpressed side of the block. The pressed side being the side in contact with the moving plate in the press. A very tall block would have some of the block at a low density.