Need a book? Engineering books recommendations...

Return to index: [Subject] [Thread] [Date] [Author]

RE: Rammed earth construction

[Subject Prev][Subject Next][Thread Prev][Thread Next]
I actually have that book.  I have a condition where I need to have
ledgers at the mid-height of the wall.  In that book, the author quoted
some testing values for a few different type of anchors.  I'm not sure
if that's any consensus on those values (with a big safety factor I


From: erik_g(--nospam--at) [mailto:erik_g(--nospam--at)] 
Sent: Tuesday, November 04, 2008 9:20 AM
To: seaint(--nospam--at)
Subject: RE: Rammed earth construction

    Yi, I have the book written by Bruce King, "Buildings of Earth and
Straw" and shear transfer into the wall from the roof diaphram can be
accomplished in a few ways. One way is to provide a reinforced concrete
bond beam at the top & centered in the rammed earth wall, almost like a
key. Then your ledger or sill plate is anchored into this conc beam and
your joists are attached to the sill or ledger. 
    I'm sure if a person is creative enough there are probably a lot of
other ways to accomplish shear transfer.
Erik Gibbs
 -----Original Message-----
From: Yi Yang [mailto:YI(--nospam--at)]
Sent: Monday, November 03, 2008 5:06 PM
To: seaint(--nospam--at)
Subject: RE: Rammed earth construction

	I'm curious on how you get anchor values (epoxy anchor I
assume), say in a ledger condition.


	From: Thor Tandy [mailto:vicpeng(--nospam--at)] 
	Sent: Friday, October 31, 2008 9:39 AM
	To: seaint(--nospam--at)
	Subject: RE: Rammed earth construction
	I do RE in BC, Canada.  If I can help ...
	1)  Get lab tests done on the available material - material is
site-specific and needs care in selection.
	2)  Generate several particle-size gradings of the material and
develop "mixes" that when tested give the "best" behaviour.
	3)  Decide what, if any, admixtures you might want to add.  Eg:
cement, flyash, other pozzolans etc that may be beneficial to the final
working material.
	4)  If you decide to go reinforced RE and cement stabilized RE
then make sure that you are comfortable using the masonry block design
standards.  Most engineers use masonry or concrete.  While masonry
approximates what is essentially a cement-stabilized aggregate, I'm not
convinced yet.
	5)  For further information on material choice, SIREWall Inc
here on Saltspring Island, BC has over 15 years of aggregate sampling
experience, design of RE structures, and has a fund of knowledge on the
behaviours of RE material in Canada, China and the US.  I am one of
their structural consultants so we familiar with their work.
	6)  I don't know Rwandan climates but while RE does perform well
in wet and cold climes, it is prudent to design with reasonably large
overhangs of the roof.  Verandahs are an excellent way to protect.
	7)  If you go with cement-stabilized RE then curing is as
important as in conc. construction.
	8)  There is a lot of info on the internet.  Peter Walker of
Bath University, UK has done much research on un-reinforced RE and Kepa
Morgan of Auckland University, NZ and done a lot of work with
fibre-reinforced RE.  If you go with unreinforced and no-additive RE
then I recommend those 2 Profs will be of great help.
	Hope this helps you get started.  If you need any further
assistance then please contact me privately.

	Thor A. Tandy P.Eng, C.Eng, Struct.Eng, MIStructE
	UNISOL Engineering Ltd
	Unit 7 - 625 Hillside Ave
	Victoria, BC, V8T 1Z1
	Tel/Fax: (250) 382-9115
	Email: vicpeng(--nospam--at)

		-----Original Message-----
		From: Michael Hemstad [mailto:mhemstad(--nospam--at)]
		Sent: Friday, October 31, 2008 10:17 AM
		To: seaint(--nospam--at)
		Subject: Rammed earth construction
		I have a project in Rwanda on which my client wants to
try some alternative means of construction.  Rammed earth and straw bale
construction have come up.
		(For those who haven't heard of these, rammed earth is
made by building wall forms, placing soil in them, and pounding it until
it rings.  It makes a durable, fireproof wall with local materials and
labor.  Straw-bale construction involves stacking straw bales, often
dowelling them together with wood dowels, then applying thick parging to
each side.   This apparently results in a strong, fireproof, relatively
durable wall too, although I know less about it than rammed earth.)  
		Does anyone have information on either of these?  I am
specifically looking for information on what soil properties are needed
for a successful rammed-earth installation (e.g. clay content, sand
content, moisture content).  I don't yet know whether a geotechnical
engineer is available to the project; so information of the "holds
together as a ball when dropped" type is also appreciated.
		I appreciate any help, or alternate suggestions.
		Mike Hemstad, P.E., S.E.
		Minneapolis, Minnesota