Can you describe how dry is "too dry" and how the mix feels when it's right?
Hard one as it changes throughout the process. Starts damp from stack
( our stack has been in place 1 year covered by plastic up till summer)
Placed on mixing slab and hoed level to produce even bed for addition of cement ( off white) drying all the time
improved depth control on rotary hoe worked well
now keeping it covered as much as possible
Add cement and mix through drying noticeably now but still mold-able
Loaded into truck and delivered to site kept covered continues to dry throughout the ramming process
Seems to me ideally would load into truck just a little too moist would be ideal perhaps extra moisture and mixing can be done in tipper body as day goes by
Well that's the theory I'm going with right now but time will tell
ps.today started with (1 m3 ) it seeming too damp but by the end of the day (6hrs mixed) it was approaching too dry
What was it about your end shutters which caused the tearout? I'm in the process of building mine now, and I'd like to avoid as much tearout as I can so it would be useful to know what to look out for.
i think it does not like obtuse ???? right angles anything too tight turns???
this is what i used for external corner ..... too fancy so planed off the ogee bits
bevels seem good bit early too tell yet still to strip forms after changes have been made
but original end shutters fairly interesting
before changes
after changes (however i did plane the bevel more than shown in this image)
From the photos, it looks as if you've placed your end shutters against the z-bars, is this correct? I did this when I rammed my little test block, and found that ramming the initial layers below the level of the first bar caused the shutter to push off vertical (which was then impossible to correct). Is this the sort of thing you had to deal with?
pretty much .... however i did not realize the relationship between the end shutter , form panel and the corner join
ie. as the pressure moves the end shutter outward the panel connected to the shutter moves also the result being the corner join tends to open up
end bracing and angles attached to the base of the end shutters seemed to solve that problem whatever method works just dont allow end shutter any movement
I've been doing these sums myself recently, basing my maths off Bluey's 1.75:1 loose:rammed ratio. It seems that your material is a lot more dense to begin with, if you're only using 1.3m3 loose material to ram 1.0m3 of wall. Do you think this is related to the moisture level (a dry mix not compacting as much) or is it that no two soils are alike?
our material has been in a heap for nearly 12 mths ... compacting all the time .. it is dug out with excavator which can dig without much disturbance so what comes out is pretty solid and its about 10- 15 % clay with quartz pebble and sand
i have previously used it in stabilized pressed brick with excellent results
I'm also interested to know what your cement to soil ratio is, and how you calculated it. I can't find any reference to the volume of cement contained in a 20kg bag, so I'm struggling to accurately determine the ratio of bags per m3 of soil since I can't weigh my soil. Any tips here would be appreciated
i have been using middletons observations
Calculations on materials
1m3 of RE wall requires 1.6 m3 loose soil
@ 8% cement loose vol = 0.08 m3 cement
/ m3 of loose earth
Therefore 0.128 m3 for ea m3 of wall
Cement = 1500 kgs / m3
Our job @ 2.4 m high walls without cut outs for windows and doors = 39 m3 x .13
= 7.6 ton of cement
this is how i am metering
seemed to work ok today only had 1 wheel barrow left over
these few images show the on site material handling process
tomorrow we shall strip the forms and see the results... fingers crossed its better than the first attempt
Login
FAQ
Search
