I'm sure Judith is already aware of this, but I'll comment for the benefit of those that may be newer members.
I'd guess that Judith uses approx 60-75lbs of dry newspaper per 200 gallon mixer batch of papercrete. Using a half bag of cement would be around 47lbs of cement.
If those were the ONLY ingredients Judith was using, her final cured/dried papercrete would likely burn ... or at least continue to smolder... if it were exposed to flame. This is especially true if the slurry does not get compressed.
Adding clay or flyash, or other fine mineral content can make up for the cement reduction when it comes to fire retardancy of papercrete.
Adding Borax can also retard smolderability, but I've never heard Judith mention borax.
I'm all in favor of reducing the amount of cement required in papercrete, but I encourage everyone to add in enough other things to inhibit flamability/ smolderability. If you have the natural clay already in the ground on your site, it sure makes sense to use it.
Food for thought.
--- In
papercreters@ yahoogroups. com, JUDITH WILLIAMS <williams_judith@ ...> wrote:
>
>
> If you have added cement tot he mix it will not break down and mulch into another mix. Cement is actually made stronger by being in water. if you had used clay soil in stead of cement you could re-use the finished stuff in the next batch.
>
> I use pumice in place of sand in my mix. It is lighter and adds R value, but it may not be available where you are. I just found out the pumice plant near me closed down so I am going to switch to perlite when it's time to get more. I looked it up on google and it seems to be found in more areas than pumice. They are both volcanic rocks but perlite is actually glass. You can get it in the raw state when it looks like crushed rock or in the processed state like what you see in plant pots.
>
> I don't use much cement in my mix. I started out with 2 bags per 200 gal mix but am now down to 1/2 bag or less. The blocks are every bit as strong but so much lighter. I recently moved a bunch of old blocks and was astounded at how heavy my original blocks were. My whole motive for using this stuff is to keep things light and manageable for myself, not being a bodybuilder or anything close to it.
>
> Sincerely, Judith
> Visit my new website at
http://www.papercre tebyjudith. com>
EMAILING FOR THE GREATER GOOD
