Thursday, June 25, 2009

[papercreters] Re: Recipe Ratios




--- In papercreters@yahoogroups.com, "slurryguy" <slurryguy@...> wrote:

 Don't their blocks have holes in them? Similar to traditional concrete block or cinder block? That would dramatically change things compared to a typical solid block that most papercreters make.

No the blox he referred to in the file I have posted in the files section clearly is a adobe type block, and when asked how much it weighs he said 8.5 lbs. He does make other blox other than the adobe type that do indeed have holes similar to traditional concrete blocks or cinder blocks, I don't know how much he said those weigh. I think the way he gets the lighter weight is because he pours a slurry into forms there by traping air pockets as the water evaporates.
 
He goes on to say:

"Generally, as is well know in this art, strength of concrete is normally higher at lower water to cement ratios, but must be obtain with a compromise in materials to achieve a workable matrix for molding. Additionally, it is well know that concrete structures must achieve high compressive strength. Compressive strength is a function of a time dependent hydration reaction which occurs as moisture is added to the non-hydrated cement. Low water to cement ratios increase the compressive strength of the product significantly. Because air entrainment appears to lower the compressive strength of concrete at a given water to cement ratio, its use may seem problematical. However, air entrainment not only makes concrete more durable, especially under severe freeze-thaw conditions, but it also adds to the workability of the material in the molding stage, as measured by the slump test, which is used by artisans in this field to measure workability of the raw product. Workability must not be so great as to cause segregation or bleeding of the concrete. Bleeding is movement of water to the surface of the sample which suggests higher localized water to cement ratios and lower surface strength and durability of the poured material.

The moisture content of the mixed product is also highly important to the strength achieved by the mix. The reduction or removal of the surface moisture slows down or stops the hydration reaction. The interruption of moist curing of freshly poured concrete after a given period of time by exposure to dry air ultimately stops the curing of the poured material. Accordingly, moist cured building materials can exhibit increased compressive strength over those dried too rapidly.

Finally, temperature is another important factor to be controlled in the production of these building materials. As has been long known in this art field (in fact since Roman times), the hydration reaction in cement releases heat, and the rate of hydration is higher at higher temperatures. Therefore, the correct type of cement paste, the water to cement ratio and the treatment to achieve the optimal strength differ according to the ambient temperature. The provision of ovens with moist heating or steam blanketing is expected to more carefully control the time and temperature required for the production of materials made from the invention of the present application, all in manner well known to those in this art. "


 

--- In papercreters@yahoogroups.com, "Bob" criswells.ok@ wrote:

 
I just downloaded Masongreenstar quote from his patent #20090065978
 
"This building material composition in an uncured state is made up of
 between about:

    • Between about 70 & 74% weight water
    • Between about 7 & 8% by weight shredded paper
    • Between about 18 & 20% by weight cement (80% Portland and 20% flyash)
    • Between about 0.1 and 0.4% by weight cement conditioning admixtures (a lot of these are liquids)

       lets convert these %'s to lbs:

 

    • 74 lbs water (at approx 8 lbs per gallon), that would be about 9.25 gallons, (not a whole lot of water)
    • 8 lbs shredded paper (dry weight, not much paper compared to the cement content)
    • 20 lbs dry cement (I believe dry portland weighs about 5 lbs per gallon, that would be about 4 gallons, (that is an awful lot, and it would be really a lot if dry cement weighs more than 5 lbs per gallon)
    • 4 lbs other conditioning admixtures (way to much information listed here for me to understand, and also too much added cost as well, I would just stay with something simple like clay or sand.

 
I can't see where his 10 inch by 14 inch by 4 inch blocks could only weigh 8.5 lbs. I don't know for sure but I believe the above mixture would fit into my 9.5"hx12"wx16"l form and would compress down to about  6x12x16 and it would weigh 32 lbs once the water is pressed out. I got
 that 32 lb figure by adding the 8lbs paper, 20 lbs cement and 4 lbs  other. What are your thoughts on this? (after re-thinking this the four lbs are mostly liquid and would press out with the water so if that is so, the weight would be about 28 lbs, same as my second batch)

In my other post where I was referring to 2 gallons of slightly wet  paper pulp, I will have to weight the dry paper that got pulped to see  excatly how much dry weight I was referring to. I did not weigh the dry paper first I only dipped it out of the pulping container (draining it  through my fingers) and dropped it into a gallon container twice, and then into my mixing bucket.

 Thanks for the info.

 Bob



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