Zkrib, I just got back to Birmingham and dug up some old mix design spreadsheets from those days. The info's dated by about 7 years, but at the time, white cement cost $183/ton to gray's $78/ton, just to give you a very rough idea of the cost difference (even though it looks like it's probably moot at this point). It's a shame, though. I agree with you that a white wall would look fantastic.
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Originally posted by Lancer View Post...
Zkrib, Theresa mentioned to Dolores that she's thinking of "retiring".
Solomwi -- Wow, thanks for that effort! So it looks like about a 2.5:1 cost ratio. Plus the cost of a white aggregate. And I'll bet the rarity of its use in the Philippines will increase that cost ratio even higher. The chances for this plan are really grim.
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Originally posted by snoopy369 View Posthttp://en.wikipedia.org/wiki/White_Portland_cement btw ... generally confirms Solomwi's statement. More expensive, requires special process to make, using higher quality clay and limestone and such.
You might check with Grandpa Troll as well, iirc he's in the construction business and might know a thing or four.
Actually, I am an Area Manager with S & W Ready Mix Concrete, with 24 years experience.
I deal with design and control of mixes for my area, and specialty products including colored concrete.
First off, economically speaking, unless you have a very local source, White pigmented cement is extremely expensive and in most cases, cost prohibitive.
Alternates practices we use are this:
1) use a Straight Portland cement mix design, NO POZZOLAN's such as FlyAsh,NuCem or GGBFS (Ground Granulated Blast Furnce Slag).
Due to pigmentation issues inherent with all cement, a variety of hues will come through different brands of cement, from a greenish/yellowish to a brownish or even blueish tint or hue. Best to use a pigmentation of integrated coloring. Dry shake works well for flat surfaces but then if a surface becomes marred/scratched the original color will show through
When dealing with "Formwork" such as a wall, using a system such as a Symons Wall System or Plywood, be careful of staining and and imperfections in the forming material. Extreme care must be taken when using a steel form as form releash agent is used plus in the extreme heat these forms expedite hydration or the chemical reaction between water and cement, thus often a flash set causing a darker area.
This brings us to admixtures, to help offset the quick setting, darkening caused by a flash set, use a set retarder. if in a form, extra time will be needed as the forms will be subjected to a slightly slower set. Plus the lower w/c ratio (water in pounds to cement in pounds) makes a more durable mix. It takes only about 2-3 gallons of water per 94 Lb. sack of cement, normally in a 3000 pound mix, 5 sacks of portland cement is needed. (So out of a normal 33 gallons of water (weighing each at 8.33 Gallons=a total of 274 pounds divided by 470 pounds of cement = a .58 water-to-cement ratio, plenty durable for that area. I had to correct the gallons per sack, as a clarification).This start Hydration but the rest of the mix in a cubic yard of concrete is "Water of convenience" or allowing you to place with ease the concrete. Using a water reducer (5-10% reduction in water, or a MRWR (Mid Range) 10-18% roughly water reduction or even a Super plasticizer 22% to 30 % give a much more fluid,workable mix with a very durable,water tight and lower w/c ratio mix
One other point is the aggregates used.
A) Coarse Aggregates being a lighter shade help greatly in color control as does your fine aggregate selection. Natural 2S fine aggregate or sand tends to run lighter than a 2MS or manufactured sand. Of course depending upon where they are excavating, sometimes silicants appear causing a darker run. 2S runs from a blondish,whitish to orangish and even brownish tint.
GrampsLast edited by Grandpa Troll; March 21, 2009, 08:13. Reason: To correct a technical portion of information a Tired Gramps had givenHi, I'm RAH and I'm a Benaholic.-rah
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Originally posted by Solomwi View PostChiming in without enough information about the specific situation to justify it here, but the only way I'm aware of to do that is using white cement (typically significantly more expensive than gray) and white aggregate (may or may not be available there).Try http://wordforge.net/index.php for discussion and debate.
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Originally posted by Solomwi View PostZkrib, I just got back to Birmingham and dug up some old mix design spreadsheets from those days. The info's dated by about 7 years, but at the time, white cement cost $183/ton to gray's $78/ton, just to give you a very rough idea of the cost difference (even though it looks like it's probably moot at this point). It's a shame, though. I agree with you that a white wall would look fantastic.
Nice information Solomwi
Regional exceptions, such as my area, coastal North carolina i oversea, building in a frenzy, limited sources, drives cost upward.
i did myself a cost for LANTDIV (Atlantic Division Norfolk) for the U S Navy, they had to have white pigmented columns on a BEQ (Bachelor Enlisted quarters). the three closest sources for White pigmented cement were Georgia,Alabama and Ohio.
I would have had to purchase a tanker since it wasnt feasible to set a third Silo (Type 1/II Cement in one and Type F Flyash in other) so the cost at the time, a normal Ready Mix 3500 PSI was at $ 66.00 cyd and with the White Pigmented cement would have sent the cost to $ 295.00 per cubic yard due to operational costs to set up.
The caveat was we would not guarantee end result since we dont control the practice or placement of the concrete. Cantileaver walkways were also needing to be white and they use steel forms and form release agents, and if you ever see one of these forms then you know its a mess to control the facing.
Of course that was about 7 years ago, now a normal per cubic yard price is $ 128.00 and no telling what white pigmented cement would run. Not including the environmental changes in place meaning we would need an additional reclaimer as we are maxed out in production levels with the current one.
This is what drives costs up so darned high
GrampsHi, I'm RAH and I'm a Benaholic.-rah
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Originally posted by Oerdin View PostThere are volcanoes in the PI so it should be possible to find pegmatite to use as white aggregate.Hi, I'm RAH and I'm a Benaholic.-rah
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Originally posted by snoopy369 View PostForgot about your specialty GT, glad to know my feeling you'd know something was spot on
In my sleep, need to get away from reality..er.work and go relax..one..more..turn..Hi, I'm RAH and I'm a Benaholic.-rah
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Interesting info guys, thanks.
I spoke with Sho and he knows about white cement, he says they sell it at LM hardware here in Jagna. (munches words) Will find out details on Monday.Long time member @ Apolyton
Civilization player since the dawn of time
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Originally posted by Lancer View PostInteresting info guys, thanks.
I spoke with Sho and he knows about white cement, he says they sell it at LM hardware here in Jagna. (munches words) Will find out details on Monday.Solomwi is very wise. - Imran Siddiqui
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