Hormigones vs. mixing small batches by hand using bags of concrete

reilleyp

Active member
Dec 12, 2006
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One local said he preferred to mix concrete in small batches using bags of cement, sand, stone etc mixed by hand or small machine, instead of ordering a whole truck of concrete. He felt that the concrete trucks used bulk cement that was treated with chemicals to prevent premature hardening or caking due to the very humid environment in the DR. He felt the chemical additives weakened the final product. The bagged cement made in smaller batches did not harden as quickly, since it has a plastic wrapper, compared to bulk cement which may be exposed to the elements. Seems logical but I have done a little research and I cannot find any chemical additive that prevents cement from hardening in high humidity environments. Does anyone know if they treat cement to prevent hardening? With what? Does it affect the final product so that if you retard hardening in the short run, will the treated bulk concrete have less strength than untreated bagged cement?
 

sayanora

Silver
Feb 22, 2012
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The large hormigone companies have strict regulations as to the strength of their mix. They are regularly tested and if you ask for proof they will even explain to you why they are superior over hand mixing/trompo (my experience with Cemex). I have also mixed for pours using a trompo and there is an additive we used and as far as I understood it was almost a sort of plastic that is added to the cement to increase elasticity ?? (been like 2 years now).
 

william webster

Platinum
Jan 16, 2009
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My friend the engineer who builds hotels all over the world says that Dominican cement is some of the best he has ever encountered.

A Dominican cement company just won a world wide award for exceptional use of cement in a difficult design 

Your friend's ideas about the tainted trucks is wrong.
 

dv8

Gold
Sep 27, 2006
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i trust the quality of hormigones. there is a reason they are used in commercial structures. the quality of the mix is more uniform and the results are better. pouring and "shaping" (for the lack of a better word) takes relatively short time as well.
 

reilleyp

Active member
Dec 12, 2006
537
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All good info.  Thanks.  His info did not sound correct to me.  Maybe they just added too much water to his in an attempt to extend his finishing time, which will weaken it.