# WHY is my new poured porch SO DUSTY??



## bluethumbnail (Nov 5, 2005)

Hi everyone, I need some advice, please. I recently poured a new front porch using 80# bags of Quickrete concrete mix (took 25 bags) by portable mixer and troweled to finish. Now, just a few days later, she (my customer) keeps sweeping and it keeps putting off a cloud of dust! I've tried hosing it off a couple of times but to no avail. I've done concrete this way before but, I've never seen this happen. What did I do wrong? Any ideas? Thanks.:sad:


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## Brickie (Jun 15, 2006)

http://www.concretenetwork.com/concrete/slabs/curing.htm


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## tkle (Apr 15, 2006)

You used Quikcrete.It's crap.We just went through a thread on it.It has a low cement ratio and always seems to have had some moisture in the bag.Not enough to make it chunky,just enough to make it course and weaker due to partial hydrolization of the cement.There's better quality premixs out there.Twentyfive bags though?Why didn't you go from scratch?


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## Tscarborough (Feb 25, 2006)

The crapiness of bagged concrete aside, it sounds like it was overworked with the float and underworked with the hard trowel, as well as left to cure on it's own.


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## tkle (Apr 15, 2006)

Living in an area where the temps can easily get up to 120,I haven't seen anybody cure a slab in years.I've never seen it cause this problem or any problems for that matter.Overfloating and lack of hard troweling.Bringing too much soup to the top,possibly in combination with too much water could do it.Still a better product will produce a fatter more stable mix,less susceptible to these factors.


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## calypso (Dec 8, 2004)

I am trying out a product by Advanced Tech. I think that is the name. Anyway it is a sodium silicate solution that you brush or spray on. It reacts with the free calcium that hasn't been used in the slabs chemical reaction changing it into a calcium silicate that is similar to quartz. This hardens the surface, prevents efforvesence, eliminates dusting and waterproofs it producing a permanent seal that dosen't need to be reapplied. OK...it sounds like alot to ask but that's what the lable says. It is used on water tanks and parking garages etc.


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## Tscarborough (Feb 25, 2006)

Sodium Silicate is a common curing agent for concrete. It works well.


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## Long Star (Oct 11, 2006)

*Long Star*

keep wetting it down (do not rinse off)


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