Author Topic: OH OH Quick Question  (Read 849 times)

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Offline Whiskyb

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OH OH Quick Question
« on: November 11, 2012, 07:44:38 PM »
Today mt wife and I poured our structural layer of concrete and the our mix of vermiculite and concrete on top.

So my quick question that i have not been able to find an answer to. Should I keep the top moist as it cures? Cover and let dry? We have about another 2-3 days before it gets cold again. Below freezing at night.

Any helpful pointers greatly appreciated,



Offline pizzaneer

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Re: OH OH Quick Question
« Reply #1 on: November 11, 2012, 07:54:26 PM »
soak it with a hose then cover it. repeat every day for five days.  it will be stronger than just letting it dry.
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Offline Tscarborough

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Re: OH OH Quick Question
« Reply #2 on: November 11, 2012, 07:55:40 PM »
Once the concrete/perlcrete has achieved initial set (1-10 hours) freezing will not hurt it, although it will slow the cure to ultimate strength.  Tarp it with no additional moisture added and you are GTG.

Offline Tscarborough

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Re: OH OH Quick Question
« Reply #3 on: November 11, 2012, 08:07:08 PM »
Just for general knowledge, let me explain how it works.

For concrete and cementious stucco, all the moisture that is required for ultimate strength is contained in the initial mix.  Nothing is added by adding more water in neutral conditions.  Under conditions that sap the initial moisture (high temps and high winds), then the work needs to be protected or moisture added.  Use 75 degrees, 80% humidity and zero winds as your baseline to decide if you need to take steps to add moisture or protect the work from excessive evaporation.

Also realize that you are working to extract the final 20% of design strength and decide if it is required or worth it for the extra effort.  Good design dictates a 50% safety factor, and for what we are doing here, the safety factor outside of seismic areas is 80% plus.

Offline Whiskyb

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Re: OH OH Quick Question
« Reply #4 on: November 12, 2012, 06:05:49 AM »
Thanks, Once this sets the fun will begin :)


 

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