Water rise in concrete due to capillary 2

[dan00]

Is there any relationship between type of concrete and water rise due to combination of capillary, absorption and various pressures? Is there a maximum distance which water will rise through concrete due to capillary? Thanks. Any reference would be greatly appreciated.

 

[emmgjld]

I do not remember any relationships. My own experience has been up to 5 feet of 'capillary rise in older (1920's) concrete. I have noticed that moisture rise appears to be significantly less in the modern, somewhat more dense concretes. This is an interesting question.

 

[Ron]

emmgjld has pointed out several of the limiting factors for capillary rise of water in concrete. Air entrained concrete will have less capillary rise than non-air entrained concrete.

Vapor pressures and vapor drive will have some effect on the rise, though that primarily affects thinner sections such as floor slabs.

The pore structure coupled with the absorption of the coarse aggregate will have the greatest effects on capillary rise.

 

[onteng]

Check out the Portland Cement Association store web site. They have made available a new publication 'Concrete Floors and Moisture'. Just got my copy today and haven't had a chance to read it all.
My biggest concern was vapour movements through the slab and its relationship with flooring failures. What I read so far backs ACI302 requirements for a combination of a drainage layer and a vapour retarder directly under the slab.