concrete surface problems

Hi all,

On one part of my concrete patio I'm getting a white powder buildup on the edge of the concrete. I thought this was just from salts from the surrounding dirt, however it seems to be affecting the surface of the concrete itself. In particular, the surface of the concrete is flaking and brittle and the aggregate is starting to be exposed.

Any ideas and solutions?

Edit: Actually this looks like the issue http://www.radonseal.com/radon-faq.htm#efflo


Thanks in advance,
Jeremy

Efflorescence is pretty common with concrete products, and also clay pavers. The natural salts come through the surface and there's not much you can do in most cases bar either waiting for it to disappear or getting something like "Anti-Eff" which gets rid of it. This can be bought at paving suppliers

Although I have seen some concrete slabs have a whitish powder on top and a weak surface from being too wet during screeding and thus having a higher water content being weaker once set.