Rock salt on my concrete driveway

[jinman]

That's unfortunate Jim. I think someone told me that the salt makes hydrochloric acid with the water and dissolves the cement in the concrete. Anything that makes an acidic mixture will have the same effect.

I'm sure not disputing what you say, but I can mix salt and water all day that never becomes HCl. My mouthwash is a mixture of salt, water, and baking soda. It is suggested as a non-acidic mouthwash for people prone to acid sores. My wife thinks the damage occurred when the ice refroze. Her theory is the salt allowed the water to soak into the surface of the concrete and then refreezing popped these little discs of surface concrete up. I don't really see dissolved concrete as you'd normally see with HCl. I'm inclined to agree with my wife's theory because it fits so well with what I'm seeing. It doesn't matter really. I now know not to do it anymore.

 

[bigtiller]

I was told years ago that if the concrete finish is worked up good with a wood float before troweling, it would tolerate salt in the winter better than just using a magnesium trowel. They say it works the aggregate further down and leaving a little more gravy on top for a little more protection.

Has anyone in the business an opinion about this?

 

[drifter2518]

I just took a couple of photos of the worst spots on my driveway. These are both about 3'x3'. I won't be doin' anymore salt here. I can use it on my deck and steps, but not on the concrete.

View attachment 352215View attachment 352216[ If you do just the deck and steps leave a mat before the driveway or your shoes will carry the salt on your concrete. If you don't wipe your feet you will leave foot print marks on the concrete.

 

[sixdogs]

I started a thread on this a while back--search for it--and what I recall was that a higher PSI mix was less likely to pit and a lower PSI mix more likely to pit. Sealers helped but I don't think that was the final answer. I really sealed mine good and put no salt on it and hope I can stop or at least slow down the process..

 

[Rustyiron]

My wife thinks the damage occurred when the ice refroze. Her theory is the salt allowed the water to soak into the surface of the concrete and then refreezing popped these little discs of surface concrete up. .

This is what I have heard actually causes it to "spall". Not sure if exactly as she said, but the re freezing part was in the explanation.

 

[mjcountrybumpkin]

I worked in concrete coating business for several years , from my experience it is a combination of a poor quality finish and cheap concrete made visible sooner by the application of salt.
You might as well use salt because the whole surface will do it eventually. A good commercial sealer would greatly slow the process. Google Sure Crete, they have a very high quality outdoor sealer that is very effective.

 

[jinman]

My driveway has been in for 12 years with no other issues. It may not be the best, but is has been trouble free. We really have mostly mild winters and this is the first time I've ever applied salt. I will Google Sure-Crete and see if it is carried locally at Lowes or HD. Thanks for the tip.

 

[mjcountrybumpkin]

I apologize if what I said offended you. Spalling is typical of concrete that has had to much water added, overworked in the finishing process ,or just didn't have enough cement in the mix to start with. The sealer , whatever brand you may use , should be a penetrating type.
It will actually do more as a binder than a sealer in that respect to keep the rest of the spalling at bay.

 

[salopez]

From what I have seen..... if you keep the ice/snow wet you won't have spalling problems.

I use a chemical that keeps water wet to about -10 so I am good here in Maryland. If you melt the snow the water goes into the concrete. If it freezes it can pop. Don't let it freeze.

If skim coating won't fix it there is a product called Roklin that will.

 

[jinman]

I apologize if what I said offended you. Spalling is typical of concrete that has had to much water added, overworked in the finishing process ,or just didn't have enough cement in the mix to start with. The sealer , whatever brand you may use , should be a penetrating type.
It will actually do more as a binder than a sealer in that respect to keep the rest of the spalling at bay.

No apology needed or expected. I was just trying to show why I was so surprised to see the damage. My concrete contractor was less than ideal. Many contractors are sloppy out in the country in Texas where no inspection is required. If you are not there, they cover up rather than fix mistakes. In one instance, this contractor poured over 9 yards of concrete for back-fill in an area that should have been formed and back-filled with dirt.