Question about concrete scaling.
House is less than a year old… and first winter sections of driveway are scaling.
Several other homes in the area that are less than a year old also have same driveway scaling and built by same builder.
One of the home owners had builder review driveway scaling during the 1 year warrantee and builder said it was due to road salts.
In my research
Article on concrete and chemicals. The way I read it is that chemicals should not damage the concrete if the correct mix was used. The concrete contractor should provide details of the mix that was used and evaluate the damage. Virginia Department of Transportation VDOT uses the both sodium chloride and magnesium chloride which the article states does not harm concrete with the proper mix. Do Deicers or Ice Melts Damage Concrete? — EVstudio, Architect Engineer Denver Evergreen Colorado, Austin Texas Architect
If this is correct any ideas on how to get the builder to reconsider their position on the scaling of the concrete ?
If the driveways were poured in the heat of summer most concrete contractors will add water to the mix to make finishing the mix easier. During the final finishing, the excess water bleeds to the top creating a thin weak layer. This is just one common possibility.
If the contractor finished the top surface of the concrete (broomed or float) prior to all of the bleed water coming out, this is often the cause of scaling or spalling.
Thanks for the info… is there anyway to test or analyze the driveways for improper workmanship or mix ? There are about 6-8 properties that have the same condition all poured within 12 months.
Not without sending core samples to a lab, but that would be too expensive. You can detect delaminated concrete before it pops off by using a hammer or piece of chain. See this article Concrete Delamination - Causes and How To Avoid Delaminated Concrete - The Concrete Network
The only way to prevent problems with concrete slabs or typical concrete flat work, is to have someone from a testing agency monitor the applications and installations.
Concrete is a touchy material to work with if you are not technically educated in its characteristics and all the variables that can affect its performance for the usage intended.
Below is an excerpt from the article that covers most of your problem.
For concrete that will be exposed to severe freezing and thawing conditions order good quality air
entrained concrete with a strength of 4000 psi [28 MPa]
Do not add excessive water and place concrete at a slump of 3 to 5 inches [75 to 125 mm].
Finish concrete after bleed water has dissipated and avoid using steel trowels when finishing.
Properly cure the concrete
Consider sealing the surface with a commercial breathable sealer.
Avoid the use of deicing chemicals in the first winter and subsequently use them in moderate
Install a salt guard product to help protect against damage to the concrete surface.
Salt is salt, no matter what chemical name you want to call it.
They all pose a problem when it comes to a concrete surface.
All the above things having been said, I wonder why you even care, unless of course one of the homes belongs to you.
Just report and move on, if you feel it is significant. I would consider the issue cosmetic only.
None of my business what the builder and home owner do, or not do.
Reactive aggregate can also cause problems, although it’s usually visible as popouts directly above aggregate that have very little concrete cover. Popouts are usually little sloped-sided craters about the same size as the aggregate (often ¾" to 1") and scaling is usually wider, thinner sections (more like a scale!). A photo would help.