New Build Paving Slabs

[EmzehC]

Hello,

I am hoping to gain some expert opinions on the paving slabs which have been installed to the front and rear of my new build property.

As you will see from the images below, the slabs have some very dark markings present, which are also present on a number of other properties within the development. I have mentioned this to the developer and they have stated that in the groundworker's opinion its due to the fact that the cement still has water sitting in between. Is there any truth in this, or has this been caused by a manufacturing issue/the installation process?

https://photos.google.com/photo/AF1QipP ... QXpevp09zy
https://photos.google.com/photo/AF1QipN ... tZRR8YwCr0

Any thoughts or opinions are very welcome.

Thanks in advance.

[Tony McC]

As posted elsewhere, these links are invalid - can you provide live, working links?