How to repair small patch in exposed aggregate concrete?

Atul

Hi team,

I want to fix the patch that was shared in the picture. This is the surface of expose concrete which had damaged. Can you please advise which cement require with same pebble stone I assume the patch is not big. So we require small amount of material

JacobZ

Hi @Atul,

It looks like you have exposed aggregate concrete, but fortunately the area you need to repair is very small.

I'd start by tidying up the damaged area, removing any loose or crumbling material and giving it a good brush out so you're working with a clean, solid surface. You can then apply some BondCrete to the inside of the repair to help the new material bond to the existing concrete.

Once that's ready, I'd fill the area with a small amount of mortar, pressing it firmly into the repair and bringing it up to the surrounding level.

Allow the mortar to firm up a little, then gently wipe the surface with a damp sponge. This will help smooth and blend the repair while also removing a small amount of the cement paste from the surface, which should help expose some of the existing aggregate around the edges and make the patch less noticeable.

Concrete is comprised of sand, cement and aggregate and mortar is sand and cement without the aggregate, so you're essentially just adding back the missing mortar between the aggregate. I wouldn't worry about trying to add aggregate. The repair is simply too small to realistically recreate the original exposed aggregate finish, and adding stones would make such a small patch unnecessarily difficult to work with.

The colour of the new mortar is unlikely to be a perfect match initially, but it should become less noticeable as it weathers.

Let me know what you think and if you have further questions, please don't hesitate to ask.

Jacob