Patch between two slabs?

[Spahrman5]

The pictures below show what I am dealing with. The previous owner built a second bay onto the garage but left the center wall confused. I removed the wall and would like to fill in the trench. It measures 3 1/2" wide, 19 ft long, ~5" deep, and is directly on top of the old exterior foundation blocks.

After having various concrete contractors look at it, I was told to just fill it with conrete and trowel it smooth. I'm getting mixed answers about whether I need to keep the black expansion material on the side of the trench as it is currently.

What would you guys do? Any advice on how to procede would be appreciated.

 

[Kevin54]

That is exactly the same thing I dealt with. When I built my garage years ago I had a foundation put in for a wall. Last year I believe, I took the wall out and had to fill in between. It was filled with concrete and troweled smooth. But the problem I face is that when the floors were poured, they were fine with a wall, but without the wall I have maybe a 1/2" to 3/4" variance between the two floors. I would like to have it smooth without the slope, but I think I will end up having to tear out some concrete to get there.

And as far as holding up, mine is not pinned and it hasn't cracked at all in the patch. No expansion joint either. Just mixed up bags of Sakrete and poured.

 

[Spahrman5]

Thanks Kevin, I just wanted to make sure I wasn't over simplifying it.

About your issue, I also have a slight variance between the two floors. However they are only off by about 1/4-1/2 inch at most. I will probably have a slight slope as well. After the patch, I am diamond grinding, so I'm hoping I can feather in the slope so it is not as noticeable.

 

[JimVonBaden]

IMHO Expect the joints to crack slightly as the slabs heat and contract. I wouldn't put anything in between them, but I would trowel a line on each side, then fill it in with a flexable expansion seal after the concrete cures.

Jim

 

[Kevin54]

I don't have score lines in mine and the joints are tight.

What you may want to do though is wet down the sides a little bit to help the concrete bond. I though I had pics on my computer but they must be on my other computer. As soon as I find them, I'll post them up

 

[JimVonBaden]

I don't have score lines in mine and the joints are tight.

What you may want to do though is wet down the sides a little bit to help the concrete bond. I though I had pics on my computer but they must be on my other computer. As soon as I find them, I'll post them up

Kevin,

How old is yours? Do the two pads otherwise touch anywhere, or are connected?

Generally when two seperate pads, especially poured at different times, are connected, small movement happens and the pads will show a crack line along the joint.

Jim

 

[Kevin C]

You might want to consider putting a single piece of rebar down the middle to reduce the chance of getting a crack in your patch (across the patch).

Kevin