Concrete sidewalk crack repair

[trader_4]

Any experience with concrete crack repair products? I have a concrete sidewalk that's cracked completely across. Actual crack width across the whole thing is about 1/4", but it has some area where at the top some 1.5" wide areas have spawled and chipped out. It cracked due to settling. Plan is to dig out on the sides, jack it back up, put some concrete under it to keep it raised. Question is what to use to fill the crack? I'm thinking one of the products for concrete repair would be better than mortar. I think they have additives that make it more flexible and less likely to crack than mortar? Another issue is the sidewalk is aged, so I guess whatever goes in won't match perfectly. You'd think they would have some product to come closer to old concrete, but I've never seen such a thing. Anyone have any recommendations of specific products?

[Ed Pawlowski]

I've never seen a really good patch. When I lived in Philadelphia, every block had a sidewalk and ours was built about 1949. By the 1970's there was cracking and breaking. There was a cement guy that would contact everyone on the street and do all the fixes at the same time. One day the individual block was taken out, next day they would all be poured. Don't recall the price, but very cheap.

If you live in a neighborhood that had enough work to be done, you may be able to get it replaced at reasonable cost.

[Tekkie®]

trader_4 posted for all of us...

I got this when I searched. I never had to do this so I defer to others.

One idea is to saw the bad part out and repour the concrete. May save some work, but then again?

&client=firefox-b-1

[trader_4]

I had considered that, re-pouring the one section. I could cut it off at the two control joints or whatever those slots are called that go across to give it a place to crack. Of course it cracked ten inches away instead. But I was hoping to do the more limited, easier repair. Cutting the concrete doesn't sound like much fun. Also, IDK how it will look with one new section, in the middle of the old. Either way it will be noticeable. If the crack repair doesn't last, I always have the other option later.

[gfretwell]

Nothing really makes the repair disappear. If you have a bad base under the concrete it is always going to crack. Down here they just say it is always going to crack. ;-) The bigger piece you take out, the more base you fix, the more stable it will be. I would at least do a 3-4' piece. One problem you have is, in spite of the rumors, sack mix is actually stronger, 3000-3500 psi, (more portland) than the typical 2500 psi they use for sidewalks so it will cure darker. You could get closer to the color if you mixed in some light color sand. Prepping the base will involve using sand and gravel under it, compacted. They actually sell "base material" that is a plant mixed combination of different grades of material. Compaction is still the most important part. The compactor I use is a short piece of piling with a handle on it. Just work your way around the area picking it up and dropping it. It is a good workout.

[trader_4]

If I decided to pour a new piece, the only problem there is cutting the existing off from what's there. This sidewalk was poured with just those indentation grooves that they make with a tool as it's setting, that is supposed to provide it with an easier place to crack and break if it's going to do that. There were no complete gaps where that asphalt material or whatever goes to provide for movement. Of course it broke 6 inches from one of those groves, not along it. So, I'd have to separate it at two of those control grooves. I see there are some other ones along the length of the sidewalk where it has cracked perfectly along the groove as intended. So, how would I separate it?

I guess I could go rent a concrete saw. I've seen blades for circular saws that will cut concrete, is that doable and how hard is is it? I guess another option would be to try to bust the cracked section up, trying to get it to break clean along the indentation. Guess if I went the replacement route, I could try that and if it fails and I crack the next one, I can still do the sawing off option, replace two sections instead of one. Each section is maybe 6 ft or so, I think. All this is why I'm leaning towards using a patch material first and seeing how that works out. For $5 I wouldn't have only that and a little time to lose.