I had to fix some old concrete steps that had a bunch of cracks in it. What we did is just pour a 1 inch layer of concrete over the top of the steps and top landing. The top landing is about 4 x 8 feet. It rained a bit the night after we did the top landing and in the morning it had some patches that are a little whitish, and the concrete is not hard. If you rub it with your hand you can rub some of it away. I am hoping it will harden. Any idea if it will harden, or what could be done to harden it?

It was suggested we could try and seal the top with concrete sealer.

Thanks

Peter

Anti-Hydro is what was used years ago. May be something different avail now. Did you use a concrete plaster adhesive to halp adhere it to the original step?

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Terry Allison
N. Calif. & Boca Chica, Panama

09' E320 Bluetec 77k (USA)
09' Hyundai Santa Fe Diesel 48k (S.A.)

Concrete cures slowly and should be watered during the curing process for attainment of ultimate strength.

Give it two weeks and check it again.........but, keep watering it........

A one inch layer on top of old concrete doesn't sound good to me. I hope it works out but I'd be afraid the bond between the old and new would not be very strong and the one inch layer would fail, particularly in your climate. Anyone had experience with this?

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1977 300d 70k--sold 08
1985 300TD 185k+
1984 307d 126k--sold 8/03
1985 409d 65k--sold 06
1984 300SD 315k--daughter's car
1979 300SD 122k--sold 2/11
1999 Fuso FG Expedition Camper
1993 GMC Sierra 6.5 TD 4x4
1982 Bluebird Wanderlodge CAT 3208--Sold 2/13

Water is good for concrete UNLESS it was a hard rain so that it actually displaced some of the cement and raised the water:cement ratio. ( We actually cure concrete test cylinders under water so that we get the maximum strength of which the batch is capable.)
Based on your description my guess is that the rain had a detrimental effect on the concrete.
As Brian suggested, wait a week or two and see what its like. You may have to chip off the patch and redo the topping again.

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1982 300SD " Wotan" ..On the road as of Jan 8, 2007 with Historic Tags

We used a bonding agent to help it adhere to the concrete below.

I know a thin cap was not the best solution, but the tenant was getting pissed off at the ugly steps and we had trouble finding a pro to do the job. I can't believe people were turning down a several thousand dollar job for what took 2 amatuers one day to finish. We used 100 bucks in concrete. We would be happy if it holds up to next summer when we can try and find someone to do it right. I imagine if the economy slows more it will be easy to get it done then. We need to keep tenants happy in these times.

We will give it a few weeks and see what happens. I guess if it still does not harden, we could always just put a skim coat of "Top n bond" over it.

If you do it again, try a topping or self leveling compound (Ardex) rather than a concrete mix. They are loaded with additives, fibers for strength, are fast setting and have products meant for the depth you need to skim. Make certain it is not gypsum based.

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Terry Allison
N. Calif. & Boca Chica, Panama

09' E320 Bluetec 77k (USA)
09' Hyundai Santa Fe Diesel 48k (S.A.)

Concrete "cures" (not drys) with the hydration of the portland cement. It will (should) be very hard in 28 days and will slowly continue to harden for years.

Keep it damp and give it time.

The white stuff will brush off.

SIKA makes Concrete Repir materials that are far better than Ardex, which is a Floor Underlayment AKAIK (ref: Ardex Catalogue in front of me)...

SIKA 331 Is what we use to repair Concrete Honeycomb and spalled areas when formwork is removed or a spalled area arger than 12"x12" is found.
I think it's around 6500 PSI when it cures.

As long as you used a decent concrete bond agent, like Weldcrete, it should be ok.

Just lay some canvas or burlap over it and keep it soaked for a week and it will set just fine.

The white patches is likely chloride from the concrete mixture once it's cured it will wash away.

That SIKA sounds good. I will look into that.

Thanks

Peter

I'll be impressed if a 1" cap stays on through freeze thaw cycles and summer heat.

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[SIGPIC] Diesel loving autocrossing grandpa Architect. 08 Dodge 3/4 ton with Cummins & six speed; I have had about 35 benzes. I have a 39 Studebaker Coupe Express pickup in which I have had installed a 617 turbo and a five speed manual.[SIGPIC]

..I also have a 427 Cobra replica with an aluminum chassis.