I did some plumbing in my basement by jack hammering up the floor to install a drain for the shower and sink.

I back filled the trench partially with gravel and poured new concrete. The trench was 15" wide by 4" deep and about eight feet in length. It's been 3 weeks now and the concrete won't dry.

Any suggestions? Does anyone know what to do and why it won't dry?

First off concrete does not dry- it cures.

Second if after 3 weeks it is still not dry then it was not done correctly. You might have needed more cement (glue that holds the concrete together). It sounds like your mixture was to wet to begin with.

Thanks for the lesson. I used Quickcrete ready to use concrete mix and I thought I was VERY conservative on how much water that I used.

Do you have a suggestion on what I should have used that provides the cement that you indicated in your response?

Hi,
I'm not an expert on cement or concrete or anything really, but I had a similar problem with some quickcrete concrete mix. I had two bags and one cured fine the other was still wet a week later. I removed the wet and tried another bag, mixed it the same as before and it was good in a few hours. Possible you got a bad batch?? Missing something? I'm not sure. Just a thought

I have been involved with many thousands of tons of concrete building bridges, roads, sidewalks, light pole foundations, etc etc. I have never heard of concrete not setting after 3 weeks or anything like that. Contractors sometimes have retarders added which delays the chemical reaction, giving them more time to work on bigger pours. Even with way too much water it will usually set within a matter of hours, definitely not weeks. They either left out most of the cement or mistakenly put a chemical retarder into the quickcrete. It is said that adding sugar to fresh concrete will delay set but I've never tried it, and it would be sabotage in your case. Concrete even sets under water.

Try contacting Quikcrete directly and ask them what's wrong? They may replace the product free of charge because I think you'll be digging it out. QUIKRETE® - Contact Us