How to repair concrete basement floor?

Question

I dug up concrete floor to replace a section of corroded cast iron sewer pipe, and have a question about the floor repair. The ground is very wet clay, and the trench around the pipe is about 1 x 6 feet, 12" deep (3" below the pipe). First, should I leave the trench open for a while to dry out the clay? Second, should I just fill the whole trench with concrete - completely surrounding the pipe, or should I put some other fill in first and top it off with concrete?

THANX!

Answer 1

i would buy a small amount of  crusher run, put it in the hole in 4-5in. lifts compacted tightly up to the bottom of the concrete. then cover the crusher run with a plastic sheeting. now drill 1/2 holes around the base of the concrete slab about 10/12in. apart, insert re bar dowels into the existing concrete, finish the fest of the hole with a wire mesh. fill with concrete and finish to your liking.

Answer 2

I would recommend filling the hole with sand, making sure you have it under the pipe (you did use PVC this time right?) and tamped somewhat,  up to about four inches under the top of the rest of the floor.  You can use a two by four to level the new concrete with the existing floor.  Mix up some sakrete or concrete mix and put this on top of the sand to level with the existing floor and finish it to match.  Stay off of it for a few days to let it cure.  If the old floor had wire mesh in it, you may want to put some in the new floor concrete.

Answer 3

I would recommend taking out the clay and replacing it with crush or sand as mentioned above, leaving 3 to 4 inched for concrete. Joining the old crete to the new as mentioned above is also recommended. DO NOT pour concrete around the pipe. You or the next owner will end up with a broken pipe problem.

Good Luck