My garage area, which is currently just a concrete slab for parking cars on, has a natural spring that pops up just at ground level. The water never stops, and the concrete there is permanently wet all over. Im hoping to create a channel so that the water is funnelled around the sides of the concrete base, and later into a pond area set below the concrete. My problem is how to fix some kind of guiding masonry such as a row of bricks, onto the floor in a way that will be totally waterproof - but which will also fix to the floor, which will be wet during the process. Is there a concrete or similar material which will glue itself onto a very wet concrete base? Failing that, any other ideas for how to create a channel that will send this water around the sides of my concrete base, and not leave it covered all over? Any help appreciated.
You want hydraulic concrete.
Hydraulic concrete is a concrete that will bond to other surfaces when wet, and cure when wet. It can even be used underwater.
This page will give some guidance on how to apply.
Given the nature of hydraulic cement I'm thinking that your best bet is - in a dry place, build something that you can put in place to divert the water. Test it by "dry" (haha) fitting it against the spring (if thats the word), and once you're satisfied that it will divert the water properly once sealed, clean the wet space (Pressure washer, lose the moss and stuff) then seal in your diverter system with the hydraulic cement.
Portland cement, the active ingredient in concrete and one of the active ingredients in cement/sand blends that masons use to lay bricks and more, will cure in the presence of water, even if completely submerged.
It will not “glue” to itself. Any bond that concrete has with a neighboring material (even more concrete) is purely mechanical.
If you are going to cast in place a concrete channel or curb to divert water, I would recommend drilling some holes in the existing slab, setting rebar into them with epoxy, and wire-tying to these vertical pieces of rebar some more pieces that will run horizontally inside the length of your casting.
If you are going to lay brick, I recommend roughing up the surface of the slab really well in the area you intend to lay on with a hammer. You have to take some chips out of the surface and expose some raw and rough concrete that the cement can bond to. The more the better.
You can’t STOP the water, you can only CONTROL it.
You have water coming in from all sorts of places: 1) from above grade embankment, 2) from surface water, and 3) from sub-surface water.
I recommend you install a 4” rigid (don’t use the coiled perf pipe) perf pipe drain around the perimeter of your garage and on top of your existing slab. Then install a 6” layer of round drainrock (3/4”-1 1/2”) completely across the entire slab and encase the perf pipe. Then install a new 6” reinforced concrete slab on top of the drainrock and drainpipe. The perf pipe should be extended away from your garage using a 4” SOLID rigid pipe to a drainage swale.
The perf pipe and drainrock will collect any moisture coming from above or below the slab. Your new slab and garage will remain dry. (Btw, don’t connect any roof drains into this pipe. You don’t want a heavy storm to backup under your slab.)