Pond Boss Forums POND CONSTRUCTION Building a dam Crack in concrete dam

That crack will transfer thru the 2" cap relatively quickly. If you don't mechanically and chemically treat the dam before applying the new layer of concrete, it won't adhere to it (for very long).

Unfortunately, the only other fix that I can think of is this one:

Mechanically cut out the crack. Find out why the crack happened, and properly compact the soil so it doesn't happen again. Clean and mechanically roughen the cut surfaces. Drill holes in the existing concrete, and epoxy "coated" rebar into both sides. That's the green rebar that you see them using on roads and bridges. Tie them both together. Coat both sides of the cut areas with a bonding agent, and pour new concrete in the cut-out area.

I like using both steel for a structural aspect, be it rebar or mesh, and the fibered concrete to help control surface cracks. Overkill? Maybe; but the jobs that we did (and spec'ed out that way) didn't crack.