Which concrete patch?

[theonlynamenottaken]

I've got a very unique structure that has a semi-circular cross-section slab that goes from vertical (wall) to horizontal (floor) with a radius of curvature ~30'. In order to cast it forms were placed on top and shotcrete was applied from below (wet mix, 4000 psi, fiber reinf, fly ash, 3/8" and smaller agg). The shotcrete contractor did a lousy job and there are voids everywhere on the top surface. Structurally the slab is fine but aesthetically its horrible. I need a high quality patch that can be applied on vertical wall surfaces and on horizontal floor surfaces from full depth (3.5") to featheredge.

Any suggestions? I just don't want to spec something that is: A) Too expensive (non-profit client), B) that will chip out after a couple of freeze/thaws, C) that needs several different patch types for vert, horz, deep repairs, featheredge repairs.

 

[GeoPaveTraffic]

Here are a couple of CONSPEC products that we have had fair to good results with on street projects.

Pave Patch 3000
Conpatch V/O

Every product that I've seen has a minimum patch depth, i.e. none are recommended for "featheredge" repairs.

 

[Ron]

t-o-n-n-t...GPT makes a good point...don't featheredge a repair.

You mentioned freeze-thaw. This exacerbates the issue a bit. The two materials mentioned by GPT are good. You might consider Sika products as well (SikaTop 123 or similar).

Surface preparation will be a key to success, as will pinning the patch to the existing concrete. With the thickness range you are discussing, the "overlay" should be pinned to the existing concrete using epoxy-set rebar. If you create a substantial pinning grid, you could also re-shoot the surface with shotcrete, provided the existing surface is well prepared (highly roughened) and a bonding agent is used.