Using Roadware 10 Minute Concrete Mender.
Remove loose material and create a shelf on both sides of the joint with a minimum profile of 1.5” deep and 2” wide on each side. Vacuum and thoroughly remove dust and contaminates.
Create a repair base by filling repair area halfway to grade with bulk mixed 10 Minute Concrete Mender™ combined with 10-20 grit silica sand.
Use a ratio of 1 Part mixed Concrete Mender to 2 parts silica sand. Up to 1/2 part additional sand may be added during application to assist with troweling and placement. Be sure to leave the lower half surface rough and sand covered to accept the next layer.
EXAMPLE
1 Qt side A,
1 Qt Side B,
4 Qts 10-20 silica sand,
Up to 1 quart additional sand as needed.
Once the first layer sets and turns grey, continue with an additional layer up to flush with the surface.
The mixed material should always be resin rich and the sand should be fully saturated when applying to the repair area.
For extra surface strength, 30 grit aluminum oxide may be broadcast and troweled in place on top as the materials start to gel in about 5 minutes after placement. Allow to fully cure and grind flush within 24 hours. OPTIONAL: Re-saw the contraction join
You mention using a silica sand mix for the repair base. Are there specific size gradations of sand recommended for optimal results with the 10 Minute Concrete Mender?
For consistency, we use and specify 40-30 grit silica sand for testing and base applications. Sand gradations from 15 mesh to 70 mesh will also be very effective. Industrial quartz, colored quartz and many sand blasting sands will work as well. The color of the sand does effect the color of the final repair.