Crack filling: which sand?

[atlm]

My current plan (subject to change) is to finish my concrete floor with one of the clear solutions: TS210 sealer, or Polyurea with non-skid, or the BallistiX 2-layer system.

I believe my next step is to fill the cracks and cuts in the concrete floor. (Due to location, the concrete had to be pumped so had extra water, which I believe caused the shrinkage cracks. The concrete contractor made 3 cuts the morning after the pour but it still cracked in a few other places.)

After reading this @Shea All Garage Floors article about crack repairs I was going to buy the Simpson Strong-Tie ETIPAC10 - 9oz CRACK-PAC Injection Epoxy. But then I found this XtremeSet-100 Crack&Joint Filler by @LegacyIndustrial which seems like it could be better for the thinner cracks I have.

For either, I believe I need to prefill the cracks with sand. I'd like the sand to be close to the color of the concrete (dark-ish gray) so the cracks aren't obvious through the clear finish. I read I should use silica sand. I found this Sandsational Pewter Unity Sand (22oz) Dark Gray , but the description mentions "subtle sparkle", which might make it stand out.

Which dark-ish gray sand works and is closest to the color of concrete with a clear finish?

Pictures of crack sizes:

 

[Jgaz]

I don’t know about color match when it comes to sand.
I would recommend going with something as dry as possible. Fill the crack to within a 1/4 to 1/2” and use a sikaflex product that closely matches your desired color.

 

[mike93lx]

Why does the sand color matter? Aren't you topping it with a crack filler? The sand is just used to eat up space and provide a backer for that filler

 

[CoRestore]

My current plan (subject to change) is to finish my concrete floor with one of the clear solutions: TS210 sealer, or Polyurea with non-skid, or the BallistiX 2-layer system.

I believe my next step is to fill the cracks and cuts in the concrete floor. (Due to location, the concrete had to be pumped so had extra water, which I believe caused the shrinkage cracks. The concrete contractor made 3 cuts the morning after the pour but it still cracked in a few other places.)

After reading this @Shea All Garage Floors article about crack repairs I was going to buy the Simpson Strong-Tie ETIPAC10 - 9oz CRACK-PAC Injection Epoxy. But then I found this XtremeSet-100 Crack&Joint Filler by @LegacyIndustrial which seems like it could be better for the thinner cracks I have.

For either, I believe I need to prefill the cracks with sand. I'd like the sand to be close to the color of the concrete (dark-ish gray) so the cracks aren't obvious through the clear finish. I read I should use silica sand. I found this Sandsational Pewter Unity Sand (22oz) Dark Gray , but the description mentions "subtle sparkle", which might make it stand out.

Which dark-ish gray sand works and is closest to the color of concrete with a clear finish?

Pictures of crack sizes:

Use Metzger / McGuire joint filler. RS88 they have color options, or Hi-Tech Polyurea on the joints. On the cracks I would use crack fill, use some concrete dust if you are grinding it first, then mix it into the crack filler and fill / Grind off.

Metzger/ McGuire, Joint Filler, RS88​

 

[FJ4FUN]

Any kiln dried sand will do just stay away from "play ground" sand. Most big box stores will have it as "Paver Sand".

 

[ConCretin]

I used Legacy's Xtreme Set with excellent results but it will be tough to get a color match if you aren't coating the floor. For those who don't know, Xtreme Set is a high viscosity liquid that penetrates extremely well to 'glue' the concrete together rather than a typical sealant or filler.

I enlarged the shrinkage cracks with a crack chaser disc in a grinder. After a thorough cleaning, I primed the joint by filling the crack with Xtreme Set in a squeeze bottle letting it seep in, I quickly filled the joint slightly proud with sand and then thoroughly saturated the sand with more liquid. The liquid will overflow and run out slightly so you'll need to 'sand' the surface flush again. If doesn't require heavy grinding but you will change the appearance of the existing concrete slightly.

I used it under Hellfire, which goes on pretty thin and the repairs are literally invisible but I think you'll see them under a clear sealer even if you color match the sand.

 

[atlm]

Why does the sand color matter? Aren't you topping it with a crack filler? The sand is just used to eat up space and provide a backer for that filler

Watch this video starting at the 1 minute mark:

The 2 products I mentioned go down almost as thin as water, and mix with the sand that's poured beforehand in the cracks, flush to the top surface.

I'm looking at thin products that will easily fill the thin cracks, rather than opening up all the cracks wider with a grinder.

I don't need an exact color match, but I don't want the cracks to stand out, either. I believe slightly darker would be less obvious than lighter.

At least that's the way I understand it from watching videos & reading.

 

[Sumboodie]

Sand?

Flexible caulking. The sand will jack the crack apart more if the slab moves.

The slab even solid grey is easier to find stuff, and would help "hide" cracks and other defecrs.

but it's yours so whatever makes you happy (and I don't mean that in a rude wsy)

 

[atlm]

Use Metzger / McGuire joint filler. RS88 they have color options, or Hi-Tech Polyurea on the joints.

Thanks @CoRestore . Is the RS88 thin enough for the thin think cracks, or would I need to open them all up wider?

On the cracks I would use crack fill.

Which crack fill?

use some concrete dust if you are grinding it first, then mix it into the crack filler and fill / Grind off.

I was planning to fill all of the cracks first and then grind, rather than grinding and then filling cracks and then grinding again.