Outdoor Patio/Paver Joints

[TC 83]

Seeing anyone had some suggestions/advice for these pictures? The material that was used for these joints I cannot find and I don’t even know what it is...It’s pretty flexible and pretty thin. I’ve tried using foam rod to fill and then caulk but it just doesn’t look right. The joints are about 3/4”. Any suggestions? Would polysand work?

 

[DancingOutlaw]

I don’t see why poly sand wouldn’t work.

 

[eskimovol]

It's an epoxy most likely.