Calcium is the gift that keeps on giving
If you run pH and TA at the low end of the scale so that the CSI is negative, and you brush it frequently with a steel brush, you can dissolve some of it back into solution. Think glacial pace. Months if not years. If it's really bad, people will get road rash just brushing against it. It can get like 60 grit sandpaper. If it's mild, it actually improves traction.