To solve that pesky little problem, I developed a technique that works great for nailing binder, or flat, bar to concrete floors. You will need a hammer drill; 1/8-inch masonry bit; binder bar; nails, of course; and round toothpicks.
Remove the metal, and finish drilling the holes to the depth needed to accommodate the drive nails (usually 1¼ to1½ inches). Position two round toothpicks together and, using a hammer, tap them all the way into the hole (photo 3). There will be approximately one inch of excess toothpick remaining; just snap it off even with the floor. Replace the metal and secure it tightly with drive nails(photo 4) or properly colored screws.
Let me leave you with a quick tip: If you run out of silver nails, just sand off the tips of the gold ones. They’re silver under the gold finish.