Before replacing the concrete, try removing the stain:
1. first try a gunite rust eraser, found at pool supply places (the tan ones, not the black ones)
2. if that doesn't work, buy a bottle of 1000 mg vitamin c tablets, CRUSH them up, put them in an old nylon stocking tied up in a ball/pouch nice and tight (20 tablets per nylon pouch), soak it in a cup of water for 5 minutes, and place it on the stain. Leave it there for 2 hours, and every 15 minutes check it and drizzle a 1 oz shot of water on it. When the stain is gone, hose off the concrete. The concrete may clean up cleaner than the surrounding concrete, so check it often.
If you do replace it, seal it. It may still rust, but it will be slightly easier to remove with the above methods. Strict prevention involves strict maintenance on the coating.
1. first try a gunite rust eraser, found at pool supply places (the tan ones, not the black ones)
2. if that doesn't work, buy a bottle of 1000 mg vitamin c tablets, CRUSH them up, put them in an old nylon stocking tied up in a ball/pouch nice and tight (20 tablets per nylon pouch), soak it in a cup of water for 5 minutes, and place it on the stain. Leave it there for 2 hours, and every 15 minutes check it and drizzle a 1 oz shot of water on it. When the stain is gone, hose off the concrete. The concrete may clean up cleaner than the surrounding concrete, so check it often.
If you do replace it, seal it. It may still rust, but it will be slightly easier to remove with the above methods. Strict prevention involves strict maintenance on the coating.
