A sliding gate needs a track for the wheels as the gate opens and closes. Otherwise, the gate would go out of square and get jammed and could not be opened and closed. The gate rail is a piece of angle steel welded to a piece of flat-plate steel that the wheels run along. Before installing the gate rail to the concrete, a suitable primer should be applied to the bottom of the rail to keep it from rusting.
Place the sliding gate rail in place and check that it is in the correct position. Mark the gate rail location on the concrete so that it can be put back in the correct location.
Drill through the flat steel plate of the gate rail about 16 inches apart along the rail's length. Use a steel drill bit that's the correct size for your concrete anchors. The gate rail will take a lot of abuse from cars driving over it, so use 5/8-inch concrete sleeves at a minimum.
Place the steel gate rail back into position on the concrete. Mark the location of each hole where the gate rail will be anchored to the concrete. Use a black permanent marker to indicate the inside of the hole onto the concrete.
Prepare a concrete drill bit for the size anchor you are using into a hammer drill. Place a piece of painter's tape on the drill bit to indicate the depth needed to secure the anchor. This should be the length of the concrete anchor and the thickness of the steel plate plus an additional 3/8 inch.
Drill the holes for the concrete anchor with the hammer drill. Keep the drill bit running straight as you drill. Blow out the holes of any concrete dust after you have drilled all the holes. Use a can of compressed air for this.
Tap the concrete anchors into the holes you drilled into the concrete. Check that the anchors are in the right direction.
Secure the gate rail to the concrete, using a socket wrench to tighten the bolt and lock washers down to the concrete anchors.