I need to anchor a shed to cement or concrete with ⅜" x 3" anchor bolts. I have a Bosch "long life in concrete" ⅜" bit. The drill motor is medium-size but was able to get three holes deep enough (three inches) without great difficulty, and one is almost there. But the fifth one is only two inches, and it seems that it just won't go any further. (More than a minute with much of my weight pushing down on the drill.) The bit does not appear to be worn out. Putting a punch in the hole and beating on it with a sixteen-ounce hammer doesn't seem to make a difference.
Does this mean I've gone through the cement and encountered a particularly hard rock? Or what might it mean? A solution?
UPDATE: Whatever was interfering suddenly surrendered and it took less then fifteen seconds to do the rest of the hole. So it was probably a rock that moved out of the way. Rebar is embedded in the cement and would not have moved.