The police have used sledgehammers to smash through the doors of residences or other buildings. Even if obstacles are placed behind the door to fortify it, the sledgehammer will eventually break through, which was clearly demonstrated in South Korea in 2009, when a group of Korean congressmen barricaded themselves within a room to hold a vote, and an opposing faction used a sledgehammer to break the door down.
Sledgehammers are ideal for driving stakes into the ground and concrete. In the past sledgehammers were always used when laying railroad tracks because they were the only tool with enough force to drive stakes into virtually any kind of terrain. Sledgehammers are also useful for driving posts into the ground when setting up a large tent.
Knocking down walls is another use for sledgehammers. Concrete walls require more time and energy than walls made of drywall or plaster, but regardless of the wall's composition, a sledgehammer will eventually tear it down. This tool is indispensable if you want to make a room in your house bigger or if you want to add another room to your house. Whether you have an interior wall or an exterior wall you want to remove, sledgehammers are the tool of choice.
If you need to remove concrete slabs from a sidewalk or a driveway, you will need to break them into smaller pieces first, which can be accomplished with a pneumatic hammer, but this is a costly measure. Using a sledgehammer is a much cheaper way to accomplish the job. The project may take a lot of strength and time, depending on how much concrete needs to be removed, but eventually you will break the slabs into pieces small enough to carry away.