Cleaning concrete is easy and inexpensive. If you know how to clean concrete, you can restore an unsightly driveway in no time. Cars don’t have to be very old before they start leaving oil and grease stains on the garage floor and driveway. This method will remove most stains.
You'll need a 5 percent solution of muriatic acid, which is available at hardware and home improvement stores. You'll also need a broom (use an old one because you'll need to throw it away after) and a garden hose.
Pour muriatic acid solution onto the grease and oil stains.
The muriatic acid eats up oil and grease and produces unpleasant odors; so, be sure to keep the area well ventilated.
Wear safety glasses and long sleeves, long pants, and gloves any time you’re working with acids! If you have lung problems, get a helper so that you can cut down on the amount of time you’re inhaling fumes, or have someone else do the job.
Scrub the stains.
Use the old broom to scrub the stains.
Rinse the pavement with plenty of water from the garden hose.
You may want to rent a high-pressure hose. As the acidic water flushes out of the garage, it will clean up the rest of the floor.)