At the end of any construction project, there's bound to be a large amount of debris. But what looks like disposable material could turn into a money and time saving opportunity. Leftover concrete is a valuable source of material, often used as a subbase layer for other projects. Because recycling concrete can cost as much as $100 a ton, reusing old slabs is not only a greener alternative, it can help you source building material at a lower price. Putting old building material to work only takes a few steps.
Things You'll Need
12 lb. sledgehammer
Electric jackhammer (optional)
Pry bar or mattock
For a Path
Cover the concrete slab with a plastic tarp to avoid flying pieces. Break up existing concrete into smaller pieces that are easier for you to handle. Use a 12 lb. sledgehammer for slabs no thicker than 4 inches. For larger pieces, rent an electric jackhammer, which will make your job a lot easier, physically. Use a pry bar or mattock to help you lift and separate the pieces.
Select the stones that you want. Laying a walking path in your yard or garden is the perfect way to reuse old concrete and doesn't require mortar. Select the size stones you want and arrange them in an interlocking pattern to make sure they fit. You may need to do additional chiseling.
Lay down a layer of sand along the path, 1/2 inch lower than the thickness of the stones, and carefully lay out the concrete pieces in your pattern.
In New Concrete Mix
Take the used concrete slabs to a concrete processing site.
Workers will remove contaminates, such as steel and soil, from the concrete, then pulverize it and prepare it so it can be added to a concrete mix.
Add the recycled concrete to the base when mixing concrete for projects. Recycled concrete has a higher water absorption than new concrete and will require 15 percent more water than you normally use.
If your soil is prone to erosion, you need to add a layer of gravel under the sand. Rent a power tamper to help you compact the gravel. There should never be more than 10 percent of contaminants in RCA.