Learn How and Where to Recycle and Reuse Concrete

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••• Photo by Zappowbang

Concrete can be recycled and reused in many ways. The best method often depends on the size and shape of the concrete to be recycled. Reusing concrete is a good way to reduce construction costs while providing some benefits to the environment. Recycled concrete not only stays out of the landfill, it also replaces other materials, such as gravel, that must be mined and transported for use.

Uses for Old Concrete

Recycled concrete can be used in many of the same ways as new materials, like gravel, paving materials, and aggregates.

  • Paving for walkways, driveways, and other outdoor hard surfaces. Broken concrete creates a stable traffic surface that is permeable so that rainwater can filter through. This reduces the amount of runoff water that must be managed by storm sewer systems and helps to replenish groundwater.
  • Base for new asphalt paving. Through a process called rubblization, old concrete pavement can be broken in place and used as a base layer for asphalt pavement
  • Bed foundation material for trenches containing underground utility lines.
  • Aggregate for mixing new concrete. Crushed recycled concrete can replace some of the virgin (new) aggregate used in ready mix concrete.
  • Material for building new oceanic reef habitats.
  • Paving blocks, pots, and benches for community use.

Benefits of Concrete Recycling

Recycling concrete helps reduce construction waste and extend the life of landfills as well as saving builders disposal or tipping fees. It also reduces transportation costs because concrete can often be recycled in areas near the demolition or construction site. If builders are seeking LEED Green Building certification, they can receive points for using recycled concrete. In some instances, employment opportunities arise in the recycling industry that would not otherwise exist in other sectors.

How Concrete Is Recycled

Concrete is recycled by using industrial crushing equipment with jaws and large impactors. After the concrete is broken up, it is usually run through a secondary impactor and then is screened to remove dirt and particles and to separate the large and small aggregate. Additional processes, such as water flotation, separators, and magnets may also be used to remove specific elements from the concrete. An alternative method is to pulverize the concrete, but this is not the always the best option, as it makes it harder to complete the separation process and may leave more contamination from smaller byproducts.

Equipment Used to Recycle Concrete

When considering the option to recycle concrete, you will also need to evaluate the options available to crush the concrete. The most practical solution can be a portable crusher that can be moved to different locations or projects. Often it works best to set it up a portable crusher at a centralized location, near where the concrete is being demolished but in an area that will not impact site traffic. Factors to consider when choosing processing equipment include:

  • Equipment should have a powerful electromagnet or water flotation or an air separator system that can pull steel from concrete.
  • Separate hydraulic stands allow for a faster setup.
  • Control systems may be automatic, manual, or remote.
  • Systems with conveyors, jaws, and cones can provide complete processing of the concrete from demolition to a usable material.