Recycled Concrete

Concrete is often used for non-structural fill, road base aggregate, or for specific landscaping projects. In some cases it is more cost effective to recycle a concrete building by crushing it onsite and use the crushed material for the new project. The use of recycled concrete significantly reduces unnecessary material being sent to the landfill.

Potential dangers to consider

  • Respiratory – Silica dust, if not kept wet can pose a serious risk to the lungs of construction workers if respirators are not in use when recycled concrete is being delivered, moved, or its fine dust is being blown around.
  • Other potential hazards – Unless stringent testing has taken place, including a phase II environmental site assessment, lead-based paint and asbestos can periodically be found in recycled concrete. Be sure the source of recycled concrete has followed proper protocol for testing and inspections before accepting delivery to the jobsite.
  • Stormwater management– The run-off from large piles of non-washed, recycled concrete can contain toxic metals, be caustic and corrosive, having a pH near 12. In comparison, Drano liquid drain cleaner has a pH of 13.5. The safe pH ranges for aquatic life habitats are 6.5 – 9 for freshwater.
  • Respiratory Protection – If recycled concrete material can’t be kept wet, then respiratory protection should be worn by any employees that will be working around it while dust is being generated.
  • Material Handling – Safe to the touch, the primary hazard of concern is the dust generated when handling the recycled concrete material, unless it was already pre-washed.
  • Air Quality – In some cases, air quality monitoring may be required to ensure protection of the construction workers and to provide documentation that proper safety protocol was implemented.

Presenter Tips

  • Pre-read the Tool Box Talk. Your comfort level and confidence will be higher if you know your topic.
  • Discuss related tasks, work areas or events that make the Tool Box Talk relevant to your jobsite.
  • Involve the workers by asking questions and input that drives discussion. Funding and support for this project has been provided by the State of Washington, Department of Labor & Industries.

Questions for Discussion:

  • Why is it important to worker safety? Which trades need to participate?
  • Who is responsible for oversight?
  • What equipment & materials are involved? How is it communicated & monitored?
  • How is it measured & reported?