The Dangers of Asbestos in Concrete and Cement
From the early 1900s through the 1970s, asbestos was used in many building materials as a cheap, readily available way to add insulation, fire resistance, and reinforcement. Following the discovery of its health risks, a variety of asbestos-containing materials (ACMs) were banned between 1973 and 1979. But due to its low risk to the general public, asbestos-containing concrete (or asbestos concrete) remains legal to manufacture, import, and use in new construction. Exposure risk is low when the concrete is set and undisturbed, but any mechanical damage can and will release asbestos fiber into the immediate environment. As such, it poses a particular safety threat to those in the construction industry when proper precautions aren't taken. Below, we'll review why asbestos cement was useful, where construction crews are likely to encounter it today, and the conditions under which the Occupational Safety and Health Administration (OSHA) requires extra safety measures.
Uses and Benefits of Asbestos in ConcreteThe fiber-reinforcement of concrete is a common practice that incorporates a wide variety of fibrous materials into concrete mixtures. Since the fibers are randomly oriented but uniformly distributed throughout the concrete, they increase its structural integrity. Generally speaking, fiber reinforcement is used to:
- Increase the tensile strength
- Control cracking from plastic shrinkage and drying shrinkage
- Lower the permeability of the concrete to reduce water seepage
- It easily blended into concrete mixes, whereas other fibers can make concrete less workable.
- It was resistant to corrosion, unlike other fibers that cause corrosion stains at the surface.
- It had low friction. This made it particularly attractive for cement piping.
- Its superior strength-for-weight ratio made it a go-to roofing material to replace slate or clay.