Supplementary Cementitious Materials reduce carbon emissions and add strength to our concrete
IMI commonly uses Supplementary Cementitious Materials (SCMs), or Pozzolans, in place of Portland Cement in our concrete mixes. The most common post-industrial waste products used are Fly Ash, Slag and Silica Fume (a.k.a. micro-silica.) All three of these materials would end up in landfills if not used in concrete. Beyond recycling these waste products, each one significantly reduces the amount of Portland Cement we use in our mixes. This means less mining of virgin materials and saves the energy used to produce it. For more information, click here.

		Fly Ash is a byproduct of coal combustion when used for the generation of electricity. In 3 years, IMI has recycled 480,000 tons of Fly Ash. Slag is a byproduct of steel production that forms when iron ore is melted to liquid form. In the past 3 years, IMI has saved 111,000 tons of slag that would have been dumped.
Silica Fume is a waste material from the production of silicon and ferrosilicon alloys commonly used in microchips. Since 2006, IMI has recycled 9,000 tons of micro-silica dust that would otherwise have been sent to the landfill.

In the past year we've saved 200,000 tons of waste from the landfill, recycled in our concrete, and reduced carbon dioxide emissions by 400 million pounds

What do SCMs do to enhance my concrete?
Concrete is a mixture of stone or gravel, sand, water and Portland Cement. IMI purchases these raw materials and mixes them at our concrete plants. The aggregates involved in concrete production take little energy to prepare for use in our plants. However, Portland Cement is produced by heating limestone in a kiln to form clincker, grinding it into a powder and mixing it with gypsum. SCMs reduce the amount of Portland Cement we use in our concrete mixes.

Silica fume is used to make concrete more impervious, so chemicals that would normally penetrate the concrete and weaken reinforcement (such as chlorides) are kept at bay. It also adds compressive strength to concrete. For more information, click here.

Fly ash improves the workability of concrete and is commonly used when pumping concrete. It reduces bleed water during the finishing process. It is used to control set times in extremely hot weather. For more information, click here.

Slag cement improves both the compressive and flexural strength of concrete. It also improves the permeability of concrete and aids in the resistenceof cholrides and other corrosive chemicals. Slag makes concrete easy to pump and finish. It is the most common Pozzolan substitute for Portland Cement. For more information, click here.