Cement, A Sustainable Material?

Posted on May 9, 2008
Tag(s): Green Furnishings, Going Green | | Email this

Cement is found in many building products, from fiber cement siding to concrete flooring and countertops, as well as cement backer boards and insulated concrete forms (ICFs). It is increasingly appearing in conjunction with green building strategies. But as with most green products, it is not 100% sustainable. Let’s take a look at its positive attributes to see how they compare to the negative characteristics.

Cement is comprised mainly of limestone (an abundant mineral, that’s a positive), as well as sand and clay, and is the main ingredient in concrete. Most cement plants rely on nearby limestone quarries (another positive). Take a virtual tour of the cement-making process here. Although the making of cement is an energy-intensive one (a big negative), efforts are undertaken to save energy through heat recovery during the process. Plus, the longevity of cement products helps to outweigh the embodied energy used in its production (positive). The reuse and minimizing of waste of raw materials during the manufacturing process is also a positive step.

Even though the greenhouse gas carbon dioxide (CO₂) is the principal emission from the cement industry, much progress is continually being made to reduce emissions. Environmental Construction + Design Magazine states, “Cement plants across the U.S. and Canada are participating in industry-generated programs designed to improve energy efficiency and reduce emissions. In the United States, the cement industry’s aggressive efforts to reduce emissions and increase the use of supplementary cementitious materials in concrete (SCMs—primarily fly ash and slag cement) have had a positive impact.”

According to the Portland Cement Association, “Today, the cement industry fuel CO₂ accounts for less than 3% of U.S. industrial CO₂ emissions, well below other sources such as the petroleum industry (21.8%), chemical industry (22.2%), and iron and steel mills (9%).”

Some limestone quarries have successful rehabilitation programs in place that restore biodiversity to former quarry sites.

Another positive effort is the Cement Sustainability Initiative of the World Business Council for Sustainable Development which is a global alliance of 18 major cement producers who recognize that sustainable development is good business.

Learn more about progress being made in the cement industry here and review case studies here.