Concrete is the world’s most versatile and most widely used construction material with total consumption presently estimated at 13.5 billion cubic yards. Depending on the required strength of the concrete, cement generally accounts for 10% – 15% of a concrete mix. This is relatively small when you consider it represents about 96% of the total carbon dioxide emissions associated with concrete production. For over 6 years Ohio Ready Mix, Inc. has experienced great success through the use of slag while helping to reduce the industries carbon footprint.
We have also been participating in a “Green Initiative” that replaces Portland cement with a supplementary cementitious material (SCM) known as Ground Granulated Blast Furnace Slag (GGBFS). Slag is obtained by quenching molten iron slag (a by-product of iron and steel making) from a blast furnace in water or steam, to produce a glassy, granular product that is then dried and ground into a fine powder. With both physical and set characteristics similar to Portland cement, replacement levels for GGBFS can range anywhere from 30% up to 85%. However, 40 to 50% replacement levels are most typically experienced. Since GGBFS is a by-product of the steel manufacturing process, its use in concrete is recognized by several Earth friendly organizations and certifications most notably: LEED and The Climate Trust i.e. Cool Climate Concrete.
The Cool Climate Concrete (C³) Program is a well monitored and verified greenhouse gas (GHG) offset program based upon the primary principle of replacing Portland cement with supplementary cementitious materials (SCMs) in concrete for construction and civil works projects. The strategy for reducing GHG emissions was developed because the majority of emissions related to concrete come from the production of its key ingredient, Portland cement. Due to the magnitude of the concrete industry, and the ability to effectively substitute SCMs in concrete, the Program can significantly reduce the associated CO2 emissions.
Ohio Ready Mix, Inc. is very excited to be a part of the Cool Climate Concrete Program and continues to focus on the “Green Initiative”.