Green concrete: optimization of high-strength concrete based on LCA

The construction industry is accountable for about 50 percent of the global resource consumption. Within this, traditional concrete is one of the products with a manufacturing process that has a relatively large impact on the environment. As a result of the rising awareness regarding sustainability, concrete suppliers, product manufacturers, and building contractors are concerned about which environmental impact their product has. Based on a life cycle assessment (LCA) it is possible to analyze the different stages in the life cycle of structures and to evaluate the respective impacts. Such a study is presented here for a producer of high-strength concrete building materials, applying a cradle-to-gate approach with options. Specific company data were combined with general input from databases, and a functional unit of 1m³ was adopted to be able to compare the different results. Based on this, it was determined that whereas the reinforcing and prestressing steel and the cement dominate the impact contributions, other factors such as transport by road, maintenance, aggregates, fabrication and concrete waste production during fabrication are non-negligible. A further impact study shows that several adaptions can potentially reduce the impact on the environment with 20 to 30 percent, depending on the assessment method used.