Eco-efficient design indices for reinforced concrete members

The production of cement, the primary binder in concrete, is resulting in notable environmental impacts worldwide. It has been argued that efficient use of cement in concrete and the efficient design of concrete components can be a means for reducing the impacts from these materials by lowering overall demand. In systems where concrete is the only material used, efficient design can often be related to requisite material properties; however, the concept of efficient use becomes more complex in multi-material systems, such as steel reinforced concrete. In this work, steps towards developing engineered methods for efficient design of reinforced concrete members are taken by developing equations to relate environmental impacts to the volume of concrete and volume of steel required. This work focuses on mitigation of greenhouse gas (GHG) emissions, but the equations developed can be extended to other environmental impacts as well. The results indicate that different member designs require different concrete mixtures and reinforcement cross-sectional areas to reduce GHG emissions; driving down cement content may not be the sole parameter for reducing GHG emissions from concrete.