Comparative cradle-to-gate LCA of Concrete mixes Containing By-Products, Nanomaterials and Recycled Aggregates

Structural engineers have an important role in the development of sustainability concept. The main reason is due to the necessity to reduce the energy and resource requirements and the environmental impacts from the construction process. In a specific way, the task for a structural engineer is not only the application of structural concepts, but also and above all sustainability promotion and education. While research is essential for a forthcoming future, education is focused in impressing sustainability concepts in the future generation of younger engineers. Traditional construction materials consume large amounts of raw materials and energy, and contribute to environmental impact. In the last few years, numerous alternative materials, from by-products to agricultural waste materials and recently developed nano-materials, have been used as cement and aggregate replacement. Due to the population and economic growth, building sector has gained quite significant weight in matter of energy consumption and carbon footprint emission, fuel and raw materials depletion, and waste production which need to be measured. In the last few years, considerable works have made into developing systems to measure an environmental performance of a building over its life. Generally, frameworks can be divided in two groups: qualitative tools, based on scores and criteria, and quantitative tools using a physical life cycle approach. Quantitative frameworks are the most used in helping engineers in decision making regarding sustainability constructions with quantitative input and output data on flows of matter and energy. These tools are important to structural engineering application as they are to structural engineering education. This study is focused on the environmental assessment of concrete made with Supplementary Cementitious Materials (SCMs): y ash, slag and silica fume; and Engineered Nano-Materials (ENMs): nano-silica, nano calcium carbonate and ultrafine fly ash as partial cement replacement, and construction and demolition (C&D) waste as virgin aggregate substitution. The potential beneficial role (compressive strength and durability) and sustainability value of these new concrete formulation is assessed and reported. Concrete is a major contributor to GHG production in the world. Revised formulations could go a long way in improving the sustainability performance of the structural engineers dark friend concrete.