The construction industry is constantly growing and demanding more materials to support its progress. Portland cement production is highly energy consuming and greenhouse gases emitting, and there are great efforts to minimize the environmental impact of the cement manufacturing. International agreements for reductions on the greenhouse gas emission exert pressure in the industry by demanding the reduction of CO2 emissions by 80% prior to 2050, while the production is expected to double as the world’s population is forecasted to reach 9 billion people by 2050; with this comes a substantial need for infrastructure and urbanization and an enormous demand for cement. Cement manufacturing produces approximately 2.4% of the global CO2 emissions from industrial and energy sources. This means that this process and material characteristics have to change significantly in the near future if these reductions are to be achieved. There are efforts from the cement and concrete industry on finding alternatives not only to reduce the emission of CO2, but also to develop materials that can capture the CO2 from the environment during its production and service life, becoming carbon-zero or even carbon-negative. Technologies being developed range from traditional clinker materials, to alternative cements and binders, and are reviewed in this paper. This article was previously published at the Second International Conference on Concrete Sustainability (ICCS) in Madrid, Spain, in 2016.
