A technical-environmental comparison of hybrid and blended slag cement-based recycled aggregate concrete tailored for optimal field performance

Abstract

The eco-design of concrete, employing a hybrid binder (HB) and recycled aggregates (RA), stands as a potential alternative for reducing CO2 emissions. This research assesses the impact of three RA percentages and HB/commercial CEM III/B binders on concrete formulations in terms of technical performance (compressive strength (CS), carbonation (DC), chloride migration (DCl), and transport properties. Results indicate that RA percentage is a more critical variable than the type of binder. Life-cycle assessment from cradle-to-gate reveals comparable CO2 emissions for all concrete formulations. Incorporating concrete design parameters such as CS, DC, and DCl in the functional unit shows carbon reductions between 10 and 60% for HB, with a diminishing benefit as the %RA increases. This underscores the potential of eco-designed concrete, particularly with HB, in achieving significant carbon footprint reductions. Careful consideration of RA percentages is essential for optimizing environmental benefits.