Sustainability and its consequences on mix design, workability and casting of concrete

Abstract

Concrete is the largest volume material used by man and is irreplaceable for innumerable large infrastructure developments. From the point of view of natural resources, ecology and economy, it is virtually impossible to imagine substituting concrete by any other material. However, because of the large volumes used, its energy and CO2 footprint are important. This review paper examines some of the routes that may be followed to further reduce the environmental impact of concrete and focuses on the consequences from a fresh properties and casting processes point of view. The approach consists in extracting from life cycle assessment data the anticipated changes in mix design of concrete and derive from these the expected changes in terms of rheology and processing technologies along with the upcoming trends that shall allow for these change to become real. The questions of short-term perspective or long-term perspective alternative binders, new admixtures, crushed and recycled aggregates and emerging casting processes such as 3D printing are covered.