Challenges and Opportunities for Concrete in the Digital Era (2020-04)¶

Unloved by the majority and yet ubiquitous, concrete is the backbone of our modern built environment. More concrete is produced than any other synthetic material on earth. Twice as much concrete and mortar is used in construction—roughly 35 billion tons [1]—as the total of all other industrial building materials including wood [2], steel [3, 4], plastic [5], and aluminum [6]. Roads, bridges, tunnels, dams, power plants, ports, airports, dikes and seawalls, waste- and freshwater plants and networks—all these infrastructures rely on the extensive use of concrete, just like schools, hospitals, and public and commercial buildings. There seems to be no other currently known material available in the quantities required to meet the global demand for building and infrastructure. Although the word concrete is a generic term that applies to any granular composite to which cohesion is provided thanks to a binding phase—bitumen, clay, epoxy, lime, etc.—modern concrete relies almost exclusively on the use of Portland cement or its variants. Not surprisingly considering the success of concrete, the global demand for cement has seen an unprecedented growth in the last half-century, especially since the turn of the third millennium (Fig. 1). In relative terms, the increase of cement demand is surpassed by that of plastic [10] (Fig. 1), but in absolute terms, cement remains by far the largest industrially manufactured product. There is a wide consensus that this exceptional growth of cement and concrete consumption on the global scale is temporary and due to a handful of actors only among the emerging countries, China in particular [7, 8]. But there are also good reasons to consider that a slower but lasting growth will go on for long. Developed countries face the challenge of maintaining and upgrading their extensive but aging transport, power, water, and telecommunication networks, whereas many developing countries still dedicate a large fraction of their national income to satisfy basic human development needs like access to water, sanitation, electricity, and affordable housing. Altogether, this is likely to drive a lasting increase of concrete demand for decades to come.