Manuel F. Herrador
Doctor of Civil Engineering, Professor of Concrete Structures, researcher at the Construction Group (gCONS) of CITEEC (Centre for Technological Innovation in Building and Civil Engineering) at the University of A Coruña.
This article is interesting and of good quality, and you can learn from it if you are familiar with the subject, but for people outside the field of concrete, it may raise somewhat exaggerated expectations. To begin with, the formulation of Roman concrete is well known because it has been recorded in writing. We do indeed know that it is a more durable concrete than those commonly used today, but also that it is less resistant, takes longer to set, depends on components (such as volcanic ash) that are not easily obtainable everywhere, and in some of its most striking uses (I am referring to mixtures with seawater) is incompatible with the steel reinforcement that is essential in our reinforced and prestressed concrete structures.
We have already learned the lessons of Roman concrete, so much so that similar concretes can be manufactured in accordance with regulations that allow the use of ash additives; in fact, they are commonly used in structures with special durability requirements, and their drawbacks are taken into account in the design.
All studies that contribute to the decarbonisation of cement (a very real problem and well addressed in the article) are welcome, but today there are much more promising lines of research into so-called “green cements”, using other industrial by-products such as blast furnace bottom ash or waste from the timber industry.