Lessons from Roman Cement and Concrete

Although masonry and lime mortars had been used for centuries by earlier civilizations, the Romans were the first to extensively use naturally occurring volcanic earth to make hydraulic cement. The volcanic powder named “pulvis puteolanis,” found near the town of Puteoli near Naples (now Pozzouli), was used to build magnificent structures. The use of this hydraulic cement in masonry and concrete greatly expanded civil engineering possibilities. The Roman engineer Vitruvius, writing in The Ten Books on Architecture, described the careful materials selection, proportioning, and workmanship that was critical to the performance of Roman concrete. Masonry and coarse and fine aggregates were carefully selected for durability. Hydraulic cement concrete was used extensively for constructing bridge piers and harbor jetties. One of the greatest examples of Roman concrete construction was the dome of the Pantheon, with its 43.4-m span. The vast system of aqueducts also made extensive use of hydraulic cement. This paper summarizes the materials and construction methods used in Roman concrete construction, as well as structures and infrastructure built with concrete.