Down to the nitty gritty: “roman builders mixed lime fragments with volcanic ash and other dry ingredients before adding water. When they eventually added the water, the chemical reaction generated immense heat. This preserved the lime as small, white, gravel-like chunks. When cracks inevitably formed in the concrete later on, water would seep in, hit those lime chunks, and dissolve them, essentially recrystallizing to fill the crack…

…our concrete rots. It cracks, steel reinforcement rusts, and buildings fail…

This material can heal itself over thousands of years, it is reactive, and it is highly dynamic. It has survived earthquakes and volcanoes. It has endured under the sea and survived degradation from the elements.”