abundance of building materials tough limestone and pots of money cash. if. and the roman already know how to use them to produce very light concrete in order to me the buildings such as the pantheon in rome that uses these the can if you put in order you will float because it s volcanic glass full of pores and you see here you have more sandy it s use it for the mixing with lime to obtain the concrete and this is the real good one he has a lot of properties and the most important one is that it s almost the last saw ready to react with other constituents to build the new phrases that are responsible within the concrete of their strength less of their resistance