There is now interest in ‘green cement”, which is made from waste such as incinerator fly ash and even old concrete.
IN Rome, the famous ancient building called the Pantheon is almost 2,000 years old. Yet the structure stands as it did two millennia ago. In fact, the dome is still recognised as the world’s largest unreinforced concrete dome. The structure is made from Roman concrete which often used not just lime and gypsum as binders, but also the much-preferred pozzolana, or volcanic sand.
