Roman ruins inspire scientists to create cement from volcanic rock, no kiln required

Scientists at Stanford, inspired by ancient Roman observations, have developed a new type of cement made from volcanic rock that requires no kiln and produces significantly less carbon dioxide. The research draws on Pliny the Elder’s account from 79 A.D., describing how volcanic ash from the Puteoli region (modern Pozzuoli) naturally hardens into stone when immersed in water—a property that contributed to the durability of Roman structures like the Pantheon. Traditional cement production involves heating limestone above 1,400°C, releasing about 8% of global CO₂ emissions, making it a major contributor to climate change. Tiziana Vanorio and her team studied volcanic rocks beneath the Campi Flegrei supervolcano near Pozzuoli, which had naturally undergone heating and lost carbonate content, thus avoiding CO₂ release during processing. They developed a method to crush these volcanic rocks into a cement-like material that forms tiny internal fibers, providing strength without the need for steel reinforcement. This innovative cement mimics natural