THE ANCIENT Romans were the first to mix sand and gravel with water and a bonding agent to make con­crete. Although they called it opus cementitium, the bonding agent differed from that used in modern cement: It was a mixture of gypsum, quicklime, and pozzolana, a volcanic sand from Puteoli, near Mount Vesuvius, that made an outstanding material fit for massive vaults. Rome's Pantheon, completed in 126 C.E., still spans a greater distance than any other structure made of non-reinforced concrete.

中文翻译：

---

具体事实-[CrossTalk]

古代罗马人是第一个将沙子和碎石与水和粘结剂混合以制成混凝土的人。尽管他们称其为水泥胶合剂，但该粘合剂与现代水泥中所用的粘合剂不同：它是石膏，生石灰和火山灰（一种来自维苏威火山附近普特奥利火山岩的火山砂）的混合物，这使得它非常适合大型拱顶。罗马的万神殿于公元126年完工，但其跨度仍比其他非钢筋混凝土结构大。