1 Early concrete history
2019-6-19 · Lime is burned from a reasonably pure limestone, from which the CO 2 is driven out and calcined at 1000–1100℃ but does not harden under water. Burnt lime treated with water and mixed with sand gives a lime mortar. The hardened mortar will continuously absorb CO 2 from the air and harden, something that in many ways is the reverse process of ...