When was cement invented?

1824, British construction worker Joseph Astin invented cement and obtained the patent right of portland cement. He used limestone and clay as raw materials, mixed them in a certain proportion, calcined the mature materials in a vertical kiln similar to lime burning, and then made cement by grinding. Because the color of hardened cement is similar to the stone used in construction in Portland, England, it is named Portland cement. It has outstanding architectural performance and epoch-making significance in the history of cement.

Extended data:

The earliest discovery process of cement:

1756, British engineer J. Smeaton found that in order to obtain hydraulic lime, limestone containing clay must be used for firing; The ideal composition of masonry mortar for underwater structures is made of hydraulic lime and volcanic ash. This important discovery laid a theoretical foundation for the research and development of modern cement.

The mixture of early lime and pozzolan is very similar to modern lime-pozzolan cement. After hardening, the concrete made of crushed stone not only has high strength, but also can resist the erosion of fresh water or salt water. For a long time, as an important cementing material, it has been widely used in civil engineering, water conservancy, national defense and other projects.

References:

Baidu encyclopedia-cement