Cement is one of the most useful materials in the construction industry. Cement itself is a soft powder, but when mixed with water it hardens, it can combine with sand or crushed stone to become a very solid solid object.
Cement is one of the important materials in the construction industry.
Currently, cement is made by heating limestone, clay or mineral ore slag at high temperatures. The above must be heated together until a glass-like sintered product is formed, and then crushed into a powder.
When water is mixed into cement powder, an extremely complex chemical reaction occurs, resulting in the formation of an artificial stone that is insoluble in water and has high abrasion resistance.
So how did a chemical reaction happen? How does cement become hard? This question chemists so far have not found an exact answer.
In cement there are mainly four compounds. It is thought that after adding water to those compounds, they will turn into crystals. Those crystals hook together, becoming a hard rock.
One thing that surprises us is that, as early as the 2nd and 3rd centuries BC, the ancient Romans knew how to make a hard cement in water. Their method is: mix volcanic ash with limestone powder. This is an outstanding contribution of the ancient Romans.