The word cement means adhesive. Therefore, bone glue and marrow glue can also be said to be substances like cement. But the cement we are talking about today only refers to portland cement. Portland cement was invented in19th century, but as early as 1700 years ago in ancient times, when building brick houses, the Romans enthusiastically studied how to make bricks stick to each other.
The Romans first used lime as a binder for making bricks. Ordinary lime is called quicklime. When water is added, it becomes sticky hydrated lime, and when sand is mixed, it becomes mortar. Mortar absorbs carbon dioxide in the air and becomes calcium carbonate, which gradually solidifies. Therefore, mortar can be used as a binder for bricks.
However, the Romans further baked lime, gypsum and volcanic ash and invented better adhesives. This is very similar in nature to the cement used today, and the Romans also used this adhesive as reinforcement cement. In Roman architecture, stones and bricks are often used to build walls in two layers, and this kind of "cement" is added in the middle to solidify them.
Because the Romans invented this excellent "cement", Europe has been using this Romanesque "cement" since then.
But in the18th century, because of the invention of the steam engine and the textile machine, the industrial revolution took place. In order to transport a large number of products, high-quality cement is very needed, and Roman-style "cement" is not enough. It is precisely because "necessity is the mother of invention" that new inventions can continue to emerge.
1756, a lighthouse in Plymouth Harbor, England caught fire, and the government ordered technician Smithton to rebuild the new lighthouse. Smithton first focused on limestone roasting cement. However, it was sent with black and inferior limestone. At that time, people thought that only white lime could produce excellent cement, so Smithton had to change his mind and use this black limestone to burn cement. But at first glance, the cement produced is far better than the cement fired by pure white limestone. Smithton was surprised to analyze the reasons. It turns out that this black limestone contains clay.
"Probably because of clay, cement has become better!"
So he added clay to limestone with less clay for roasting experiment, and finally found out that limestone with clay content of 6~20% was the best raw material for roasting cement.
In this way, Smithton built a spectacular lighthouse with this cement made of black limestone.
The news of Smithton's success soon spread all over Europe. French civil engineers, like Britain, are in urgent need of strong cement, and they immediately carried out experiments according to Smithsonian's research. But we can't get the black lime center containing clay, so we must add clay to limestone.
French civil engineer Gaby is also keen to study it.
18 13 years, he finally found that the cement made by mixing lime and clay in a ratio of three to one has the best performance.
1824, on the basis of Gaby's research, Joseph asp of England burned a mixture of 30% limestone and 10% clay into powder in a furnace to make cement. He named this cement "Portland cement". William Aspding, the son of Aspding, inherited his father's ambition and continued to study the manufacturing method of cement.
It is generally believed that Portland cement was invented by Applestein and his son. In fact, they are made by Gaby's research results.
At this time, France invented a new kind of cement.
1907, Pierre used bauxite from aluminum mine instead of clay and mixed limestone to make cement. This kind of cement is called "bauxite cement" because it contains a lot of alumina.
Portland cement is afraid of seawater and should not be used to build lighthouses, ports and docks, but this bauxite cement has the characteristic of being afraid of seawater.
In this way, focusing on the research competition between Britain and France, Europe produced a large number of high-quality cement and soon introduced it to the United States and Japan.
The earliest cement plant in Japan was built in 187 1 year, 30 years earlier than the invention of bauxite cement in France.
At that time, in Britain, the roasting furnace for burning cement was not perfect enough. Six years after the Japanese cement plant was built, crampton of Britain invented rotary furnace in 1877, and Langsam transformed it into a better rotary furnace in 1885.
The widespread use of cement in Japan began with 1887. 1893, Endo Hideyoshi and Sanzhen Inland Sea invented portland cement which is not afraid of seawater, and obtained the patent right. Beable invented bauxite cement even earlier.
Later, with the development of roads, bridges and modern buildings, the demand for cement is increasing, and Japan's cement industry is booming, surpassing Europe and America.
Since Japan had produced cement before Pierre invented bauxite cement in France, portland cement is still the main product in Japan until today.
In recent years, white clay has been used instead of black clay to produce white cement.