What is a Cement Block?

Powdery hydraulic inorganic gelling material. After adding water and stirring, it will become a slurry, which can be hardened in air or better in water, and can firmly cement sand, stone and other materials together. The mixture of lime and pozzolan in early days is very similar to modern lime pozzolan cement. The concrete made with it is hardened not only with high strength but also resistant to erosion by fresh water or salt water. For a long time, as an important gelling material, it is widely used in civil engineering, water conservancy, national defense and other projects.

Cement is divided into:

(1)

The production process of Portland cement is representative in cement production. It takes limestone and clay as the main raw materials, crushes, mixes and grinds it into raw meal, then feeds it into the cement kiln to calcine the mature material, and then matures it. Add an appropriate amount of gypsum (sometimes mixed with

In 1756, the British engineer J. Smitton studied the characteristics of the hardening of certain limes in water and found that: to obtain hydraulic lime, limestone containing clay must be used for firing; The ideal composition is made up of hydraulic lime and pozzolan. This important discovery laid a theoretical foundation for the research and development of modern cement.

In 1796, the British J. Parker fired a cement from marl, which had a brown appearance, much like a mixture of lime and pozzolan in ancient Roman times, named Roman cement. Because it is made of natural marl as raw material and is directly fired without ingredients, it is also known as natural cement. With good hydraulic and fast setting characteristics, it is especially suitable for projects in contact with water.

In 1813, French civil engineer Piga discovered that a three-to-one mixture of lime and clay had the best performance.

In 1824, the British construction worker Joseph Aspdin invented the cement and obtained the patent right of Portland Cement. He uses limestone and clay as raw materials, mixes them in a certain proportion, then calcines the mature materials in a vertical kiln similar to that of burning lime, and then grinds them into cement. The cement was named Portland Cement because it hardened in color and was similar to the stone used for construction in Portland on the island of England. It has excellent building properties and has epoch-making significance in the history of cement.

In 1871, construction of a cement plant began in Japan.

In 1877, Crampton of England invented the rotary furnace, and in 1885 it was reformed into a better rotary furnace by Lansham.

In 1889, near the Kaiping Coal Mine in Tangshan, Hebei, China, a Tangshan "fine cotton" plant produced by a vertical kiln was established. In 1906, Qixin Ocean Ash was established on the basis of the plant, with an annual output of 40,000 tons of cement.

In 1893, Hideto Endo and Sanzhen Utsumi invented Portland cement that was not afraid of seawater.

In 1907, France's Bière used iron bauxite instead of clay and mixed limestone to make cement. Because this cement contains a large amount of alumina, it is called "alumina cement".

In the 20th century, while continuously improving the properties of Portland cement, a number of cements suitable for special construction projects were successfully developed, such as high alumina cement, special cement, etc. The world's cement varieties have grown to more than 100, and the annual cement output in 2007 was about 2 billion tons. China formulated the first unified national standard in 1952, determined that cement production is based on the principle of multi-variety and multi-label, and renamed Portland cement as Portland cement based on the main mineral composition it contained, and later as silicon. Portland cement so far.

In 2012, China's cement output reached 2.184 billion tons, accounting for more than 50% of the world's total. ^{[2] [2]}