TLDR: Cement is a substance used in construction to bind materials together. It is commonly used to make concrete, which is the most widely used building material in the world. There are different types of cement, including hydraulic cement (which sets and hardens through a chemical reaction with water) and non-hydraulic cement (which sets as it dries and reacts with carbon dioxide in the air). Cement production is a major contributor to carbon dioxide emissions and climate change.

Cement is a binder that is used in construction to hold materials together. It is typically used to bind sand and gravel together to make concrete. Concrete is a versatile and widely used material that is used in buildings, roads, bridges, and many other structures. It is made by mixing cement with fine aggregate (such as sand) and coarse aggregate (such as gravel) and then adding water to create a paste that hardens over time.

There are different types of cement used in construction. Hydraulic cements, such as Portland cement, set and become adhesive through a chemical reaction between the dry ingredients and water. This chemical reaction produces mineral hydrates that are durable and can set in wet conditions or under water. Non-hydraulic cement, on the other hand, does not set in wet conditions or under water. Instead, it sets as it dries and reacts with carbon dioxide in the air. Non-hydraulic cement is resistant to chemical attack after setting.

The production of cement has a long history, dating back to ancient times. The word "cement" can be traced back to the Ancient Roman term "opus caementicium," which described masonry made from crushed rock with burnt lime as a binder. The Romans discovered that volcanic ash (pozzolana) mixed with lime produced a hydraulic binder that could set underwater. In modern times, organic polymers are sometimes used as cements in concrete.

Cement production is a major industry worldwide, with about four billion tonnes produced each year. China is the largest producer of cement, accounting for about half of the world's production. However, the production of cement is also a major contributor to carbon dioxide emissions and climate change. The calcination reaction in the production of cement is responsible for about 4% of global CO2 emissions, and the overall process is responsible for about 8% of global CO2 emissions. Efforts are being made to reduce the environmental impact of cement production, such as using alternative fuels and developing more sustainable cement blends.

In summary, cement is a binder used in construction to hold materials together. It is commonly used to make concrete, which is the most widely used building material in the world. There are different types of cement, including hydraulic cement and non-hydraulic cement. Cement production is a major contributor to carbon dioxide emissions and climate change, but efforts are being made to reduce its environmental impact.

Related Links:

• Concrete