reportCement based materials
Cement is a binder which sets and hardens within a certain time and which is able to bind fine and coarse aggregates. Depending on the aggregates different materials are produced such as concrete, mortar, stucco and grout. Concrete consists of cement, different cementitious materials, coarse and fine aggregates, chemical additives and water.
Portland cement is the most frequently used type of cement. It mainly consists of limestone, clay and gypsum that get hydrated due to a chemical reaction with water making the material hard and extremely durable. Thus the material will harden in the presence of water. For this reason cement is also referred to as hydraulic binder. In general, binders are divided into hydraulic and non-hydraulic types, whereby Portland cement is the most common hydraulic binder. Portland cement clinker is produced in huge rotating kilns at maximum temperatures of about 1450 degrees Celsius due to the sintering of limestone and clay. This process produces a solid material named clinker. After grinding the clinker in a mill and adding materials such as calcium sulfate, blast furnace slag, fly ash or silica fume the material is sold as cement. These additional material are commonly referred to as admixtures. The name of the cement may vary (e.g. Portland blast furnace slag) depending on its composition according to the CEM nomenclature (EN 197-1, www.cenorm.be). Portland cement is also known as ordinary Portland cement (OPC).
Visits: 110, Published on: November, 11th 2008, 11:09 AM, Size: 1 KByte