What is Special Cement?
Special cement is a kind of special cement, which can be said to be a more characteristic cement. The feature mentioned here is because it has some special uses or is used in some specialized projects. Because of its many characteristics and its convenient use, special cement is very popular.
Classification of special cement:
Fast hard cement. Also known as early strength cement, the label is usually determined by the value of the 1 or 3 day compressive strength of the cement.
Low heat and medium heat cement. This type of cement has a low hydration heat and is suitable for dams and other large-volume buildings.
Sulfate resistant cement. Cement with high resistance to sulfate corrosion.
Oil well cement. Cement used exclusively for oil wells and gas well cementing projects, also known as plugging cement. According to the use, it can be divided into ordinary oil well cement and special oil well cement. Ordinary oil well cement is made of Portland cement clinker composed of appropriate minerals and appropriate amount of gypsum. If necessary, it can be blended with active mixed materials (such as slag) not exceeding 15% of the weight of cement, or 10% of the weight of cement. Inactive mixed materials (such as quartz sand, limestone). China's common oil well cement is divided into four varieties of 45°C, 75°C, 95°C and 120°C according to the depth of oil (gas) wells. It is suitable for cementing projects of general oil (gas) wells.
Expanded cement. The cement with volume expansion during hardening is divided into silicate expansion cement, aluminate expansion cement, sulphoaluminate expansion cement and calcium hydroxide expansion cement according to different mineral composition. Silicate expansion cement, alumite expansion cement, iron oxide expansion cement, magnesium oxide expansion cement, K-type expansion cement, etc. belong to silicate expansion cement. Such cements are typically milled in Portland cement with various expansion components.
Uses of special cement:
Special cements have special properties and special purposes. Commonly used varieties are white portland cement, colored cement, fast hard portland cement, fast setting fast hard portland cement, low heat cement, medium heat cement, oil well cement, sulfate resistant portland cement, masonry cement, refractory cement, expanded cement and radiation-proof cement.