types of cement

merehan
Сообщения: 57
Зарегистрирован: 15 ноя 2022, 02:42

types of cement

Сообщение merehan »

types of cement
The name 'cement' is given to all adhesives of all kinds, but in particular it is called the materials that are used in building construction and civil engineering, which consist of finely ground powders mixed with water and then become solid and thus become a stabilizing material, and cement is a chemical mixture of cement compounds. With water, it produces sub-microscopic crystals or a gel-like substance with a high surface area and wetting properties, and it is called structural cement.

Cement is divided according to the hardening and setting mechanism into two main categories, hydraulic cement and non-hydraulic cement . Its types are also classified according to composition and properties. The most prominent types of cement are:

Ordinary Portland Cement
Ordinary Portland cement (OPC) is the type most commonly used in regular construction, and consists of Argillaceous or alumina silicate (clay, shale) and calcium carbonate or limestone (limestone, chalk, and marl).

Modified Cement
This type of cement has a lower heat of hydration than ordinary cement and a higher rate of heat development than 'low temperature cement' with a hardening rate similar to that of regular cement, and is usually used in structures with moderately low heat generation or in structures where A moderate sulfate attack occurs, and the country that uses the most modified cement is the United States.

Rapid Hardening Portland Cement
This type is characterized by that it hardens faster than ordinary Portland cement, meaning that its hardening strength in 3 days is equal to the strength of ordinary cement in 7 days, although the two types need the same preparation and setting time, and it has a higher rate of heat development than ordinary Portland cement because it contains C3S and C3A are more in addition to its high purity

and it is mainly used in construction that needs fast hardening, such as removing molds for reuse, or completing construction as quickly as possible, such as building sidewalks or heavy use places that cannot be closed for a long time, and it is preferable to use it when Building in areas with low temperatures to prevent frost damage

Low Heat Cement
This type of cement is characterized as being “spatial” and produces a low temperature of hydration during its preparation. This type of cement was produced by modifying the proportions of some chemical compounds in ordinary Portland cement to reduce the water temperature, and its basic chemical composition contains a low percentage (5% ) of tri-calcium aluminate (C3A) and a higher percentage (46%) of decomposed silicate (C2S), and it is used in the construction of large dam bases, large raft panels, wind turbine bases, and in the construction of chemical plants.

Portland Pozzolana Cement
Pozzolan (PPC) is a type of cement that consists of natural or synthetic materials containing silica in reactive forms. It reacts with calcium hydroxide from hydrated cement to form additional cementing materials when it is well divided. It consists mainly of OPC clinker, gypsum, and pozzolanic materials which are Fly ash, volcanic ash, calcined clay or silica fumes, and this type of cement is used in the construction of hydraulic structures, marine structures, buildings near the seashore, building dams, and in the manufacture of precast sewage pipes.

Quick Setting Cement
One of the most important characteristics of the type is that it is fast setting, as it takes 5 minutes for its initial preparation and 30 minutes for the final preparation, and it consists of clinker and aluminum sulfate with a ratio of 1% to 3% by weight of clinker, and it contains aluminum sulfate that increases the rate of hydration of silicate, and it is mainly used In underwater construction, in rainy and cold weather conditions, as well as for stabilization or rock mining and tunneling purposes

Sulphate Resisting Cement
This type of cement is used to resist sulfate attacks in concrete that occur due to the low percentage of Tricalcium aluminate by reducing the production of calcium sulfate, and is used in construction works in contact with soils containing more than 0.2% g/L of sulfate salts or Groundwater containing 0.3% g/L of these salts, and concrete surfaces subject to alternate exchange and drying, such as bridge piers or those built near the sea coast.

Blast Furnace Cement
This type is made by combining Portland cement residues and blast furnace residues with a maximum content of 65 percent. It is highly resistant to sulfate and is often used in construction in seawater.

High Alumina Cement
High alumina cement is obtained from a mixture of calcining bauxite, one of the aluminum ores, with ordinary lime and clinker during the manufacture of ordinary Portland cement, with a percentage of not less than 32% of alumina, and it is used in places where concrete structures are exposed to high temperatures such as workshops, refractories, foundries and places Where concrete is subjec

TRANSLATED FROM:
سعر متر الطوب الحرارى
انواع الحجر الهاشمى
حجر بازلت

Denis
Сообщения: 16
Зарегистрирован: 05 дек 2022, 10:23

Re: types of cement

Сообщение Denis »

Кто-то хочет помочь нам цементом, но не всё понятно. Можно ли на форуме подключить электронного переводчика?

Ответить