- July 4, 2022
- Posted by: admin
- Category: physical commodities
Cement is the core of every construction. Everything is made of cement, whether a road, bridge, dam, house, building, pavement, or office. But did you know there are many different types of cement, and each has its specific use based on its properties? If not, this article sure is going to make for an enlightening read.
Cement is an almost white powdery substance that is made by calcining lime and clay. When mixed with water, it forms mortar; when combined with sand, gravel, and water, it forms concrete.
Ingredients Of Cement
Cement is a binding material whose presence you will find in almost all kinds of construction. The elements or the raw materials that make cement give it unique properties. Hence, the ingredients of cement are of great interest to civil engineers.
Since we are talking about cement, it is good to know the major ingredients that come together to form it.
- Lime – 60% to 65%
- Silica – 17% to 25%
- Alumina – 3% to 8%
- Magnesia – 1% to 3%
- Sulfur Trioxide – 1% to 3%
- Alkaline – 0% to 1%
- Iron Oxide – 0.5% to 6%
- Calcium Sulfate – 0.1% to 0.5%
Types Of Cement
Usually, cement has thirteen different types. These are:
- OPC or the Ordinary Portland Cement.
- PPC or the Portland Pozzolana Cement.
- Quick Setting Cement
- Rapid Hardening Cement.
- White Cement.
- Low Heat Cement
- Blast Furnace Slag Cement.
- Sulfate Resistant Cement.
- Air Entraining Cement.
- High Alumina Cement.
- Expansive Cement.
- Hydrographic Cement.
- Colored Cement.
5 Main Types Of Cement And Their Uses In Concrete Construction
Although many types of cement are available for one to use, today we shall concentrate on its 5 main varieties and their uses in concrete construction.
1. Ordinary Portland Cement – OPC happens to be the most widely used type of cement. It is suitable for almost all kinds of general construction where special properties are not required. The demand for OPC is extremely high worldwide. Therefore, to meet the high demand, its production happens on a vast scale. Just to give you an idea, the global production of Ordinary Portland Cement is approximately 3.8 million cubic meters annually.
OPC is used where cement or concrete does not have to face certain exposures, like sulfate attack from water or soil or intolerable temperature rise because of the heat generated by hydration. Its uses include making sidewalks and pavements, railway structures, reservoirs, tanks, masonry units, water pipes, etc.
2. Portland Pozzolana Cement – PPC is obtained by grinding together pozzolanic clinker and Portland cement. Another method of making Portland Pozzolana Cement is to combine the pozzolana with calcium sulfate or gypsum. The blending or combining has to be uniform and extremely fine.
PPC is a unique cement with remarkable properties. As compared to OPC, it has high resistance to chemical attacks. Therefore, it is widely used in sewage works, marine structures, hydraulic structures, and laying concrete underwater, as is the case in the construction of dams, bridges, piers, etc. It is also suitable for some common applications like plastering and masonry mortars.
3. Quick Setting Cement – As is clear from the name itself, Quick Setting Cement is the one that sets quickly. It sets quickly and gains strength slowly. The rate at which it gains strength is the same as that of Ordinary Portland Cement. Typically, this type of cement is used where the work needs to be completed in a short period of time.
4. Rapid Hardening Cement – Some people tend to get confused between Quick Setting Cement And Rapid Hardening Cement. So let’s clear the doubt. Quick Setting Cement is that which sets quickly and gains strength slowly. On the other hand, Rapid Hardening Cement gains strength very fast.
Rapid Hardening Cement has a high content of lime and tricalcium silicate. It also has a finer grind. This helps it gain strength far more quickly than OPC. Just to give you an idea, the strength gain of rapid hardening cement at 3 days is the same as the strength of OPC at 7 days with the same water-cement ratio. By saving formwork costs, Rapid Hardening Cement makes for a faster construction rate and lower construction costs.
Rapid Hardening Cement is used in industries where prefabricated concrete products are made, such as electric poles, slabs, block fences, posts, etc. It is considered a suitable option for cold weather constructions because the rapid evolution of heat during hydration does not allow the concrete to freeze.
5. White Cement – White Cement is rightfully a sub-type of Portland Cement but costlier than both OPC and PPC. It is made from raw materials that are free of iron oxides, which is how it gets its white appearance. Do not confuse it with Plaster of Paris, as PoP is made of gypsum and used for making medical casts, while White Cement is used to give a lustrous finish to walls.
This cement generally finds application for decorative architectural purposes. Some examples are precast curtain wall that faces the panels, interior and exterior decorative work in buildings, garden paths, floorings, repairing marble tiles, etc.
Cement is a very sought-after product used as a binding material in all constructions. It forms a bond between the aggregates and reinforcing materials to make the structure strong and give it an even and smooth finish. Thanks to the massive developments in technology, today, several types and qualities of cement are available, each of which meets a specific purpose. The most common and widely used is the Ordinary Portland Cement. If you want rapid strengthening, you can opt for Rapid Hardening Cement, and if the fast setting is your main requirement, there’s always the option of Quick Setting Cement. So depending on what specific qualities one is looking for, there’s always a cement to meet your needs and expectation.