There are numerous variations within the five categories of cement recognized by the American Society for Testing and Materials (ASTM) to allow the creation of concrete that can withstand additional stress, water, chemical corrosion, and more. This article will define cement and discuss the components and uses of the various types of cement used in construction and civil engineering, ranging from hydrophobic cement to more common cement like OPC. At a glance:
Clay and limestone are combined to make standard cement. The two ingredients are combined, heated in a kiln, and the resulting clinker is ground into a fine powder to create it. Despite being frequently confused with concrete, cement is a component of concrete. Cement, water, and sand and stone aggregates are combined to create concrete. In our article on concrete vs. steel, we go into more detail about the differences between these two materials. cement.
By varying the proportions of ingredients and adding different ingredients, different types of cement can be created. Due to these improvements and modifications, cement can now be used for sulfate-resistant applications like sewage systems in addition to general construction projects. The full list of the five fundamental types of cement recognized by ASTM, in addition to Portland cement, is as follows:
Types of Cement
Cement and concrete
When a paste of water and cement is combined with an aggregate, such as sand and rock, concrete is created. to harden. Through a process known as hydration, the paste hardens and bonds with the aggregates. By volume, cement makes up 10% to 15% of a concrete mix
What is cement?
A fine gray powder known as cement is produced by combining chemicals and raw materials. It is a manufactured ingredient used in concrete. Raw materials in cement may include:
These components are mixed with minerals and metals like calcium, silicon, iron, and aluminum before being heated to high temperatures to create a solid substance known as clinker. After that, clinker is ground into a powder and sold to ready-mix concrete companies as cement.
Regular chemical and physical tests are used to monitor each stage of the manufacturing process to make sure the cement meets industry standards. Despite the fact that testing procedures may be the same everywhere, references to particular cement standards may vary by region Scientists can check the content and composition of cement samples using oxide analysis. Some physical features they may inspect may include:
Cement types
Depending on the conditions and the purpose of your project, you can use a variety of cement types. They include:
1. Ordinary Portland cement (OPC)
The most popular type of cement produced and used globally is regular Portland cement. A type of building stone quarried on the Isle of Portland in Dorset, England, gave rise to the generic name “Portland.” The majority of general concrete, mortar, or stucco construction projects can be completed using OPC.
2. Portland pozzolana cement (PPC)
Portland pozzolana cement is produced by manufacturers by grinding pozzolanic clinker, occasionally with the addition of gypsum or calcium sulfate. It is more resistant to various chemical reactions occurring in concrete than OPC. Projects like bridges, piers, dams, marine structures, sewage works, or underwater concrete projects frequently use PPC.
3. Rapid-hardening cement
Because of its high strength in the early stages of the hardening process, contractors or construction teams may opt to use rapid-hardening cement. With the same water-to-cement ratio, its strength after three days is comparable to OPC strength after seven days. Better strength development, increased lime content, and finer grinding could all be characteristics of rapid-hardening cement. It is frequently employed for projects involving the removal of early-stage formwork or when the goal is to accelerate construction and cut costs.
4. Extra-rapid-hardening cement
More quickly than OPC and rapid-hardening cement, extra-rapid-hardening cement can set and harden. This is achieved by adding calcium chloride to rapid-hardening cement. Due to its rapid setting rate, this cement type might be useful for concrete projects in cold climates.
5. Quick-setting cement
This concrete type may harden and become stronger even more quickly than OPC and rapid-hardening cement, similar to extra-rapid-hardening cement. While similar to OPC in terms of grain and strength rate, it hardens more quickly. For projects that must be completed quickly or that are situated close to standing or flowing water, quick-setting cement may be useful.
6. Low-heat cement
Manufacturers produce low-heat cement by monitoring the percentage of tricalcium aluminate in the mixture to ensure it stays below 6% of the whole This makes this type of cement less reactive and more resistant to sulfates than other types of cement by enabling low heat to be maintained during the hydration process. It might be appropriate for mass concrete construction or initiatives to prevent heat-related cracking in concrete. Low-heat cement, however, might take longer to set up initially than other types.
7. Sulfate-resisting cement
Concrete sulfate side effects are less likely with the use of sulfate-resistant cement. It is most frequently used to build foundations in soil that contains a lot of sulfates. Additionally useful for retaining walls, culverts, and canal linings are projects involving this type of concrete.
8. Blast furnace slag cement
Manufacturers make blast furnace slag cement by grinding clinker with up to 60% slag As a result, cement is produced that shares many OPC’s characteristics. It might, however, be less expensive to produce than other types, making it a wise choice for projects with a tight budget.
9. High-alumina cement
Bauxite and lime are melted together to make high-alumina cement, a type of rapid-hardening cement, which is then ground with clinker. It may be more flexible and workable than OPC, has a high compressive strength, and In applications where cement is exposed to harsh weather conditions, such as high temperatures or frost, high-alumina cement may be used.
10. White cement
White cement is a variety of OPC that is white rather than gray in color. It is made from raw materials without iron oxide and could be more expensive than other types of cement. It is used for architectural projects, as well as interior and exterior decoration initiatives like garden paths, floors, swimming pools, and decorative concrete goods.
11. Colored cement
Colored cement has properties similar to OPC and white cement. Manufacturers mix 5% to 10% mineral pigments with OPC to achieve the desired color Similar to white cement, this kind is frequently used by contractors for projects and decorative purposes.
12. Air-entraining cement
Compared to OPC and other types of cement, air-entraining cement can be worked with less water. To create this cement, producers add air-entraining substances like glues, sodium salts, and resins to the clinker during the grinding process. It may be used for frost resistance in concrete.
13. Expansive cement
Expansive cement can gradually enlarge without contracting as it hardens. It might be useful for tasks like grouting concrete ducts or anchor bolts.
14. Hydrographic cement
Manufacturers create hydrographic cement by mixing in water-repelling chemicals. This type of cement is highly workable, strong, and water-repellent to prevent weather damage. Projects like dams, water tanks, spillways, and water retaining structures may use hydrographic cement.
15. Portland-limestone cement (PLC)
Portland-limestone cement is a blend of Portland cement and 5% to 15% fine limestone Its properties are similar to Portland cement for general use but has about 10% lower greenhouse gas emissions
Cement creation methods
There are two common methods for creating cement:
Dry method
The dry method is the most common method. Steps include:
Wet method
The dry method and the wet method both use a similar process to create cement. However, the wet method involves grinding the raw materials with water before feeding them into the cement kilns.
Cement compounds
Four primary compounds, also referred to as phases, are created by high temperatures in the cement kiln to make Portland cement. They include:
C3S (tricalcium silicate)
Tricalcium silicate can make up 50% to 70% percent of an OPC clinker It promotes rapid hydration and hardening. As in rapid-hardening cement, increasing the amount of tricalcium silicate in the mixture may improve the mixture’s hardening and strength properties.
C2S (dicalcium silicate)
Dicalcium silicate comprises 10% to 25% of an OPC clinker. It hardens and hydrates slower than tricalcium silicate.
C3A (tricalcium aluminate)
OPC clinker may have up to 10% tricalcium aluminate in its composition This phase, which is the most reactive of the four main compounds, aids in the development of early age strength. During the first few days of hydration, it can produce heat. Less tricalcium aluminate in cement may make it more resistant to sulfates in water and soil.
C4AF1 (tetracalcium aluminoferrite)
OPC clinker may have up to 15% tetracalcium aluminoferrite in its composition This compound contributes to the traditional gray color of cement.
Cement specifications
Construction professionals can choose which type of cement to use and understand how it works in concrete by using the specification code, which is made up of letters and numbers.
Specifications for Portland cement
All Portland cement is the same, but different varieties are produced to meet various physical and chemical specifications for particular applications. Specification codes include:
Specifications for blended cement
Portland cement is mixed with other materials like limestone, slag cement, or pozzolans like fly ash, silica fume, or calcined clay to create blended cements. Specification codes include:
Additionally, blended cements can be categorized according to unique characteristics like heat development and sulfate resistance. To describe the type and use, suffixes are added to the specification code, such as Type II(MH).
Specification code suffixes
FAQ
What are 3 types of cement?
- Ordinary Portland Cement (OPC) …
- Portland Pozzolana Cement (PPC) …
- Rapid Hardening Cement. …
- Extra Rapid Hardening Cement. …
- Low Heat Cement. …
- Sulfates Resisting Cement. …
- Quick Setting Cement. …
- Blast Furnace Slag Cement.
What are the 6 types of cement?
- Ordinary Portland cement (OPC), which is a material for general use, is type 1.
- Type 2 has a mediocre sulfate resistance, and its MH variant has a mediocre heat of hydration resistance.
- Type 3 cement is an extra rapid hardening cement. …
- A low heat cement known as Type 4 emits less heat as it sets and dries.
What is Type 2 cement used for?
- Type I; Ordinary Portland Cement (OPC). This is a general purpose cement with no special properties.
- Type IP; Blended Cement (Pozzolan). This is a general-purpose cement that is primarily employed for plastering and concreting.
- Type II Cement. …
- Type III Cement. …
- Type V (SR Cement. …
- Class “G” Oil Well Cement.
