## Introduction of Cement

Cement is one of the mos**t important engineering construction materials**. It is widely used in the **construction of various Structures**. It is the **key ingredient of the concrete**. Concrete is made by **mixing sand, aggregate, and cement along with water in the fixed proportion**. The Strength of the** Concrete is mainly achieved by the Cemen**t.

In this article, you will get to know about different grades of cement, their properties, and uses.

## Introduction of **OPC**

OPC is one of the most important** types and widely used cement in the Construction Industry**. **OPC Cement full form Ordinary Portland cement. **Ordinary Portland cement (OPC) is the** commonly used cement around the world as a basic ingredient of concrete, mortar, stucco, and non-specialty grout.**

The Ordinary Portland Cement is mainly c**ategorized into three types, which are 33-Grade Cement, 43-Grade Cement, and 53-Grade Cement. **This grade of cement is **classified depending upon the compressive strength of the cement,** which is tested after 28 days.

**Compressive Strength of Cement =( Apply Load / Unit Area)**

The unit of compressive strength is** N/mm ^{2}**

## Which Grade Cement Is Used for Slab

Ordinary Portland cement of **53 Grade** is suitable for all **types of RCC structures** and is mainly used for the **construction of slabs**. Because in the **Construction of slabs, initial and ultimate strength is the major structural requirement.**

The **53 Grade Cement is highly preferred for the construction** of the **structures which require high strength such as the construction of high rise building and bridges.**

## Types of Cement Grades

There are **different grades of cement,** which are specified by **IS 1489: 1991 as** below of **cement grade list.**

**OPC 33 Grade Cement****OPC 43 Grade Cement****OPC 53 Grade cement**

**OPC (Ordinary Portland Cement) 33 Grade Cement**

The Cement, which has **Compressive strength of 33 N/ mm ^{2}** after the 28 days when tested, is known as

**33-Grade Cement.**

Fineness (specific area) of **33 Grade Cement** =** 300 m ^{2}/kg**

**3 days compressive strength**=**16 N/mm**^{2}**7 days compressive strength = 22 N/mm**^{2}**28 days compressive strength = 33 N/mm**^{2}

**Properties of 33-Grade Cement**

- This grade of
**cement has high workability and is mainly used for masonry work and for plastering work**. - The initial strength of
**33 Grade Cement continues to gain even after 28 days**. - The heat of hydration of
**33 Grade Cement is lower as compared to the 43 grade and 53-grade cement.**

**Uses of 33-Grade Cement**

- It is widely
**used in plastering work**. - It is also
**used for the brickwork of walls**. - In the
**tiling work**. - It is generally used for work, which required low
**compressive strength of below M20.**

The Code of reference for** 33-grade cement is IS Code â€“ IS 269: 1989**.

**OPC (Ordinary Portland Cement) 43 Grade Cement**

The Cement, which has **Compressive strength of 43 N/ mm ^{2 }**after the 28 days when tested, is known as

**43-Grade Cement.**Fineness (specific area) of

**43 Grade Cement = 225 m**

^{2}/kg**3 days compressive strength = 23 N/mm**^{2}**7 days compressive strength = 33 N/mm**^{2}**28 days compressive strength = 43 N/mm**^{2}

**Properties of 43-Gradee Cement**

- It has
**low chloride content,**so it**doesnâ€™t cause corrosion of steel reinforcement**. - It gives
**good workability of concrete.** - The initial
**strength of 43 Grade Cement continues to gain even after 28 days**. - The
**heat of hydration of 43 Grade Cement is medium**. - This will give a
**better surface finish to the structures.** - It is
**moderately sulfate resisting.**

**Uses of ****43 ****Grade Cement**

- It is
**used in the preparation of Ready Mix Concrete (RMC).** - It is
**used for PCC and RCC work.** - It is used in the
**construction of RCC bridges.** - For
**Construction of Silos and Chimneys.** - It is used for finishing of all
**types of structures like buildings, bridges, roads, and water retaining**structures. - It is used in
**precast and prestressed concrete.** - It is also
**used in Ship form Construction.** - It is used in the
**construction where a grade of concrete up to M30.**

The Code of reference for **43-Grade Cement is IS Code â€“ IS 8112: 1989.**

**OPC (Ordinary Portland Cement) 53 Grade Cement**

The Cement, which has **Compressive strength of 53 N/ mm ^{2}** after the 28 days when tested, is known as

**53-Grade Cement.**

**Â**Fineness (specific area) of

**53 Grade Cement = 225 m**

^{2}/kg**3 days compressive strength = 27 N/mm**^{2}**7 days compressive strength = 37 N/mm**^{2}**28 days compressive strength = 53 N/mm**^{2}

**Properties of 53 Grade Cement**

- It is a
**Sulphate resisting cement.** - It has
**low chloride content.** - It can be
**used in speedy Construction.** - It
**saves shuttering cost due to early removal.** - The initial
**strength of 53 Grade Cement continues to gain even after 28 days.**

**Uses of 53 Grade Cement**

- It is used the
**construction of concrete sleepers for Railways.** - It is used in
**pre-stressed girders.** - The
**53-Grade Cement achieves early strength**. - It is used in
**industrial buildings roads and runways.** - It is used in the
**construction of RCC bridges and precast concrete.** - Generally used for
**M25 and above concretes.** - It is used in the construction of all
**RCC components like a beam, columns, footings, and slabs.**

The Code of reference for **53-Grade Cement is IS Code â€“ IS 12269: 1987.**

**FAQs About OPC Cement Grades**

**What is OPC cement?**

Ordinary Portland Cement (OPC) is a widely used type of cement in the construction industry. It serves as a fundamental ingredient in concrete, mortar, stucco, and non-specialty grout.

**What are the different grades of OPC cement?**

OPC cement is classified into three main grades: 33-Grade, 43-Grade, and 53-Grade, based on their compressive strength tested after 28 days.

**How is compressive strength measured in OPC cement?**

Compressive strength is measured in N/mmÂ² and indicates the maximum load-bearing capacity of the cement after 28 days of curing.

**Which grade of OPC cement is suitable for slab construction?**

OPC 53 Grade cement is ideal for slab construction due to its high initial and ultimate strength, meeting structural requirements effectively.

**What are the properties of OPC 33-Grade cement?**

OPC 33-Grade cement offers high workability and is commonly used in masonry and plastering work. It has lower heat of hydration compared to higher grades.

**Where is OPC 43-Grade cement typically used?**

OPC 43-Grade cement is preferred for Ready Mix Concrete (RMC), PCC, RCC work, and in the construction of bridges, silos, and chimneys due to its moderate strength and workability.

**Why choose OPC 53-Grade cement?**

OPC 53-Grade cement is sulphate-resistant, has low chloride content, and achieves early strength, making it suitable for rapid construction and critical structural components.

**What are the specific uses of OPC 53-Grade cement?**

OPC 53-Grade cement is utilized in the construction of concrete sleepers for railways, pre-stressed girders, industrial buildings, and all RCC components requiring high strength.

**What are the IS codes for OPC cement grades?**

- OPC 33 Grade: IS 269: 1989
- OPC 43 Grade: IS 8112: 1989
- OPC 53 Grade: IS 12269: 1987

**How does OPC cement contribute to construction quality?**

OPC cement ensures the durability and strength of structures, providing a reliable foundation for various construction projects from residential buildings to infrastructure.