## Introduction of Cement

Cement is the foremost vital module of engineering construction jobs. Concrete is created by blending sand, aggregate, cement & water at a specific proportion. The brawn of Concrete is especially attained by the brawn of Cement, i.e. Concrete brawn is directly proportional to cement brawn which in turn decides the brawn of structure.

Cement is accessible in several grades. The cement grade refers to the cement compressive strength, which implies how much strength cement possesses or bears. These cement grades are tested in a standard cube after 28 days of curing. As the cement grade ameliorates, its brawn surges. Compressive strength is measured in Mega-pascal (Mpa) or in N/mm2.

## Introduction of OPC

Ordinary Portland cement (OPC) is the most utilized cement within the world for generating concrete, mortar, stucco, & non-specialty grouts. OPC has 3 grades supported its brawn- 33, 43 & 53 grade. OPC is prepared by grinding together OPC Clinker (95â€“97%) & gypsum (3â€“5%). Compressive Strength of Cement = Applied Load / Unit Area.

## Types of Cement Grades

- OPC Grade Cement-
- PPC Grade Cement-
- PSC Grade Cement-
- Super Grade Cement-

### 1. OPC Grade Cement-

OPC means Ordinary hydraulic cement could be fully automated & dried during preparation.

### 2. PPC Grade Cement-

PPC means Portland Pozzolana Cement could be fully automated & dried during the preparation & contains gypsum & pozzolanic substances. This cement is employed especially in dams & bridges where more resistivity is required.

### 3. PSC Grade Cement-

PSC means Portland Slag Cement is prepared by inter-grinding inÂ Portland cementÂ clinker.

### 4. Super Grade Cement-

- Super grade cement possesses good strength.Â This kindÂ of advanced cement is generatedÂ by limited companies, such as Ultratech, Ramco cement.
- Difference between 33, 43 & 53 Grade Cement.
- According to Indian Codes, OPC Cement can be categorized into 3 Grades,Â OPC 33, 43 & 53 Grades.

## Difference Between 33, 43 & 53 Grade Cement

**OPC 33 Grade Cement**

This grade of cement is employed for a general construction job. Due to the rising supply of finer grades of cement, utilization of 33-grade cement has gradually been declined. Of late, it is rarely found.

**Properties of OPC 33 Grade Cement**

##### Compression Strength:

It achieves a compression strength of 33 megapascals in 28 days of curing.

##### Initial Strength:

- It achieves 16 mph in 3 days, 22 mph in 7 days.
- The Cement, which possesses Compressive strength of 33 N/ mm
^{2}after the 28 days when tested (according toÂ Indian Standards at Standard Conditions),Â is namedÂ as 33-Grade Cement. - Fineness = 300 m2/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} - It possesses a high range of workability & is principally utilized for masonry & plastering jobs.
- Hydration heat is lower than other grades.

#### Price of **OPC 33 Grade Cement**

The cost price of 33-grade cement is much lower than 43-grade cement.

#### Uses & Application of **OPC 33 Grade Cement**

- VastlyÂ employed inÂ plastering job in single-storeyed houses.
- Additionally utilized for the brickwork of walls & tiling jobs.
- Generally utilized for jobs of low compressive strength (Concrete Grade < M20).
- Code of reference- IS Code â€“ IS 269: 1989.

### OPC 43 Grade Cement

- OPC 43 is employed for RCC construction, where a grade of concrete is up to M30.
- This cementÂ is employedÂ for plain concrete work & plastering works where setting timeÂ isn’tÂ an essential issue.
- ItÂ may be an affordable choice over OPC 53 grade cement.
- It additionally has better grinding of clinkers but is inferior to OPC 53.
- This causes it to possess a sloth gain in strength &, additionally, comparative magnesium lack by a difference of -0.01%, which in turn affects the hydration heat.

#### Properties of **OPC 43 Grade Cement**

##### Compression Strength:

It achieves a compression strength of 43 mph (megapascals) in 28 days of curing.

##### Initial Strength:

- It achieves 23 mpa in 3 days, 33 mpa in 7 days.
- TheÂ Cement,Â which hasÂ Compressive strength of 43 N/ mm
^{2Â }after the 28 days when tested (according to Indian Standards under standard conditions), is named 43-Grade Cement. - Fineness = 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} - It’s low in chloride content. Hence it doesnâ€™t cause corrosion of steel reinforcement.
- It provides good workability of concrete.
- The initial strength of 43 Grade Cement remainsÂ even after 28 days.
- The hydration heat of 43 Grade Cement is medium.
- This supplies aÂ better surface finish to the structures.
- It is moderately sulfate resisting.

#### Price ofÂ **OPC 43 Grade Cement**

The cost price of 43-grade cement is beyond 33-grade but not up to 53-grade cement.

#### Uses of **OPC 43 Grade Cement**

- Utilized for preparation of Ready Mix Concrete (RMC).
- Utilized for PCC & RCC work (Concrete Grade upto M-30).
- Employed in the development of RCC bridges.
- For the Construction of Silos & Chimneys, itâ€™s additionally utilized.
- Utilized for finishing of buildings, bridges, roads, & water retaining structures.
- Employed inÂ precast items (blocks, tiles, sheets, pipes etc.) & prestressed concrete.
- Employed for non-structural jobs like plastering, flooring & so on.
- AdditionallyÂ utilized inÂ Ship Construction.
- Utilized in developmentÂ (concrete upto M30).
- General Civil Engineering construction jobs.
- Utilized in Asbestos products like sheets & pipes.
- Employed in Non-structural works like plastering, flooring etc.
- Code of reference- IS Code â€“ IS 8112: 1989.

### OPC 53 Grade Cement

- OPC 53Â is employedÂ if greater strength concrete at affordable cement content is required.
- It possesses a quick setting time with respect to 43-grade cement.
- It’s principally utilized for structural purposes, as in reinforced cement concrete.
- It possesses maximum grinding of clinkers property & it is better than grade 43.
- The hydration heat, however, is further supported by magnesium strength which is 6.01% in OPC 53, only 0.01% > OPC 43.

#### Properties of OPC 53 Grade Cement

##### Compression Strength:

It achieves a compression strength of 53 mpa (megapascals) in 28 days of curing.

##### Initial Strength:

- It possesses a quick setting compared to 43-grade cement. 33 Grade achieves 27 mpa in 3 days, 37 mpa in 7 days.
- The Cement, which has Compressive strength of 53 N/mm
^{2} - after the 28 days when tested. (according to Indian Standards at Standard Conditions), is named as 53-Grade Cement.
- Fineness of 53 Grade Cement = 225 m2/kg.
- 3 days compressive strength = 27 N/mm2.
- 7 days compressive strength = 37 N/mm
^{2} - 28 days compressive strength = 53 N/mm
^{2} - It’sÂ a Sulphate resisting cement.
- It’sÂ low in chloride content.
- Low shuttering costÂ due toÂ early removal.

#### Price of OPC 53 Grade Cement

The cost price of 53-grade cement is loftier than 33 & 43-grade cement.

#### Uses of OPC 53 Grade Cement

- Utilized in makingÂ of Railway Sleepers.
- Utilized inÂ pre-stressed girders.
- It achieves early brawn.
- Utilized inÂ industrial buildings blocks, roads, runways & bridges.
- Employed in makingÂ of RCC (Concrete Grade >M-25) bridges & prestressed & precast concrete items like blocks, tiles.
- Employed for M25 (& >M25) concrete grades.
- Utilized in the development of all RCC components like a beam, columns, footings & slabs.
- Code of reference- IS Code â€“ IS 12269: 1987.

S.No. |
Grade of Cement |
Compressive Strength in 3 days (N/mm^{2}) |
Compressive Strength in 7 days (N/mm^{2}) |
Compressive Strength in 28 days (N/mm^{2}) |

1. | 33grade | Â Â Â Â Â 16 | Â Â Â Â Â Â 23 | Â Â Â Â Â 33 |

2. | 43grade | Â Â Â Â Â 22 | Â Â Â Â Â Â 33 | Â Â Â 43 |

3. | 53grade | Â Â Â Â Â 33 | Â Â Â Â Â 43 | Â Â Â Â Â 53 |

## Conclusion

With the pop up of new technologies, the manufacturing of high strength cement became gradually possible. Of late, there are only a few Companies that prepare 33-grade cement & 43-grade cement. When 33 & 43-grade cement isn’t obtainable, Portland pozzolana cement (affordable) can be selected.

**Frequently Asked Questions (FAQs)**

### What Are the Different Grades of Cement Available?

Cement is typically categorized into grades such as OPC 33, OPC 43, and OPC 53 based on their compressive strength.

### How is cement grade determined?

Cement grade is determined by its compressive strength, measured in megapascals (MPa), after 28 days of curing.

### What Is Opc Cement?

Ordinary Portland Cement (OPC) is the most commonly used cement in construction, known for its versatility in various applications including concrete, mortar, and stucco.

### What are the differences between OPC 33, OPC 43, and OPC 53 grades?

OPC 33 is suitable for general construction, OPC 43 is used for RCC (Reinforced Cement Concrete) up to grade M30, while OPC 53 is preferred for structural purposes requiring higher strength.

### What Are the Applications of Opc 33 Grade Cement?

OPC 33 grade cement is typically used for plastering, masonry, and low-strength concrete applications such as in single-storey houses.

### When Should I Use Opc 43 Grade Cement?

OPC 43 grade cement is suitable for RCC work up to grade M30, precast items, and construction where moderate strength concrete is required.

### What Are the Advantages of Opc 53 Grade Cement?

OPC 53 grade cement offers higher compressive strength, quick setting time, and is suitable for structures requiring high strength like bridges, industrial buildings, and prestressed concrete.

### Which Cement Grade Is Cost-Effective?

OPC 33 grade cement is generally more cost-effective compared to OPC 43 and OPC 53 grades.

### Can Opc Grades Be Substituted with Other Types of Cement?

Yes, depending on specific project requirements, alternatives like Portland Pozzolana Cement (PPC) can be used, especially where higher resistance to corrosion or special properties are needed.

### What Standards Govern the Production and Use of Opc Cement in India?

OPC cement production and use in India are governed by Indian Standards, notably IS 269, IS 8112, and IS 12269, which specify quality requirements and testing methods.