---
title: "7 and 28 day strength of 53 grade OPC"
subject: "Civil Engineering Materials"
chapter: 5
key: "semester_3/civil_engineering_materials:opc-53-grade-strength"
source: https://www.bctengineer.com/q/semester_3/civil_engineering_materials/opc-53-grade-strength
site: BCT Engineering
---

# 7 and 28 day strength of 53 grade OPC

Civil Engineering Materials · Chapter 5: Cement

- Asked in: 2079 Bhadra, 2 marks
- Answer checked by Claude Opus 5.5 (high effort) on 2026-10-14
- Page: https://www.bctengineer.com/q/semester_3/civil_engineering_materials/opc-53-grade-strength
- Whole chapter: https://www.bctengineer.com/md/semester_3/civil_engineering_materials/chapter-5

## Question

What is the 7 and 28 days crushing strength of 53 grade OPC cement?

## Short answer

For 53 grade OPC (IS 12269), the minimum compressive strength of mortar cubes is 37 MPa at 7 days and 53 MPa at 28 days.

## Answer

For 53 grade OPC (IS 12269) the minimum compressive strength of 70.6 mm mortar cubes is:

- **7 days: 37 MPa (N/mm²)**
- **28 days: 53 MPa (N/mm²)**

(The 3-day minimum is 27 MPa.)

## Check yourself

The answer's key points as multiple-choice questions, with the correct option and why.

1. Minimum 28-day strength of 53 grade OPC:
   A. 43 MPa
   B. 37 MPa
   C. 27 MPa
   D. 53 MPa
   Answer: D. Grade number equals the 28-day strength. (Key point: 28-day)

2. Minimum 7-day strength of 53 grade OPC:
   A. 37 MPa
   B. 27 MPa
   C. 53 MPa
   D. 33 MPa
   Answer: A. IS 12269 gives 37 MPa at 7 days. (Key point: 7-day)

3. Minimum 3-day strength of 53 grade OPC:
   A. 23 MPa
   B. 27 MPa
   C. 37 MPa
   D. 33 MPa
   Answer: B. 3-day minimum is 27 MPa; 23 MPa belongs to 43 grade. (Key point: 3-day)

## Related in Civil Engineering Materials

- [Meaning of grade 43 cement](https://www.bctengineer.com/question.md?key=semester_3%2Fcivil_engineering_materials%3Agrade-43-cement) — Civil Engineering Materials, chapter 5
- [Compressive strength test of cement](https://www.bctengineer.com/question.md?key=semester_3%2Fcivil_engineering_materials%3Acement-compressive-strength-test) — Civil Engineering Materials, chapter 5, asked 3×
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- [Harmful ingredients of cement](https://www.bctengineer.com/question.md?key=semester_3%2Fcivil_engineering_materials%3Aharmful-ingredients-opc) — Civil Engineering Materials, chapter 5, asked 2×
- [Clinker compounds strength-time graph](https://www.bctengineer.com/question.md?key=semester_3%2Fcivil_engineering_materials%3Aclinker-strength-graph) — Civil Engineering Materials, chapter 5

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- [Load bearing wall: crushing strength and mortar](https://www.bctengineer.com/question.md?key=semester_5%2Fconcrete_technology_and_masonry_structure%3Awall-250cm-79-5kn-axial) — Concrete Technology and Masonry Structure, chapter 8
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- [Theoretical strength of moist cured concrete (1 kg cement)](https://www.bctengineer.com/question.md?key=semester_5%2Fconcrete_technology_and_masonry_structure%3Atheoretical-strength-1kg-cement) — Concrete Technology and Masonry Structure, chapter 4