---
title: "Soundness test of cement and procedure"
subject: "Civil Engineering Materials"
chapter: 5
key: "semester_3/civil_engineering_materials:cement-soundness-test-procedure"
source: https://www.bctengineer.com/q/semester_3/civil_engineering_materials/cement-soundness-test-procedure
site: BCT Engineering
---

# Soundness test of cement and procedure

Civil Engineering Materials · Chapter 5: Cement

- Asked in: 2080 Bhadra, 2+3 marks
- Video: [Soundness Test of Cement by Le-Chatelier Method | Cement Test | Learning Civil Technology](https://www.youtube.com/watch?v=P8VBpFuXnXQ) — L&T - Learning Technology
- Answer checked by Claude Opus 5.5 (high effort) on 2026-10-14
- Page: https://www.bctengineer.com/q/semester_3/civil_engineering_materials/cement-soundness-test-procedure
- Whole chapter: https://www.bctengineer.com/md/semester_3/civil_engineering_materials/chapter-5

## Question

Write down the importance of the soundness test of cement and its stepwise testing procedure followed in laboratory.

## Short answer

Soundness ensures no harmful expansion after setting. Le Chatelier test: mix 100 g cement with 0.78P water, fill split cylinder mould, store underwater 24 h, measure pointer distance A. Boil 3 h, cool, measure B. Expansion = B−A must not exceed 10 mm for OPC.

## Answer

#### Importance
Soundness means the ability of the hardened cement paste to keep its volume without expansion. Unsound cement (with excess free lime, magnesia or sulphates) expands after setting and causes cracking, distortion and failure of concrete. So the test makes sure the cement is safe before use.

#### Le Chatelier test (IS 4031 Part 3)
1. Mix 100 g of cement with 0.78 P of water (P = standard consistency), gauging well.
2. Place the Le Chatelier mould (a split brass cylinder 30 mm in diameter and 30 mm high, with two indicator arms 165 mm long) on a glass plate and fill it with the paste.
3. Cover it with another glass plate, put a small weight on top and immediately submerge the whole assembly in water at 27 ± 2 C for 24 hours.
4. Take it out and measure the distance between the pointer ends (A) to the nearest 0.5 mm.
5. Submerge the mould in water again, bring the water to boiling in 25-30 minutes and keep it boiling for 3 hours.
6. Let the mould cool, and measure the distance again (B).
7. Expansion = B - A. For OPC it must not exceed **10 mm**; if it does, the cement may be retested after aerating it for 7 days.

The autoclave test (expansion limit 0.8%) is also used, mainly for magnesia.

## Check yourself

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

1. Soundness of cement means:
   A. High early strength
   B. Hardened paste keeps its volume without expansion
   C. Fast setting
   D. Fine grinding
   Answer: B. Unsound cement expands and cracks. (Key point: Soundness meaning)

2. Le Chatelier test uses 100 g cement with water:
   A. 0.85 P
   B. P/4 + 3
   C. 0.78 P
   D. 26%
   Answer: C. Mixed with 0.78 P. (Key point: Le Chatelier water)

3. After 24 h in the humid chamber, the mould is:
   A. Dried and weighed
   B. Crushed
   C. Autoclaved at once
   D. Measured, then boiled for 3 h and measured again
   Answer: D. Expansion = B - A. (Key point: Procedure)

4. Maximum Le Chatelier expansion for OPC:
   A. 10 mm
   B. 5 mm
   C. 0.8 mm
   D. 20 mm
   Answer: A. If exceeded, retest after aeration for 7 days. (Key point: Limit)

## Related in Civil Engineering Materials

- [Why soundness test of cement](https://www.bctengineer.com/question.md?key=semester_3%2Fcivil_engineering_materials%3Awhy-soundness-test-cement) — Civil Engineering Materials, chapter 5
- [Stepwise preparation of cement mortar](https://www.bctengineer.com/question.md?key=semester_3%2Fcivil_engineering_materials%3Astepwise-preparing-cement-mortar) — Civil Engineering Materials, chapter 6, asked 4×
- [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×
- [Consistency test of cement](https://www.bctengineer.com/question.md?key=semester_3%2Fcivil_engineering_materials%3Acement-consistency-test) — Civil Engineering Materials, chapter 5
- [Standard tests of cement](https://www.bctengineer.com/question.md?key=semester_3%2Fcivil_engineering_materials%3Astandard-tests-cement-field-lab) — Civil Engineering Materials, chapter 5

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