---
title: "Soundness and specific heat capacity"
subject: "Civil Engineering Materials"
chapter: 1
key: "semester_3/civil_engineering_materials:property-soundness-spec-heat"
source: https://www.bctengineer.com/q/semester_3/civil_engineering_materials/property-soundness-spec-heat
site: BCT Engineering
---

# Soundness and specific heat capacity

Civil Engineering Materials · Chapter 1: Introduction to Civil Engineering Material

- Asked in: 2072 Chaitra, 0.5 marks; 2076 Asoj, 0.5 marks (asked 2 times)
- Video: [Soundness of cement](https://www.youtube.com/watch?v=Nw8ROwxYQME) — Mounika Ganta
- Answer checked by Claude Opus 5.5 (high effort) on 2026-10-14
- Page: https://www.bctengineer.com/q/semester_3/civil_engineering_materials/property-soundness-spec-heat
- Whole chapter: https://www.bctengineer.com/md/semester_3/civil_engineering_materials/chapter-1

## Question

Define soundness and specific heat capacity as properties of materials.

## Short answer

Soundness is resistance to volume change, cracking or expansion after setting, tested by Le Chatelier and autoclave tests for cement and sulphate tests for aggregate. Specific heat capacity is the heat required to raise unit mass by one degree, in J/(kg·K), important for thermal storage.

## Answer

#### Soundness
**Soundness** is the ability of a material (mainly cement, lime or aggregate) to resist volume change, cracking or expansion after setting. Unsound cement expands because of free lime or magnesia. For cement, soundness is tested by the Le Chatelier and autoclave tests; for aggregate, by the sodium or magnesium sulphate soundness test.

#### Specific heat capacity
**Specific heat capacity** is the quantity of heat required to raise the temperature of unit mass of a material by one degree. Its unit is J/(kg·K).

$$
c = \frac{Q}{m\,\Delta T}
$$

Materials with high heat capacity (water, and massive concrete or brick walls) heat up and cool down slowly, so they are good for thermal storage.

## Check yourself

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

1. Soundness is the ability to resist
   A. scratching
   B. volume change or expansion after setting
   C. heat flow
   D. water passage
   Answer: B. Unsound cement expands after setting. (Key point: Soundness)

2. Unsound cement expands because of
   A. excess gypsum only
   B. too much water
   C. free lime or magnesia
   D. fine sand
   Answer: C. Free lime or magnesia causes expansion. (Key point: Unsound cause)

3. Specific heat capacity is the heat needed to raise unit mass by
   A. ten degrees
   B. one metre
   C. one second
   D. one degree
   Answer: D. c = Q/(m dT), unit J/(kg K). (Key point: Specific heat)

## Related in Civil Engineering Materials

- [Important properties of civil engineering materials](https://www.bctengineer.com/question.md?key=semester_3%2Fcivil_engineering_materials%3Aimportant-properties-civil-materials) — Civil Engineering Materials, chapter 1, asked 8×
- [Properties of pozzolanic materials](https://www.bctengineer.com/question.md?key=semester_3%2Fcivil_engineering_materials%3Aproperties-pozzolanic-materials) — Civil Engineering Materials, chapter 4
- [Soundness test of cement and procedure](https://www.bctengineer.com/question.md?key=semester_3%2Fcivil_engineering_materials%3Acement-soundness-test-procedure) — Civil Engineering Materials, chapter 5
- [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
- [Principle of heat treatment of metal](https://www.bctengineer.com/question.md?key=semester_3%2Fcivil_engineering_materials%3Aheat-treatment-principle) — Civil Engineering Materials, chapter 8, asked 5×
- [Purposes of heat treatment](https://www.bctengineer.com/question.md?key=semester_3%2Fcivil_engineering_materials%3Aheat-treatment-objectives) — Civil Engineering Materials, chapter 8, asked 5×

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