Cement properties – identify the INCORRECT definition

Introduction / Context:
Terminology precision is essential in material specifications. Several cement properties have similar-sounding names but very different meanings and tests. This question challenges recognition of the incorrect definition.

Given Data / Assumptions:

• Standard properties: fineness, setting, soundness, heat of hydration.
• We must spot the incorrect statement.

Concept / Approach:
Fineness quantifies particle size (degree of grinding). Setting describes the stiffening process culminating in hardening. Heat of hydration is the thermal energy released during hydration reactions. “Soundness,” however, does not relate to acoustic transmission; it means volume stability—cement paste should not undergo excessive late expansion after setting.

Step-by-Step Solution:
Validate (a), (b), (d) → all correct standard definitions.Identify (c) as incorrect: soundness concerns freedom from delayed expansion (e.g., due to free lime or MgO), not acoustics.Therefore, select (c) as the incorrect definition.

Verification / Alternative check:
Soundness is assessed by Le Chatelier or autoclave expansion tests, explicitly targeting volumetric stability.

Why Other Options Are Wrong:
They are correctly worded and reflect standard textbook meanings.

Common Pitfalls:
Confusing “soundness” with “sound insulation” of concrete elements; they are unrelated topics.

Final Answer:
Soundness is the property by virtue of which cement does not allow transmission of sound is incorrect.