Mortars and concretes in building works: identify the incorrect statement among the following common site practices and material properties.

Introduction / Context:
Selecting proper binders and mixes for masonry, plaster, and concrete is a core site skill. Some statements are true generalizations; others conflict with standard practice. This item asks you to find the incorrect one.

Given Data / Assumptions:

• Lime mortars (fat/hydraulic), surkhi (brick powder) as pozzolanic additive.
• Pointing is typically a hard, weather-resistant finish.
• Cold-weather concreting favors faster strength gain.

Concept / Approach:
Good practice requires slaking lime prior to mortar preparation for uniformity and workability. Adding cement to lime mortar yields cement–lime mortar with increased hydraulic set and strength. In cold weather, high early strength concrete/cement helps reach target strengths sooner. Conversely, lime–surkhi mortar is more suited for general masonry/plaster; pointing usually uses stronger cement mortar for weathering resistance, not lime–surkhi.

Step-by-Step Solution:
Validate each statement against common practice.Identify that “Lime surkhi mortar is used for pointing the walls” is atypical/incorrect.Select this as the incorrect option.

Verification / Alternative check:
Measurement and specification handbooks list cement mortar (e.g., 1:3 or 1:4) for pointing; lime–surkhi rarely meets durability expectations for exposed pointing.

Why Other Options Are Wrong:

• (a) Correct: slaking is essential.
• (b) Correct: accelerates strength gain in cold weather practices.
• (c) Correct: cement addition improves hydraulic properties and strength.

Common Pitfalls:

• Assuming any mortar suits pointing; exposure demands strong, dense mixes.

Final Answer:
Lime surkhi mortar is used for pointing the walls