Lime concrete in building works — typical areas of application Lime concrete is generally preferred and specified for:

Introduction / Context:
Lime concrete, a mix using lime as the binder instead of Portland cement, has long been used in traditional construction for foundations and floor bases. Its workability, compatibility with masonry, and breathability suit heritage and low-strength applications.

Given Data / Assumptions:

• Lime concrete uses fat/hydraulic lime with aggregates.
• Loads are moderate (e.g., masonry walls, ground-bearing floors).
• Moisture movement and vapor permeability are desirable in heritage structures.

Concept / Approach:
Lime binds more slowly but offers flexibility and reduced shrinkage. In foundations under masonry, it provides a compatible substrate. As a ground floor base or fill, lime concrete helps moisture regulation, making it appropriate for traditional floors beneath toppings or stone slabs.

Step-by-Step Solution:
Identify typical use cases from historic practice and modern conservation.Confirm suitability for wall foundations and ground floors where high early strength is not critical.Select the combined option reflecting both common applications.

Verification / Alternative check:
Conservation guidelines frequently specify lime concrete under masonry and as base layers for breathable floors, confirming both uses.

Why Other Options Are Wrong:
Choosing only one application understates lime concrete’s range; rejecting both ignores centuries of practice.

Common Pitfalls:
Expecting cement-like early strength; inadequate curing time may cause surface weakness if not planned.

Final Answer:
Both (a) and (b)