Brick corbels: Which of the following statements is NOT correct for the design and construction of brick corbels?

Introduction / Context:
A brick corbel is a stepped projection formed by successive courses, used to support beams, projections, or decorative features. Safe proportioning and correct bonding are essential to avoid shear failure at the offsets and to ensure durability under service loads.

Given Data / Assumptions:

• Corbels are constructed by stepped projections of masonry courses.
• Wall thickness limits the safe total projection.
• Per-course projection limits help maintain stability and bond.

Concept / Approach:
Good practice limits the total projection to not more than the supporting wall thickness and keeps each step modest (about one-quarter brick) to maintain bonding and shear resistance. For heavy concentrated loads, continuous, well-bonded corbels or alternative structural supports (e.g., reinforced concrete brackets, steel shelves) are preferred; discontinuous corbels provide poor load sharing and stress concentrations.

Step-by-Step Solution:
Evaluate (a): widely accepted limit; helps avoid overstressing → correct.Evaluate (b): limiting per-course projection improves stability → correct.Evaluate (c): recommending discontinuous corbels for heavy concentrated loads is unsafe → NOT correct.Evaluate (d): stretcher-bond layouts are common where units are stepped; headers may be introduced per detail; statement is generally acceptable.Therefore, (c) is the incorrect activity.

Verification / Alternative check:
Construction handbooks caution against excessive offset and emphasize continuous, well-bonded arrangements for significant loads; discontinuous projections should be avoided for heavy point loads.

Why Other Options Are Wrong:
(a) and (b) reflect standard proportioning limits.(d) and (e) describe common bonding and jointing practices to enhance performance.

Common Pitfalls:
Over-projecting per course; poor bonding at offsets; attempting to support heavy beams on isolated corbel blocks without proper continuity or reinforcement.

Final Answer:
Discontinuous (separate) corbels are preferred for carrying heavy concentrated loads is NOT correct.