Concrete defects — outcomes commonly caused by segregation Segregation of fresh concrete (coarse aggregate separating from mortar) commonly leads to which of the following defects after setting/hardening?

Introduction / Context:Segregation occurs when components of fresh concrete separate due to improper proportioning, excessive vibration, high drop heights, or inadequate cohesiveness. The resulting non-uniformity compromises durability, strength, and appearance.

Given Data / Assumptions:

• Conventional vibrated concrete.
• Poor handling practices or unstable mixes (e.g., very low fines, high slump without VMA).
• Normal placement conditions with avoidable errors.

Concept / Approach:

When segregation happens, mortar may run off and coarse aggregate clusters, leaving voids and creating honeycombing; stratified layers form, and surface finish suffers, producing scaling and sand streaks. Preventing segregation maintains designed gradation through the section and ensures proper paste coating and cohesion.

Step-by-Step Solution:

Verification / Alternative check:

Site QA records link high drop placements and over-vibration with pronounced honeycombing and laitance layers, validating the cause–effect relation.

Why Other Options Are Wrong:

• Each individual defect may occur, but segregation can cause all of them simultaneously; hence the comprehensive choice is correct.

Common Pitfalls:

• Confusing bleeding (water rising) with segregation; both can co-occur but are distinct.
• Ignoring the role of appropriate grading and admixtures in cohesion.

Final Answer:

All of the above.