Concrete testing — the slump test of fresh concrete is primarily used to assess which property? Pick the most appropriate parameter.

Introduction / Context:
Before placement, concrete must be workable enough to be transported, placed, compacted, and finished without segregation or excessive bleeding. The slump test is a quick field indicator of consistency/workability and is widely used for quality control on site. This question ensures you identify the property directly evaluated by the slump test.

Given Data / Assumptions:

• Standard Abrams cone, standard rodding and lift procedure.
• Measurement is vertical subsidence (slump) in millimetres.
• Mixtures may vary in water, admixtures, and aggregate grading.

Concept / Approach:
Slump is an empirical measure of the ease of flow/consistency of fresh concrete. While water content influences slump, the test does not directly measure strength, durability, or precise water content. It provides a comparative index of workability for mixes of similar composition.

Step-by-Step Solution:

Verification / Alternative check:
Standards (e.g., IS/ASTM) define slump classes for different placement methods, confirming its role as a workability indicator.

Why Other Options Are Wrong:

• Strength: Determined on hardened specimens (compression tests).
• Durability: Multi-factor property inferred from permeability, cover, mix design—not measured by slump.
• Water content: Influences slump but is not measured directly.

Common Pitfalls:
Using slump to compare dissimilar mixes; ignoring temperature and admixture effects on workability.

Final Answer:
Workability