Question

A slump test for concrete is carried out to determine

• A. Workability
• B. Durability
• C. Strength
• D. Water content

Hint:

(“) \textbf{Slump Test:} A field test to measure the consistency and \textbf{workability} of fresh concrete.
(”) \textbf{Workability:} Ease of mixing, placing, compacting, and finishing fresh concrete.
(•) Higher slump value = higher workability (wetter/more fluid mix).
(–) Lower slump value = lower workability (stiffer/drier mix).
(—) It does not directly measure strength, durability, or water content (though it's affected by water content).

Answer 1

The Correct Option is A

The slump test is a common, simple, and widely used field test to assess the consistency or workability of fresh concrete. Workability refers to the ease with which fresh concrete can be mixed, placed, compacted, and finished without segregation or bleeding. It indicates the fluidity or stiffness of the concrete mix. How the slump test is performed: 1. A standard slump cone (a frustum of a cone, typically 300mm high, 100mm top diameter, 200mm bottom diameter) is filled with fresh concrete in layers, each layer being tamped with a standard tamping rod. 2. The cone is then carefully lifted vertically upwards. 3. The unsupported concrete will "slump" (subside) due to gravity. 4. The slump is measured as the difference in height between the top of the slump cone (original height of concrete) and the top of the slumped concrete. Interpretation of slump value:
(Œ) A higher slump value indicates a more fluid, wetter concrete mix (higher workability).
() A lower slump value indicates a stiffer, drier mix (lower workability).
(Ž) Different types of slump (true slump, shear slump, collapse slump) can also indicate the cohesiveness of the mix. The slump test primarily gives an indication of the consistency and workability of the concrete. Let's evaluate the options:
() (a) Workability: This is the primary property assessed by the slump test. It measures the consistency of fresh concrete, which is a key aspect of its workability.
() (b) Durability: Durability refers to the ability of hardened concrete to resist weathering, chemical attack, abrasion, and other deterioration processes over time. Slump test is on fresh concrete and doesn't directly measure durability (though workability can influence compaction, which affects durability).
(‘) (c) Strength (Compressive Strength): Strength is a property of hardened concrete, typically measured by crushing concrete cubes or cylinders at 7, 14, or 28 days. Slump test does not directly measure strength, although there can be an indirect relationship (e.g., very high slump due to excess water can lead to lower strength).
(’) (d) Water content: While the slump value is highly sensitive to the water content of the mix (more water generally means higher slump), the test itself measures consistency/workability, not directly the water content percentage (which is determined by mix design or other tests). Therefore, the slump test for concrete is carried out to determine its Workability. \[ \boxed{\text{Workability}} \]