Concrete Technology – Correct combined statement about workability and influencing factors Which of the following statements about water content, aggregate characteristics, temperature, and slump/workability of concrete is generally correct in site practice?

Introduction / Context:
Workability summarises how easily concrete can be mixed, placed, and compacted without segregation. It depends on water content, paste volume, aggregate properties, temperature, and admixtures. Recognising how each variable influences slump and cohesiveness is critical for quality control on site.

Given Data / Assumptions:

• No special admixtures unless noted.
• Conventional fine and coarse aggregates.
• Slump test used as the quick indicator.
• Normal ambient conditions are assumed for comparative trends.

Concept / Approach:
Increasing water alone raises the water–cement ratio, which reduces strength and durability; hence to maintain the same water–cement ratio, any water increase must be accompanied by a proportional cement increase. Angular, rough-textured aggregates increase internal friction and reduce flow. Larger maximum size reduces total surface area for a given volume, often improving workability for the same paste content. Higher temperature accelerates setting and increases evaporation, lowering measured slump if other parameters are unchanged.

Step-by-Step Solution:
Relate workability to water and paste: more water → higher slump → to maintain w/c, cement must also increase.Assess aggregate shape/texture: angular and rough → lower workability due to higher interparticle friction.Consider size effect: larger aggregates → less surface area → less paste demand → improved workability (within limits).Temperature trend: higher temperature → faster stiffening → lower slump for the same mix.

Verification / Alternative check:
These trends are widely reflected in mix design guides and site QC notes: adjust by admixtures rather than uncontrolled water addition; choose aggregate grading and size to balance finishability and pumpability.

Why Other Options Are Wrong:
Each statement (a)–(d) is individually correct; therefore the comprehensive choice is “All of the above”.

Common Pitfalls:
Attempting to fix low slump by adding water alone; this compromises strength. Also, pushing aggregate size too large may harm finishability or cause blocking in congested reinforcement.

Final Answer:
All of the above