Effect of water content on fresh concrete: identify the correct statements describing how insufficient or excess mixing water changes workability and quality

Introduction / Context:Water content directly controls the water–cement ratio and cohesion of fresh concrete. Deviations from the optimum affect placement quality and hardened strength.

Given Data / Assumptions:

• Conventional Portland cement concrete.
• Standard placement methods with or without vibration.

Concept / Approach:Too little water yields stiff, harsh, unworkable mixes that are difficult to compact; too much water dilutes paste, causing segregation of coarse aggregate and bleeding of water to the surface, creating weak, porous concrete.

Step-by-Step Solution:Relate W/C ratio to cohesion and paste volume.Identify effects of low water: harshness and poor workability.Identify effects of high water: segregation and bleeding.All listed statements are therefore correct.

Verification / Alternative check:IS 456 and ACI 211 highlight optimum W/C ranges; exceeding them leads to the described defects.

Why Other Options Are Wrong:

• No single statement is false; each captures a real defect due to improper water content.

Common Pitfalls:

• Adding water on site to 'improve' slump without adjusting cement content, reducing long-term strength.

Final Answer:All the above