Mix Water – typical water required per 50 kg bag of cement for a workable concrete Approximately how much water (by mass) is required per 50 kg bag of cement to produce a normal workable concrete mix (typical site value without admixtures)?

Introduction / Context:
The water content of concrete governs workability and, through the water–cement ratio, strongly influences strength and durability. On many sites, a rule-of-thumb water amount per cement bag is quoted for ordinary, hand-placed mixes when no admixtures are used.

Given Data / Assumptions:

• Cement bag = 50 kg.
• “Normal workable” mix for general RCC elements without pumping.
• No chemical water-reducers; aggregates in SSD or corrections applied.

Concept / Approach:
Typical water–cement ratios for general-purpose concrete range from about 0.45 to 0.60 depending on strength grade and workability requirements. Taking a mid-range w/c of ~0.55 yields water per bag of approximately 0.55 * 50 kg = 27.5 kg, commonly rounded to 28 kg in practice.

Step-by-Step Solution:
Assume w/c suitable for normal placement ≈ 0.55.Compute water per bag: 0.55 * 50 = 27.5 kg.Round to the nearest kilogram in the given options → 28 kg.

Verification / Alternative check:
For the minimum water required for complete hydration only, about 0.23 * 50 ≈ 11.5 kg is needed, but additional water is essential for workability; hence the higher practical value around 28 kg.

Why Other Options Are Wrong:

• 7, 14, 21 kg correspond to very low w/c (0.14–0.42) and would be too stiff without plasticizers.
• 35 kg corresponds to w/c = 0.70, excessively high and detrimental to strength and durability.

Common Pitfalls:
Adding water at site to “restore” slump; this raises w/c and reduces strength. Instead, adjust with admixtures or re-balance aggregate moisture.

Final Answer:
28 kg