This question asks to identify the true statement(s) concerning concrete properties, particularly focusing on the role of water.

Concrete Water Facts True Statements

Let's analyze each statement:

• Statement 1: The quality of water governs the strength of concrete

  This statement is true. Impurities in water (like salts, acids, organic matter) can interfere with the cement hydration process, affect setting time, and potentially cause durability issues, thereby influencing the final strength and performance of the concrete.

• Statement 2: The quantity of water required for concreting, depends upon the grading of aggregate and method of compaction

  This statement is true. The water required is determined by the water-cement ratio needed for strength, but the actual amount needed for workability depends on factors like the aggregate's size distribution (grading), shape, texture, and the compaction method. Well-graded aggregates require less water than poorly-graded ones for the same workability.

• Statement 3: 10% excess of water reduces the strength of concrete by 15%

  This statement is generally considered true and represents a common understanding in concrete technology. Adding excess water increases the water-cement ratio, leading to more voids after hardening and significantly reducing the concrete's compressive strength and durability.

Conclusion on Concrete Statements

Since statements 1, 2, and 3 are all factually correct regarding concrete properties and the influence of water, the statement that encompasses all of them must be the true one.

• Statement 4: All option are correct

  As established above, statements 1, 2, and 3 are all true. Therefore, this option is correct.

The correct choice is the one that affirms all the individual correct statements.