What is the maximum allowable percentage of water-soluble chlorine ion by weight of cement?

The correct answer indicates that the maximum allowable percentage of water-soluble chlorine ion by weight of cement is 0.06%. This figure is significant in the context of construction materials because the presence of chlorides in cement can lead to detrimental effects, especially in reinforced concrete. Chloride ions can promote corrosion of steel reinforcement, which compromises the durability and longevity of concrete structures.

The limit of 0.06% serves as a protective guideline to ensure that the integrity of concrete is maintained over time. Limits on chlorides are particularly critical in environments where concrete is exposed to harsh conditions, such as coastal areas or places where de-icing salts are used.

The other listed percentages do not reflect the accepted industry maximums based on recognized standards for cement composition. The value of 0.01% or lower could potentially be too stringent, potentially affecting the availability and economic viability of certain cement types, while values higher than 0.06% risk compromising structural integrity through enhanced corrosion rates. Thus, 0.06% is seen as a balanced limit that helps ensure both performance and safety in concrete applications.