How accurate must balances be for fine aggregate according to C136?

The requirement for balances used in the testing of fine aggregate, as specified in ASTM C136, is that they must be readable to the nearest 0.1 gram or 0.1%. This level of accuracy is essential because fine aggregates are often used in precise applications where small variances can significantly impact the properties of the concrete or other mixtures being prepared. Having a balance that is capable of measuring to this degree ensures that the amounts of materials being combined are accurate, leading to consistent quality in the resulting construction materials.

Balances that do not meet this specification may introduce errors in the measurement of aggregates, which can affect the performance of the concrete in terms of strength, durability, and workability. Therefore, readability to the nearest 0.1 gram is critical for maintaining the integrity of construction projects.