Issues concerning procedures for production of bituminous mixtures under EN 13108-21 and specified tolerances are discussed in Chapter 14.
9.5.2 Other Examples of Production Control
Some brief examples from around the world include
• In some countries, the accuracy of stabilizer dosage is ±10% of its mass as determined in a laboratory formula.
• If binder viscosity is the basis for establishing the mixing temperature of a binder and aggregate, some specifications may quote a permissible deviation from that temperature (e. g., ±10°C).
• In most countries, the permissible deviation of a mixture gradation and the content of binder depends on the number of tested samples.
• Some regulations provide clauses permitting a situation in which the gradation curve of a produced mix, considering given deviations, may deviate outside the area of the gradation envelope (between the so-called upper and lower limit curves).
