BS/EN 197-2-2020 pdf download.Cement Part 2 : Assessment and verification of constancy of performance.
5.3.1 InspectIon of the factory and the factory production control
Inspection shall Include checking that any change in the Works’ quality documentation, which is relevant to the factory production control of cement, has been reported within one month of its implementation.
Inspection shall verify that the factory production control complies with the requirements of Clause 4 and has been carried out according to the Works’ quality documentation. All documents being part of the Works’ quality documentation are subject to the Inspection.
The inspections of the factory and the factory production control shall normally be carried out once a year, and the manufacturer shall be informed in advance when an inspection is to be made. Inspection of depots shall normally be carried out at least every three years. If a cement plant operates more than three depots, the frequency of inspections ol the depots may be reduced by mutual agreement.
5.3.2 Evaluation of the results of autocontrol testing of samples
Continuing surveillance, assessment and evaluation of the factory production control includes evaluation of the test results of the manufacturer’s autocontrol testing to check conformity to the statistical AVCP criteria and single result threshold values given in the relevant product specification standard.
The number of evaluations of the results of autocontrol testing of samples shall be at least two per year. The timing of the evaluations should be decided in advance.
The length of the control period for evaluation of the autocontrol test results shall be as specified in the clause entitled Assessment and verification of constancy of performance — AVCP” in the relevant product specification standard, or equal to the initial period (see 5.1) in the case of a newly certified cement.
Each evaluation shall be made on the test results obtained on all autocontrol samples of a given cement, without selection, taken during the control period preceding the date of the evaluation or during the initial period as the case may be.
The evaluation of the test results should exclude any test result accepted as an outlier, e.g. in the case of identified sampling and testing errors.
In the case of managed step changes In product characteristics or in the case of limited production or dispatching runs during the control period, the corresponding data sets may be evaluated separately.
The evaluations may normally be carried out by correspondence and each evaluation shall lead, for the characteristic examined, to a single conclusion in respect of the set of test results as a whole.
It shall be taken into account whether all necessary corrective actions and measures to prevent nonconforming cement from delivery have been taken.
The number of samples taken shall be at least six per year for each cement dispatched continuously. When a cement is not dispatched continuously, this frequency and the point of sampling may be altered by mutual agreement.
The six samples shall be taken as proportional as possible following the actual dispatch of the cement, e.g. two samples from bags and four samples from silos.
For audit-testing of cement dispatched in a depot, at least every three years one sample of each such cement shall be taken at the depot. If a cement plant operates more than three depots, the number of samples for audit-testing to be taken at the depots may be reduced by mutual agreement.
The first sample of a cement to be certified is used for the assessment of the performance of the cement.
The number of samples to be taken during the initial period (see 5.1) shall be at least one per month.
5.4.2 Testing
The mechanical, physical and chemical essential characteristics specified for testing in the clause entitled “Assessment and verification of constancy of performance — AVCP” in the relevant product specification standard shall be determined according to the indicated test methods.
In the case of distributors or importers, where cements were already tested and certified under this document, details are available in CEN/TR 14245.
Each sample taken shall be homogenized and divided Into three sub-samples. The methods used to take and prepare samples shall be in accordance with EN 196-7. One sub-sample shall be retained by the manufacturer for testing and one shall be packed, sealed, clearly labelled and forwarded to the laboratory responsible for audit-testing. The third sub-sample shall be sealed and retained by the manufacturer fora minimum period of three months. It is intended for use if:
a) one of the fIrst two sub-samples is lost, deteriorates or becomes contaminated;
b) further testing is needed in the event of a dispute.
The first two sub-samples are intended for testing at the manufacturer laboratory and at the laboratory responsible for audit-testing, respectively, for the required characteristics as listed in the relevant product specification standard, using the test methods indicated in that standard.
5.4.3 Evaluation of test results
The results obtained shall be evaluated. The procedures specified in Annex A shall be used for the evaluation of the representativeness and accuracy of the 28 day strength results.
The results obtained consist of single values with an uncertainty associated. For evaluation, only the obtained test result shall be considered without taking into account the associated uncertainty of measurement, as this is implicitly covered by the AVCP procedures.BS/EN 197-2-2020 pdf download.