BS EN 13286-1:2021 pdf free download – Unbound and hydraulically bound mixtures Part 1: Test methods for laboratory reference density and water content – Introduction, general requirements and sampling.
A.1 General
This annex describes methods for:
— obtaining samples of unbound and hydraulically bound mixtures after manufacture or at the point of delivery;
— reducing the size of the sample prior to submission to a laboratory;
— reducing the sample submitted to the laboratory to test portion size.
NOTE 1 The methods described are based on manual procedures. Mechanical devices can be used, subject to the criteria for mechanical sampling apparatus set out in EN 932-1.
NOTE 2 Where necessary, the method of dividing the test portion into a number of test specimens is given in the relevant test method.
A.2 Principle
A bulk sample is obtained that is representative of the average properties of the batch. NOTE Principles of sampling and sample reduction are given in EN 932-1.
A.3 Bulk sample size and number of increments
The total size of the bulk sample shall be at least twice the quantity estimated as being required for the tests to be carried out, with a minimum mass of 10 kg. The bulk sample shall consist of at least five increments.
NOTE 1 The use of twice the required quantity allows for repeated tests to resolve anomalous or disputed test results.
NOTE 2 Guidance on the amount of mixture required for each test is given In Table A.1. The values given are based on a loose bulk density of 2,0 Mg/m3.
A.4 Sampling plan
The sampling plan shall conform to the requirements in EN 932-1.
The sampler should be aware that all mixtures are prone to segregation. Mixtures with a value of upper, D, sieve size greater than 20 mm or which contain aggregates of differing particle densities are particularly liable to segregation.
NOTE The sampling plan can include details of the number of samples to be taken and/or the frequency of sampling. This information can be defined in a system olfactory production control.
A.5 Apparatus
All apparatus shall conform to the requirements in EN 932-1.
A.8 Test portion preparation
If it is necessary to reduce the size of the laboratory sample to produce one or more test portions, the procedures described in EN 932-2 shall be used.
A.9 Marking, packaging and dispatch
Marking, packaging and dispatch of the samples shall conform to the requirements in EN 932-1.
A.10 Sampling report
The sampling report shall conform to the requirements in EN 932-1.
The sampling report shall refer to this document.
If appropriate, the sampling report may include
a) ambient temperature and weather conditions;
b) temperature of the sample.