BS EN 13383-2 pdf free download
BS EN 13383-2-2019 pdf free download.Armourstone Part 2: Test methods.
4.4.2 Apparatus for sample reduction and transport
4.4.2.1 A floor area, upon which samples can be deposited and tested. The floor shall be sufficiently clean and close-textured to be able to distinguish and recover the material of the sample from the floor material.
4.4.2.2 Shovels.
4.4.2.3 Rectangular sampling buckets, of sufficient size and of width not less than three times the nominal upper grading limit.
4.4.2.4 Suitable plates and wires, for sample reduction.
4.4.2.5 Containers for transport, such as bags, buckets or other suitable containers.
4.5 Sampling methods
4.5.1 General
Regulations for safety and ergonomics shall be followed.
WARNING Some sampling methods will inevitably involve the samplers working close to
processing plant and moving vehicles. Those involved in the planning and execution of sampling should work closely with the operational management to ensure safe working practices.
Mechanically selected gradings should preferably be sampled from a stationary conveyor belt or from the stream of material. Sampling increments should be taken at regular intervals throughout the period the batch is in motion. Gradings of which the pieces of armourstone are individually handled may be sampled at the most convenient location.
Sampling from static batches should be avoided wherever possible since it is difficult to satisfy the principle of taking sampling increments at random from all parts of the batch, and hence segregation is likely to cause the sampling to produce biased results.
During sampling, grabs or other extraction equipment shall be filled to a minimum such that the degree of filling does not adversely affect the representative nature of the sample or sampling increment.
4.5.2 Sampling, for the determination ofparticle size distribution, mass distribution and shape characteristics
4.5.2.1 Sampling ofmaterial in bucket conveyors, bucket loaders, or grabs
Each sampling increment shall consist ofthe entire contents ofa grab or bucket.
When this gives too large a sampling increment, it should be reduced by one of the methods described in 4.6.
4.5.2.2 Sampling at belt and chute discharge points
The period during which the sampling is to be done shall be divided into a number of equal intervals, and a sampling increment shall be taken in the middle ofeach interval.
A sample increment shall be taken by catching the discharge stream in a loader bucket, making sure that the complete cross-section of the stream of material is intercepted. At the beginning and the ending of the sampling, the edge of the bucket shall pass the cross-section of the stream as fast as possible.
Where appropriate, sampling should only be started after a preliminary run to ensure that possible irregularities in the pass do not lead to unrepresentative samples.
Samples may also be taken at the discharge from a screen by the same method.
43.2.3 Sampling from stationary conveyor belts
Sampling should only be started after a preliminary run to ensure that possible irregularities in the pass do not lead to unrepresentative samples.
All sampling increments shall be taken at the same sampling point. In every sampling increment, all material between two cross-sections shall be taken. The distance between the cross-sections shall be determined by the required quantity of the sampling increment.
4.5.2.4 Sampling from a silo
Sampling at a silo outlet shall be carried out in accordance with 4.5.2.2.
During filling of a silo the material segregates and as a result the finer material tends to be found in the centre of the silo with the coarser material along the wall sides. Alternating loading and discharging of a silo leads to a complex segregation pattern in the silo and this segregation causes variations in the particle size distribution of the discharged material. The number of sampling increments should be related to this variation.
4.5.2.5 Sampling from stockpiles
When sampling from a segregated stockpile, from which material is being collected for transporting, a sampling increment shall be taken from the material which is being taken from the stockpile. For this purpose, the contents of one or more loader buckets, grabs, lorries or any other means of handling or transport shall be taken. The period during which the sampling is done shall be divided into a number of equal intervals and a sampling increment shall be taken in the middle of each interval.
If at the time of sampling no material of a segregated stockpile is undergoing routine removal, the removal of material shall be simulated so as not to distort the representativity of the sampling increment with the segregation effects associated with the initiation of stockpile extraction. The sampling increments shall be taken at random or at equal distances around the stockpile or part thereof to be sampled.
When sampling from a non-segregated stockpile, a sampling increment shall be taken as indicated for a segregated stockpile or by taking a quantity of material from a random location which is easily reached with the equipment available.
4.5.2.6 Sampling from floating equipment
When sampling cannot be performed during loading or unloading, sampling from floating equipment should be performed with reference to Scheme 1 or Scheme 2 of Annex H.BS EN 13383-2 pdf download.
