BS EN 771-5-2003 pdf download.Specification for masonry units Part 5 : Manufactured stone masonry units.
When manufactured stone masonry units are intended to be used with thin layer mortar, the manufacturer shall declare the maximum deviation from flatness of the bed faces.
If sampled in accordance with Clause A.2 and tested in accordance with EN 772-20, the deviation from flatness of the bed faces shall not exceed the declared value.
5.2.2.3 ParallelIsm of bed faces
When manufactured stone masonry units are intended to be used with thin layer mortar, the manufacturer shall also declare the maximum deviation from plane parallelism of the bed faces.
If sampled in accordance with Clause A.2 and tested in accordance with EN 772-16 Method d), the deviation from plane parallelism shall not exceed the declared value. iI
5.3 E Configuration and appearance J
5.3.1 General
Units may be homogenous or two-part but in the case of two-part masonry units the facing mix shall have a thickness of not less than 20 mm. There shall be no delamination between the facing and the backing concretes. Ii Text deleted 1
5.3.2 jj Configuration
When relevant to the uses for which manufactured stone masonry units are put on the market, the configuration shall be declared, including the maximum area of voids on a bed face as a percentage of the length x width of the unit. The declaration may be made using a drawing or an illustration.
Units intended for use in structural applications shall contain not more than 60 % by volume of all formed voids and may be provided with or without recesses or interlocking features. Such units containing not more than 25 % by volume of formed voids and having no single void greater than 12,5 % of the total volume of the unit may be declared as Group 1 masonry units, in accordance with the requirements of EN 1996-1.1.
When conformity with the declared configuration cannot be assessed by visual inspection, masonry units shall be sampled in accordance with Clause A,2, measured in accordance with EN 772-16 and the values calculated. (J
5.3.3 I1) Surface appearance (I
The exposed surfaces of manufactured stone masonry units shall be I!i) plane €1. profiled or textured as declared by the manufacturer. Compliance of textured or profiled surfaces may be established on the basis of comparison with any approved samples. Comparison shall be made from a distance of 3 m in normal daylight conditions.
5.5.1 Declared value
The normalised strength of the manufactured stone masonry units in compression shall be declared by the manufacturer (declared value-for definition see 3.15). Either the mean or the characteristic (5 % fractile) value may be declared but it shall be clearly stated which has been declared. The declaration shall relate to and indicate the intended orientation(s) of the masonry units as tested, the method(s) of bedding the units and whether any voids present are intended to be fully filled with mortar. In addition the manufacturer shall declare whether the manufactured stone masonry unit is classified as Category I or Category II (see ZA.2).
If surface preparation is required (see 7.2.1 of EN 772-1:2000) it shall be carried out in accordance with 7.2.4 or 7.2.5 of EN 772-1:2000 and the units shall be conditioned in accordance with 7.3.2 a) or 7.3.5 of EN 772-1:2000. The manufacturer shall declare the conditioning regime and the surface preparation to be used in establishing compliance with the declared compressive strength of the units.
The procedure for norrnalising the compressive strength of a unit is given in annex B.
The compressive strengtn snail be determined by testing either whole masonry units or cubes of dimension 100 mm or 150 mm. Cubes may be cut from a unit or may be prepared from samples of the unformed mix moulded in a manner to obtain a level of compaction similar to that attained in the unit.
If sampled in accordance with A.2 and tested In accordance with EN 772-1 using the surface preparation and conditioning as given above then:
Conformity with the declared Mean Value of the normalised compressive strength shall be met if the mean of the normalised compressive strengths of the six units tested is not less than the manufacturer’s declared value and no individual norrnalised compressive strength is less than 0,8 x the declared value:BS EN 771-5-2003 pdf download.