BS/EN 1766-2017 pdf download.Products and systems for the protection and repair of concrete structures Test methods Reference concretes for testing.
Admixtures according to EN 934-2 shall be used.
5.5 Grit for surface preparation by blasting
Commercial grit for grit-blasting of concrete shall be used0 with grain size within the range of 0,25 mm to 1.0 mm, The grit shall not contain ferrous components such as chilled cast iron slag, which are prone to rusting.
5.6 SIlica sand for measuring roughness
Silica sand with a grain size of 0,05 mm to 0,1 mm, dried to a constant weight, shall be used.
6 Reference concrete mixes
6.1 General
This standard specifies eight types of reference concrete, defined by the maximum size of the aggregate and mix proportions. The reference concrete is chosen according to the type of product or system for the protection and repair of concrete structures and to the related test methods standards.
NOTE I The water taken into account hereafter in the water/cement ratio is the added water plus the water already contained in the admixtures and the additions.
Workability should be appropriate to achieve adequate placing of concrete with freedom from bleeding or segregation. Any special requirements for surface finish of placed specimens for particular test methods using reference concrete samples will be stated In those test methods.
Ad mixtures conforming to EN 934-2 are permitted to give a workable concrete mix to meet the requirements of Table 1 or to confer adequate freeze—thaw resistance by entrainment of air.
NOTE 2 The application of a suitable plasticizer or super plasticizer conforming to EN 934—2 is likely to be required to achieve optimum compaction, as described in 6.4.
6.2 Reference concrete with 16 mm or 20 mm aggregate
6.2.1 Compositions and properties (see Table 1)
6.2.1.1 Type C (0,40)
The mix shall contain 410/425 kg/rn3 cement and have a water/cement ratio of 0,40. Mixes shall have a
28 day mean compressive strength measured according to EN 12390-3 of (60 ± 5) N/mm2 for cubes and
(50 ± 5) N/mm2 for cylinders, a median tensile bond strength by pull off according to EN 1542 greater
than 3 N/mm2.
6.2.1.2 Type C (0,45)
The mix shall contain 360/375 kg/rn3 cement and have a water/cement ratio of 0,45. Mixes shall have a
28 day mean compressive strength measured according to EN 12390-3 of (50 ± 5) N/mm2 for cubes and
(40 ± 5) N/mm2 for cylinders and, when applicable, a median tensile bond strength by pull off according
to EN 1542 greater than 2,5 N/mm2.
6.2.1.3 Type C (0,70)
The mix shall contain 260/275 kg/rn3 cement and a water/cement ratio of 0.70 ± 0,05. Mixes shall have a 28 day mean compressive strength measured according to EN 12390-3 of (30 ± 5) N/mm2 for cubes and (25 ± 5) N/mm2 for cylinders and, when applicable, a mean bond strength by pull off according to EN 1542 greater than 1,5 N/mm2.
6.3 Reference concrete with 8 mm or 10 mm aggregate
6.3.1 Compositions and properties (see Table 1)
6.3.1.1 Type MC (0,40)
The mix shall contain 455/470 kg/rn’ cement and have a water/cement ratio of 0,40.
After 28 days the reference concrete shall have an average tensile bond strength determined by pull off according to EN 1542 wIth a minimum value of 3,0 N/mm2, but not for any individual result. The pull off test shall be carried out on the prepared concrete surface immediately before applying the material to be tested, using at least one substrate specimen from each batch of concrete. At least one in every 15 specimens shall be tested.
NOTE The requirements are usually met by a concrete with a compressive strength which satisfies class C50/60. as specified in EN 206.
6.3.1.2 Type MC (0,45)
The mix shall contain 395/410 kg/rn’ cement and have a water/cement ration of 0,45.
After 28 days the reference concrete shall have a median tensile bond strength determined by pull off, according to EN 1542 greater than 2.5 N/mm2, but not for any individual result. The pull off test shall be carried out on the prepared concrete surface immediately before applying the material to be tested, using at least one substrate specimen from each batch of concrete. At least one in every 15 specimens shall be tested.
NOTE The requirements are usually met by a concrete with a compressive strength which satisfies class
C 40/50, as specified In EN 206.
6.3.1.3 Type MC (0,70).BS/EN 1766-2017 pdf download.
BS/EN 1766-2017 pdf download
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