EN 1367-7-2014 pdf download.Tests for thermal and weathering properties of aggregates – Part
7: Determination of resistance to freezing and thawing of Lightweight aggregates.
5.1 AU apparatus, unless otherwise stated, shall conform to the general requirements of EN 932-5,
5.2 Ventilated drying oven, with forced circulation of adequate capacity. The oven shall be capable of being maintained at (110± 5) C.
5.3 Balance, capable of weighing test specimens up to 400 g with an accuracy of ± 0,04 g and test specimens above 400 g with an accuracy of 0,1 g.
5.4 Low temperature cabinet, (upright or chest) with air circulation, The cabinet shall be capable of being maintained at (—17,5 ± 2,5) C.
5.5 Test sieves, conforming to EN 933-2 shall be used.
5.6 Water, distilled or deionised.
5.7 Container, made from corrosion resistant matenat with a base area of approximate 0,02 m2 and a height not less than 0,1 m.
5.8 Grid, of a suitable size and aperture to prevent the lightweight aggregates floating out of the container and to prevent any loss of whole aggregates.
5.9 Water bath, thermostatically controlled to maantain a temperature of (20 ± 3) C.
6 Sampling
Sampling and sample reduction shall be camed out in accordance with EN 932-1 and EN 932.2.
7 Test specimens
7.1 General
Three individual test specimens shall be used. The test specimens shall be obtained in accordance with
EN 932-2 by sample reduction. Particles of oversize (>0) and undersize (<ci) shall be removed,
7.2 Size of test specimens
The quantities for each of the three individual test specimens shall be chosen according to the upper size of the aggregates as shown in Table 1. Deviations of ± 5 % in the volume of test specimens are permissible.
Weighing shall be carried out to the following accuracies:
• Test specimens up to 400 g: to ± 0,04 g.
• Test specimens above 400 g: to ± 0,1 g.
8 Procedure
8.1 Soaking
Store the test specimens at atmospheric pressure for (240 ± 15) mm in the containers specified in 5.7 at
(20 ± 3) ‘C in distilled or deionised water, ensuring that the water covers the test specimens by at least
10 mm. In order to prevent the test specimens floating, the specimens are kept submerged by a grid as
specified in 5.8.
8.2 Freezing in air and thawing In water
Remove the test specimens from the containers and allow them to drain on a sieve with a maximum size of 2 mm for about 1 mm. Then place them back into the containers spreading them out evenly.
Place the containers in the low temperature cabinet, ensuring that the heat is extracted as uniformly as possible from all sides of all test specimens. The distance between each container, and between the containers and the sidewalls of the cabinet, shall not be less than 50 mm After placing the containers In the cabinet, hold the air temperature In the cabinet at (—17.5 ± 2,5) ‘C.
The containers with the test specimens shall remain In the cabinet for minimum of 240 mm.
After completion of the freezing cycle, remove the containers from the cabinet, add water to the containers with the test specimens and store for at least 60 mm in a water bath at a temperature of (20 ± 3) ‘C. In order to prevent the test specimens floating, the specimens are kept submerged by a grid as specified in 5.8.
Pour off the water from the containers carefully and allow the test specimens to drain for about I mm. Then start the next freezing cycle. In total 20 freeze—thaw cycles shall be performed.
If it is necessary to interrupt the test, the test specimens should remain in the cabinet at (—17,5 ± 2.5) ‘C.
On completion of the 20th freezing and thawing cycle, pour the contents of each container into a sieve having an aperture size that is half the lower size sieve used to prepare the test specimen (e.g. in case of the 8 mm to 16 mm fraction, pour into a test sieve of 4 mm aperture size). Wash and sieve the test specimen on the specified sieve by hand. Dry the residue remaining on the sieve at (110 ± 5) ‘C to constant mass, cool at ambient temperature and weigh immediately (P4 see Clause 9).EN 1367-7-2014 pdf download.