AS ISO 10545.3-2020 pdf download.Ceramic tiles Method 3: Determination of water absorption, apparent porosity, apparent relative density and bulk density.
7 Procedure
7.1 Sample preparation
Dry the test specimens to constant mass (see NOTE) in the oven (5.1) adjusted to a minimum of 110 °C,not to exceed 160 °C for a minimum of 24 h (or such other time as has been established for the oven in use and the mass of tiles being dried). The drying of the specimens and the determination of their masses may be done either before or after the specimens have been impregnated with water. Usually the dry mass is determined before impregnation. However, if the specimens are friable or evidence indicates that particles have broken loose during the impregnation, the specimens shall be dried and weighed after the suspended mass and the saturated mass have been determined. In this case, the second dry mass shall be used in all appropriate calculations.
NOTE Constant mass is reached when after two subsequent weightings, the final weight does not change more than 0.1 %. Specimens being tested directly following their manufacture can be considered fully dried so long as they have not been subjected to any process that wets the specimen post firing (such as can occur in cutting and polishing operations), and they are placed in a desiccator sufficiently quickly (usually within no more than 30 mm of exiting the kiln) that no moisture has been absorbed from ambient air, as can be confirmed by weighing to constant mass after impregnation.
Cool the tiles in the desiccator (SA) over silica gel or another suitable desiccant but not an acid.
Weigh each tile and determine with an accuracy of 0,01 % of the mass, the mass, ml, of each specimen.
7.2 Impregnation with water
Place the tiles vertically with one of the cut side facing the bottom, with no contact between the specimens and the chamber (5). Evacuate to a pressure of 10 ± 5 kPa (91 ± 5 kPa below standard atmospheric pressure of 101 kPa) and maintain it for 30 ± 2 mm. Then, while maintaining the vacuum, slowly admit sufficient water, taking no longer than 10 mm to cover the tiles by at least 5 cm. Release the vacuum and allow the tiles to remain submerged for 15 ± 2 mm. Determine the suspended mass according to Z3. After the determination of the suspended mass, or directly after the 15 ± 2 mm soak. if the suspended mass is not determined, blot each specimen lightly with a damp microfibre cloth to remove all visible water droplets from the surface, and determine the saturated mass m, of each specimen, with an accuracy of 0,01 % of the mass. A dry microfibre cloth shall be saturated with water equal to two times its dry weight (for example, a 50 g cloth is saturated with 100 g of water). This may be achieved by placing the cloth in a bowl, adding the required amount of water, and squeezing the cloth to ensure all of the water is absorbed and that the cloth is evenly saturated without any dry areas. The facial area of the microfibre cloth shall be at least 65 % of the total facial area of specimens tested (for example, five 20 x 20 cm specimens require a microfibre cloth surface area of 1 300 cm2 or greater). Multiple microlibre cloths may be used to meet the required minimum cloth facial area. The blotting process shall involve patting the specimen lightly on all edges and surfaces with the damp microfibre cloth. Take care not to blot excessively as this could introduce error by withdrawing water from the pores of the specimen. Weight determination shall be performed immediately after the blotting process to avoid errors due to evaporation of water from the test specimen.
Repeat as necessary until all required specimens have been tested.
7.3 Suspended weight
After impregnation under vacuum of the test specimens, determine, with an accuracy of 0,01 % of the mass, the mass, m3, of each specimen while suspended in water. Carry out weighing by placing the specimen in a wire loop, halter, or basket (&) that is suspended from one arm of the balance (52). Before actually weighing, counterbalance the scale with the wire ioop, halter, or basket in place and immerse in water to the same depth as is used when the specimens are in place.
8 Expression of results
8.1 Water absorption
In the following calculations, the assumption is made that 1 cm3 of water weighs 1 g, where
ml is the mass of the dry tile;
m2 is the mass of the tile impregnated by immersion under vacuum;
m is the mass of the suspended tile impregnated by immersion under vacuum.AS ISO 10545.3 pdf download.