Determination of water absorption and bulk density of all ceramic tiles
- Oven – capable of maintaining temp of about 1100c
- Balance – accurate to 0.01% of the mass of test specimen
- Water bath
- Chamois leather
- Wire basket
Preparation of Test Sample
- A test sample consists of 10 numbers of whole tiles. If the surface area of individual tile specimen is greater than 0.04m2, then the numbers of tile specimens in a sample can be reduced to 5.
- When the mass of each individual tile is below 50 g, then take sufficient number of tiles, so that each test specimen weighs 50g to 100g.
- If the dimension of tile is longer than 200 mm, then it may be cut up, but include the cut pieces in the measurement.
- Dry the tiles in the oven at 110±50C, until it attains constant mass, i.e. when the difference between two successive weighing at intervals of 24 h is less than 0.1%.
- Cool the tiles in the desiccators over silica gel, until cooled to room temperature.
- Weigh each tile specimen and record the weight of individual test specimen (i.e. m1) in the observation sheet.
- Place the tiles vertically, with no contact between them, in water in the water bath so that there is a depth of 50 mm water above and below the tiles. Maintain the water level 50 mm above the tiles throughout the test.
- Heat the water until boiling and continue to boil for 2 h. After 2 h, switch off the source of heat and allow the tiles to cool, still completely immersed in this water, over night.
- Remove the tiles from the water bath and remove the surface water from the tiles pieces by chamois leather.
- Immediately weigh each tile and record the weight (i.e. m2) in the observation sheet.
- Now place the specimens in the wire basket that is immersed in water and determine the weight of each specimen to the nearest 0.01g.
1. Water Absorption
For each tile, calculate the water absorption in percentage (to the first decimal place) of the dry mass using the following formula.
Water absorption (%) = [(m2 – m1) / m1] * 100
m1 = mass of the dry tile, in g
m2 = mass of the wet tile, in g
Calculate the average water absorption of the sample as the average of the individual result.
2. Bulk Density
Bulk density (B), in g/cm3, of a specimen is the ratio of its dry mass divided by the exterior volume, including pores. Calculate bulk density of tile as follow.
B = m1 / V
B = bulk density of tile, g/cm3
m1 = mass of dry tile, g
V = exterior volume, in cm3: = (m2 – m3)
m3 = mass of suspended tile impregnated by boiling water method, in g
Calculate the average bulk density of the sample as the average of the individual result.
The test report should contain the following.
- Description of the tiles
- Water absorption & bulk density of each tile specimen
- water absorption and bulk density
IS: 13630 (Part-2) – ceramic tiles – methods of tests, sampling and basis for acceptance [Part 2 – determination of water absorption & bulk density]