The method is based on measuring mass increase due to capillary absorption of water in a predetermined time interval. The mass of water is expressed as a coefficient that indicates the tendency of the sample to absorb water by capillary, without application of an external pressure. The test is carried out on three cylindrical samples of 100 mm diameter and 25 mm thick cured under standard conditions (20°C, RH 95%) for 28 days. Before the test, weigh and record the sample sizes. Draw eight equally spaced axial lines along the perimeter of the test face for the entire height of each sample. Place the face of the sample test on the supports of a tray with a flat bottom with an amount of water sufficient to obtain a depth immersion of (2 ± 1) mm for each sample. Apply the cover on the tray to prevent the evaporation of air around the test sample. Determine the water absorption of the sample at test intervals commensurate with the rate of sample absorption taking at least six readings of values. The reading of the results must always be performed every 2 hours. The appropriate reading intervals are 12 minutes, 30 minutes, 1 hour, 2 hours, 4 hours, and 24 hours. The reading of values ​​must always be carried out after 2 hours. Remove the sample from the tray, and then dry with paper to remove excess water. Determine the mass of the sample, using the balance. Record the position of the wet part after 2 hours and immediately re-enter the sample into the tray, and then replace the cover above. The water absorption per unit area (s) must be calculated for each time increment as the ratio between the mass of water absorbed (kg) and the surface of the face under test (m2). Using a graph, you can determine the curve as a function of the square root of the immersion time (h). It therefore determines the slope of the resultant line, which should appear linear. The slope of the curve is defined as the S absorption coefficient [kg / (m2 * h 0.5)]. This test procedure is used to test self-leveling, repair mortars, grouts gypsum, surface repair mortars.


Material type Standard Test method
screeds EN 13813 EN 1062-3
self-levelings EN 13813 EN 1062-3
restoring EN 1504-3 EN 13057
surface protection mortars EN 1504-2 EN 1062-3


The method is based on measuring of increase bulk due to capillary absorption of water in a predetermined time interval.


Instruments used to perform the test: Scale, Ventilated oven