The test method for measuring the effect of the dry thermal cycles without exposure to de-icing salts. It is required for each test three of concrete substrates of dimensions 300 mm x 300 mm x 100 mm, one of which serves as a reference sample. Before applying the repair product or surface protection system, all systems must be kept in a climate of standardized laboratory for at least 24 hours. Products must be prepared and applied to concrete samples according to manufacturer's instructions. After applying the samples, cure them for 28 days under standard conditions (20°C, 95% RH). After you complete preparation, two samples must be tested. Start test cycle of 6 hours which comprises the following steps:

  • Cooling from (21 ± 2)°C to (-25 ± 2)°C at a spped of 3°C/min (15 min);
  • 153 minutes of air storage at T = (-25 ± 2)°C;
  • 27 minutes of air heating at T = (55 ± 2)°C (speed: 3 ° C/min);
  • 153 minutes of air storage at T = (55 ± 2)°C;
  • 12 minutes of air cooling at T = (21 ± 2)°C (speed: 3°C/min).

The third reference sample must be stored in a standardized laboratory climate. The test cycle must be repeated depending on the performance requirements of the product tested. After completing the cycle, on the two samples will be carried out five adhesion tests. Five test areas of cross section of about 50 mm must be subjected to coring. The test areas must be at least 50 mm away from each other and at least 50 mm away from the edge of the sample. The cut must penetrate for the entire screed and for more than 5 mm deep in the substrate. Then apply the steel plates with an adhesive on the five carotate areas. Finally, place the device to measure the adhesion strength. Apply force through the device and the display will show the breaking load (kN) at the time of the break. By means of a visual evaluation the type of breaking sample can be determined. The types of breaking are:

X = cohesion breaking in the concrete substrate;

X / Y = breaking between the substrate and the screed;

Y = cohesion breaking in the screed;

Z = breaking between the adhesion layer and the plate with the pulling head.

 

Material typeStandardTest method
finishing plasters EN 998-1
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gypsum-based plasters EN 13279-1
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self-levelings EN 13813
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restoring mortars EN 1504-3 EN 13687-4
waterproofing EN 14891
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surface protection mortars EN 1504-2
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Instruments used to perform the test: Climatic cabinet for curing, Pull-off

 

The test method for measuring the effect of dry thermal cycling without de-icing salt exposure.The test method for measuring the effect of dry thermal cycling without de-icing salt exposure.The test method for measuring the effect of dry thermal cycling without de-icing salt exposure.