Physical testing of materials and coatings

Measuring the effectiveness of the waterproofing silicate materials

Hydrophobizations agents are used to limit penetration of aqueous solutions and vapor into the coat on the basis of silicates (facades, floors, concrete, concrete and fired roofing, masonry, etc.). Lifetime hydrophobization normally ranging 5 to 10 years according to the type used hydrophobizations agent. To measure the effectiveness hydrophobization used Karstensova tubes and similar methods, e.g. measuring the absorption of water 200 mm water column after 30 minutes into the matter to a defined surface wetting (50 cm2).

In SVÚOM s.r.o. was developed a test device for determining the quality of impregnation of hydrophobic silicate materials. The device is suitable for measurements in the laboratory (indoor) or outdoor and it can be ascertained not only the quality of the hydrophobic impregnation, but also the quality of seal coatings on silicate sealing documents. The principle of determination is the measurement of electrical parameters changes over time, which are a function of frequency and size of defects in hydrophobiced respectively sealing protective layer.

SVÚOM device has many advantages:

  • just place the test probe to the substrate
  • determination is carried out simultaneously with 4 probes (greater test area, shorter preparation time)
  • measured values are read from the digital display
  • there is no initial error due to time lag between the pouring of water into the tube and adjusting the height level
  • eliminating the so-called bubble error
  • eliminating the read errors of fall level caused due to adsorption of water into the cement bonding, due to evaporation of water from the tube or sticked and leaking down drops of water from the tube walls during filling
  • test method is not sensitive to temperature in the range 10 - 30°C
  • speed measurements: for quality resolution is good enough 90 minutes
  • high sensitivity and resolution

High degree of reproducibility of determination is also made 6-speed control:

  • automatic control and a visual indication of battery status
  • control of electronic circuits devices - performed before each measurement, it can be made at any time even during the measurement without influence on the measurement
  • control zero point without connected and connected and activated test probes using by first calibration standard
  • control activated test probes using by second calibration standard before each measurement and after 90 minute measurement

The chart is a comparison measure the effectiveness of hydrophobization concrete by gravimetric and electrometry method, with indicating the achievement of poor quality hydrophobic impregnation of concrete: electrometry observed marginal limit is 300 mV and measuring time 90 minutes.

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