Coatings and paints

[Rodopoulos]

Dear Forum

is there a way to simulate the water transmission resistance of a coatings or paint on a concrete surface or plaster?

[Christian Bludau]

Dear Rodopoulos,

have a look on our "Guideline for modeling water-repellent treatment of a façade" in our download section:
https://wufi.de/en/service/downloads/#w ... _treatment
By adapting the thickness, the a-value and the µ-value, you can also use that for coatings.

Best regards,
Christian

[Rodopoulos]

Dear Christian

many thanks. It makes sense. I presume that the same stands in the case of modelling a concrete hydrophobic impregnation according to EN 1504-2? My only concern is the free water saturation value since the surface treatment takes place after 40-50 days of pouring concrete. The way I see it is to run the model without the extra impregnated layer at the beginning, save the results using the monitor points (thickness) of the bulk concrete and then add a new layer as described in the "Modelling water-repellent treatment of a façade by adjusting the A-value". The question that emerges is whether Wufi 2D can save the moisture profile along concrete thickness and use it as a input for the new model?

Cheers

Chris

[Christian Bludau]

Hi Chris,

yes thats possible.
Build up your construction, split off the layer for the coating. Assign the same material for wall and coating.
Then calculate the first 40-50 days.
In WUFI Motion go to the wanted time step (eg. after 50 days) and export the profiles for T and RH by doing a right click on the 3d-view of T and RH and select export -> initial conditions as two separate files.
Now change the material properties of your coating in a copy of your first calculation and select the two files as initial conditions.
Please take care, that the start date of the second calculation is the same as the date from the initial profile.

Christian