WUFI

Hi,
I wanted to know if there were data on wufi concerning the critical water content beyond which the material can be damaged (mechanical properties degraded, crystallization of salt...). For example, I read on the Internet that there are criteria such as the fact that it is recommended not to exceed 4 to 5 kg/m^3 of water content for mineral wools or that the water content of concrete must remain below its water content at equilibrium with 85% relative humidity. Nonetheless I wanted to know there were more precise values of critical water content in Wufi or if you knew sources that gave this kind of information ?
Kind regards
Tobias

Hi Tobias,

yes, this is an important question because WUFI's results only describe temperatures, water contents etc in the construction, but the user is usually interested in an assessment about the performance or durability of the construction.

For this purpose, information about allowed limits with respect to various damage mechanisms is needed. Unfortunately, not much is known about these limits at present, this is an area of current research. For a discussion of possible damage mechanisms and existing knowledge about admissible limits, please see the topic

• "Appendix | Assessment Criteria"

in WUFI's help file, or (with identical content) the topic

• Analysis, interpretation and assessment of the calculation results

here in the WUFI forum.

Kind regards,
Thomas

Hi Thomas,
Thank you for your answer!
Kind regards
Tobias

Hello,
In addition, i understand that i assess my non- frost resistance materials (such as brick, plasters) in the context of frost damage risk. For this,i do that in my wall section i assess my brick layer frost risk by values of WUFI excel sheet with the suggestions of guideline (WUFI). And these criterias are ; T<0, RH>95 and %30 wmax. According to these criterias I will assess all the hours values by Excell outputs and find the amount of freeze cycles...Is it a right assessment ?
Thank you.
Best regards.
Pelin.