Hello,

I want to simulate the thermal evolution of mass concrete in the ATENA transport module.
I have already watched two webinars (8/2022; 2/2023) on youtube related to the project.

As suggested in the webinars, I use the Moisture Temperature Boundary for Surface as a boundary condition for the external surface of the concrete block. Part of my project is to investigate the temperature distribution in concrete during hydration at different air temperatures. So in this boundary condition, I defined the air temperature as Ambient Temperature (e.g. 5°C), like in the webinar.

My problem is that this boundary condition behaves as if I am fixing the temperature on the surface. As opposed to gradually overheating the surface and beginning to release heat to the air.
This is a problem because the fixed surface temperature (e.g. 5°C) "pulls" the heat out of the concrete, so it cools much faster, especially at the edges.

The monitor point data on the surface also shows that the temperature does not change during the simulation (In contrast, the webinar 8/2022 shows that the temperature changes on the surface of the concrete element during the simulation in the presented project.)

What should I set so that the surface temperature is not fixed?
Maybe I should use different boundary conditions?
Has anyone else encountered this problem with this type of boundary condition?

Thanks for your help.