4 SUMMARY
This thesis is an invention project regarding the thermal conductivity of concrete.
Thermal conductivity (λ-value) is a material constant that describes how well a substance is as a heat conductor. Concrete λ-value is 0.8 wm-1k-1.
Concrete is one of our main building materials, an improvement of the thermal conductivity of concrete may result in great advantages in terms of energy saving, therefore, we tried to mix concrete with other materials (batch) to raise the concretes λ-value.
We replaced part of the sand or removable filler with batch. The compensation volume ranged from 50%, 60% or 70% in the different mixtures we tested. In some cases we got blisters, which weakened the concrete. In all cases where blisters occurred, we used Portland cement.
Plates, where we used an levelling mass for flooring or aluminate cement made it better.
The following results of my tests show some of the changes in the λ-value we received during the project.
λ-value (wm-1k-1) Batch in % Cement
0,7064 0 Portland cement
2,9788 50 Levelling mass
2,4978 50 Aluminat cement
Improvement of the thermal conductivity of concrete can be extremely useful in floor heating systems and heating of pavements.
