The air-entraining agent used was Micro Air FC, that is a reddish liquid, free
from chlorides, used in concrete and mortar. The air-entraining agent introducing microbubbles of air which prevents the penetration of deep water, homogeneously distributed, making the concrete less permeable and more resistant to the action of aggressive agents, and is compatible with all types of cement. The air-entraining agent used was supplied by Basf.