It is a clinker silo at the Lafarge Group “Aget-Heracles” plant in Volos. The silo is made of post-tensioned concrete. It is the largest of its kind in the Balkan countries with a capacity of 60,000 tons of clinker. Its diameter is 38 meters, its total height 45 meters and its cylindrical shell is only 40 cm thick and it is “post-tensioned”.

It has four tendon anchor points at its perimeter.

A composite frusto-conical shell of steel profiles and reinforced concrete, constitutes the roof of the silo and was constructed by the “free-cantilever” construction method. In this way the scaffolding up to such a high height was avoided. The foundations of the silo were constructed of variable length piles due to the slope of the rocky subsoil.

The construction of the cylindrical shell was carried out by the “slipping” formwork method. The construction took just four months and then the conveyor lines were erected to connect the silo to the plant. Particular attention was paid to the quality of the concrete and the “post-tensioning” to reduce the cracking within allowable limits.

Cracking could be caused due to the large temperature differences between the clinker inside the silo and the external environment.