A containment structure for containing therein carbonaceous bodies and for introducing the containment structure with the carbonaceous bodies therein into a furnace for the calcination of the carbonaceous bodies, the containment structure comprising, base supports horizontally spaced at regular distances from each other, a rest grid defining horizontal bottom beams with opposite end portions, said base supports having central seat formations and lateral stepped groove formations for receiving therein said opposite end portions of said beams, horizontal loading plates supported on said grid, pillars supported in said central seats and extending upwards therefrom, said pillars having longitudinal flutes, the flutes of opposite pillars facing each other, wall defining plates having edge portions seated in said flutes, said wall defining plates including side wall defining plates, said pillars including side wall plates supporting pillars arranged in outwardly yieldable relationship with respect to said bottom plate means.