ITD Cementation has taken the challenge of constructing this 48m diameter and 21 m high DWST with 1000mm wall thickness at bottom, decreasing gradually to 600mm up to 7m height. Considering the Doka’s engineering expertise in building circular tanks, ITD cementation was convinced to use Doka formwork system. Both inside and outside formwork solution was provided with a combination of Doka Wall Formwork Top 50 assembled along with Crane handled Climbing Formwork 150F with 3.5 m casting steps. This tank also has four concrete buttresses to provide support against the heavy pressure of Liquid Ethylene, for which special solution with Top 50 was evolved. To cast the ring beam at the top, additional sets of Special Cantilever Brackets were introduced so as to overcome the sudden increase in wall thickness.
Moreover, normally to make a circular panel, concrete facing ply is provided with a shaping timber support and then afterwards H20 beams and steel wailers are used, which results in a requirement of huge quantity of timber for packing. But Doka provided a unique solution i.e. concrete facing ply was supported by H20 Beam which in turn was connected to steel wailers by packing timber at wailer location only, connected through different lengths of cup square bolts. This solution saved the considerable amount of timber.