The Kozienice Plant: DYWIDAG Strand Post-Tensioning Systems for Poland’s second largest Coal-Fired Power Plant
With a total generating capacity of approximately 2,900MW, the Kozienice Power Plant southeast of Warsaw is Poland’s second largest coal-fired power plant and consists of 10 generators. In 2014, construction of an 11th generator started that will provide an additional 1,075MW of energy after its completion in mid-2017.
A part of this huge construction project is a retention facility for fly ash produced in the coal burning process. The fly ash is stored in 3 identical tanks, each of them providing 20,000m3 of storage capacity. These slender concrete structures have inner diameters of 25.8m, 48.3m high chambers and a wall thickness of only 300mm.
The tank walls were post-tensioned using 7 strand “hoop” tendons that were installed in the perimeter and anchored in pilasters. Each “hoop” consists of 2 half-circle tendons.
DSI Construction Poland was awarded the post-tensioning work. The scope included the technical support of the subcontractor during post-tensioning and the supply of approximately 8,400m of Type 6-7 SUSPA Systems Strand Tendons with 1,152 MA Stressing Anchorages. The 576 bonded tendons in accordance with ETA-06/0025 consist of Type 0.62", Y1860S7 strand. Furthermore, DSI installed, stressed and grouted the strand tendons and provided different documentation in addition to the stressing records.
In addition to the tight schedule, the very large height of the 65m tall tanks represented a challenge: The highest tendons were installed at a height of 62.25m above ground.
Furthermore, due to the fact that the chamber walls were erected using sliding formwork technology, and due to the small amount of storage space, all of the post-tensioning systems had to be supplied to the jobsite just-in-time.
Thanks to the minimal space requirements of the strand tendons that were supplied by DSI on coils, the pilasters were realized very efficiently. Also, the robust post-tensioning system provided by DSI ensured an easy installation of the MA Anchorages and trumpets. The accessories supplied by DSI – especially the reliable threaded connections between the PE grout caps and the anchor plates – ensured that grouting work proceeded smoothly.