Tests on new types of vibrators at the Sayano-Shushenskoe hydropower scheme

Abstract

1. The tested new, experimental, prototypes of vibrator equipment with a vibrational speed of 3000 osc./min, viz., vibrators V-1-691 and horizontal vibrators of the “torpedo” type, enable the thickness of layer being worked through to be increased up to 1.2–1.5 m. It was found that, in order to work through the upper zone of the block, the vibrator should be extracted in steps, with a pause in the center of the layer. 2. The oscillations transmitted from vibrator V-1-691 to the concrete mix, with the vibrator in the vertical position, are insufficiently strong and, therefore, it can be used only for compacting mixes with a slump of not less than 3 cm. The time for working through a concrete layer 1.2 to 1.5 m thick should be increased 30% in comparison with the compaction of 50-cm layers. In the future, use of the somewhat more powerful (but close in regard to parameters) vibrators of the type V-1-697 is preferred. They have proved themselves during construction of the Dneprovsk hydropower plant II according to data obtained by NIS of Gidroproekt. 3. The operating efficiency of horizontal vibrators of the “torpedo” type is considerably higher than of vertical units; consequently, they can be recommended in long blocks for compacting concrete mixes with a slump of 2–3 cm and layer thickness of 1.2 m and, after supplementary verification, for layers 1.5 m thick. 4. With regard to the above results, it is essential to expedite the manufacture of trial batches of new compactors for their use in placing layers of greater thickness.