Polymer waterproofing of internal surfaces of headrace conduits at the Dneprogés-II hydroelectric plant

Conclusions

• 1. Construction and operation experience showed the effectiveness of and good prospects for the use of epoxycoal tar coatings for waterproofing pressure conduits.

• 2. The effectiveness, operating capacity, and durability of epoxy-coal tar waterproofings depend not only on the correct and well-grounded selection of the type of waterproofing, but also on the observance of all requirements contemplated in the techniques for carrying out waterproofing work.

• 3. High quality epoxy-coal tar coatings can be guaranteed on carefully prepared concrete surfaces; this should be taken into account in the design of waterproofings and in the preparation of projects for organizing and carrying out construction-erection work.

• 4. Since the application of waterproofings on intermal surfaces of conduits, which have, as a rule, pronounced slopes, and call for considerable additional expenditure in the erection and dismantling of scaffolds, in those cases in which it is possible to ensure crack resistance of the conduits by using additional reinforcement or increasing the area of the concrete sections, the use of waterproofings should be justified by economic analyses.