Experience with the construction of impervious membrane elements on the upstream cofferdam at the Toktogursk hydroelectric plant, a head-producing dam on the Kara Su River , the dam at the Atbashinsk hydroelectric plant (1969)(1970)(1971), and the cofferdam at the Ust'-Khantaisk hydroelectric plant (1970) [1-3] as well as with laboratory work carried out at the B. E. Vedeneev All-Union Scientific-Research Institute of HydrauUc Engineering (VNHG) has indicated the need for developing simple and technically adequate elements, for improving their reliability, for justifying the methods of analysis of such elements, and for determining the durability of the materials used for these elements.

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The increasing rate and volume of modern hydraulic construction, especially in the northern and eastern regions of the Soviet Union, require a radical improvement in the designs of hydraulic structures and methods of constructing them. The traditional materials do not always meet the increasedrequirements of modern construction and this raises new problems on the use of polymers, creating of structures on their base, and new methods of conducting hydraulic engineering operations.The chemical industry of the USSR is producing plastics on an ever-larger scale. According to the Five-Year Plan of development of the USSR national economy for [1971][1972][1973][1974][1975], the production of plastics is supposed to increase 'twofold, and of rubbers 1.7 times. However, only a small part of the total production of polymers is used for construction. Plastics are being introduced into hydraulic construction completely insufficiently. This is explained by the comparatively few investigations devoted to finding the possible areas of use of plastics and the inadequate coordination of studies in this field.Most often used in hydraulic construction are epoxy, polyester, phenol formaldehyde, and furfural resins and glass-fber-reinforced plastics on their base, polyethylene, synthetic rubbers, bitumen-polymer composites, etc.( Fig. 1).Anticavitation and anticorrosion protection of structures and hydromechanical equipment is accomplished by polymeric paint and mastic plaster coatings. These coatings are used for anticavitation protection of concrete on the spillway faces of dams, in the spiral cases and draft tubes of hydraulic turbines, and in bottom discharges and mnels. Investigations showed that epoxy mastics and polymer-mortars have a cavitation resistance greater by 2-3 orders than high-strength concrete. Composites based on epoxy resins modified by polyester MGF-9, nitrile and carboxylated rubbers SKN-10A, and SKN-18, thiokols, and other combined plasticizers have the best cavitation properties. Such coatings are placed on the spillway faces, tunnels, bottom outlets, and other structures of the Bratsk, Krasnoyarsk, Nurek, Charvak, and other stations. These coatings are 3-6 times cheaper than metal facings. A special standard has been developed at the B. E. Vedeneev All-Union Research Institute of Hydraulic Engineering 0TNIIG) and research department of the All-Union Planning, Surveying, and Research Institute (Gidroproekt) and is being prepared for publication. According to the investigations of UkrVNIIGiM, the facing of furfural and phenol formaldehyde polymerconcrete proved to be resistant to the abrasive wear by sediments. Such facings are operating successfully on the Sary-Kurgan dam under conditions in which steel facing is worn at a rate of 1.5-2 mmt~jrear.The epoxy paint coatings are, as practice shows, a reliable anticorrosion protection of underground and underwater steel structures. The paint ~FAZhS based on epoxy resin modified by monomer FA is used for protecting the cable lines of the 22rid Party Congress Volga...

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