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Notes: 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.

Notes: Conclusions 1. To eliminate the joint between the upstream zone of ordinary concrete and internal zone of rollcrete, a design of a gravity dam is proposed with the construction of a sawtooth joint between these zones, which is obtained by tiered placement at first of 2–4 layers of rollcrete and then concrete of the upstream zone with the use of the layerwise method. The joint of the two types of concrete is carried out through the inclined area of undercompacted lean concrete, which is formed naturally along the slope of 2–4 layers of lean concrete mix having an average gradient of 1∶0.1 toward the upstream pool. On the next tier up the joint of the two concretes is shifted toward the upstream face, which creates localness of the undercompacted areas of concrete and, on the whole, the sawtooth shape of the contact of the upstream and internal zones of the dam. 2. On the downstream face it is suggested to protect the rollcrete with an insulating layer made of triangular precast reinforced-concrete elements, inside which is located insulation. The tiered installation of the precast elements with rolling of 2–4 layers of lean concrete on them creates the sawtooth joint between the internal and downstream zone of the dam, providing minimum effects of the outside air temperature fluctuations on the load-bearing profile of the structure. 3. The proposed design of the dam allows uniform tiered placement of the concrete, and two methods of concreting: rolling of the lean concrete and vibration by the suspended packet vibrators can be separated within the tier so as to maximally simplify the technology of constructing the dam. The layerwise method of concreting the upstream zone of the dam and the method of rolling the lean concrete in the internal zone coincide in many technological operations, which on the whole enables their successful combination when constructing the dam and creates favorable conditions for providing solidity of the structure. 4. In further investigations it is necessary to calculate the stress state of the dam with variation of the location of the contact between the zones of concrete of different type in plan and over the height. In a particular development of the design of a dam with a downstream insulation zone, investigations of the effect of the thickness of the insulation zone on the calculated profile of the dam, accompanied by the selection of the type and thickness of the insulation material in relation to the climatic conditions of the construction region, will also be required.

Notes: Summary 1. Seven years of laboratory testing and practical experience have demonstrated the possibility and desirability of using reinforced epoxy-coal tar waterproofing for protecting hydro-engineering structures. 2. The compounds developed have properties generally superior to those of ordinary epoxy waterproofing while the water resistance, low-temperature resistance, and resistance to temperature drops are considerably better. 3. A technical and economic analysis has established that reinforced epoxy-coal tar waterproofing is the most economical for use in the presence of constant shear and compressive loads.

Notes: Conclusions 1. Laboratory and full-scale investigations showed the possibility of using coatings of epoxy-coal tar foamed plastic for insulation-waterproofing of hydraulic structures in regions with a rigorous climate. 2. It was established that in the case of the same insulating effect the insulation-waterproofing of epoxycoal tar foamed plastics is one of the most economical in the construction of structures by any method. 3. For zones of a variable water level, on structures not subjected to the effect of ice, insulation-water-proofing with a protective enclosure of glass-reinforced plastic can be recommended. Under constant ice conditions it is necessary to use coatings with a sheet-metal enclosure. 4. In connection with the increased shrinkage of the epoxy-coal tar foamed plastics the thickness of coatings on their base should not exceed 5cm. It is necessary to continue the search for cheap foamed epoxies not having a high shrinkage.

Notes: Abstract An investigation is made of the microwave surface resistance R s measured at 10 GHz and 77 K, as a function of the thickness of superconducting epitaxial films of yttrium barium cuprate grown on lanthanum aluminate substrates by magnetron sputtering. Films between 200 and 1800 nm thick have low values R s (0.3–0.5) mΩ and do not show any deterioration. The level of R s achieved in films of comparatively large thickness is mainly attributable to the low rate of film growth (0.8 nm/min).

Notes: Abstract The effect of the ratios of the cationic components and internal strains on the critical temperature T c and the dielectric characteristics of BSTO ferroelectric films grown on α-Al2O3 [1012] and LaAlO3 substrates were investigated. Ion backscattering diagnostics revealed a barium deficiency in the surface layer of the films and showed that the films differ in structural quality.

Notes: Conclusions 1. Laboratory investigations and experience in the application and operation of epoxy-coal tar waterproofing showed that it can be used in the construction of hydraulic structures instead of steel under conditions of the combined effect of earth pressure to 600 tons/m2, hydrostatic head to 300 m, and constant shearing forces to 100 tons/m2. 2. The use of epoxy-coal tar waterproofing instead of steel effects a considerable saving due to a decrease in labor costs, elimination of the consumption of scarce low-carbon and stainless steels, and reduction of the time of construction and assembly work.

Notes: Conclusions 1. Experience with the use and operation of epoxy-coal tar waterproofing showed that it can be used in hydraulic engineering under the following external effects: hydrostatic head to 270 m, brief counterpressure to 0.4 MPa, constant vertical pressure up to 6 MPa, constant shearing forces to 1 MPa, stream velocities to 6 m/sec, opening of cracks in the waterproofed elements with a width to 1.5 mm, and periodic effect of individual blocks of ice and floating objects. 2. It was established that the use of epoxy-coal tar waterproofing is most effective for providing impermeability of noncrack-resistant thin-walled water-conducting structures (penstocks, pipelines, spiral casings, wasteways, etc.) and elements subjected to the effect of constant shearing and compressive loads (foundations of pumping stations, cores of dams, and grouting and inspection galleries).

Notes: Conclusions 1. Investigations, design, and operation showed the technical and economic expediency of using epoxy-bitumen coatings as waterproofing of hydraulic structures related to the passage, storage, and treatment of potable water. 2. The most effective area of use of epoxy-bitumen coatings is for waterproofing thin-walled non-crack-resistant components and structures.