Vízügyi Közlemények, 1989 (71. évfolyam)

1. füzet - Bognár Győző-Hajós Béla-Kiss Jenő-Stimm Miklós-Szepessy József: Műszaki fejlesztés a vízépítés területén

54 Bognár G y., Hajós В., Kiss J., Stimm M. és Szepessy J. чтобы используемые химические средства не наносили вред окружающей среде. Необходимо прикладывать усилия для разработки отечественних видов химических средств, используемых для ремонта сооружений бетоном с химическими добавками. В интересах решения наиболее важных проблем авторами приводятся различные предложения для выноса соответствующих решений. Technical development in water engineering by Dr. G. BOGNÁR, С. E.-Dr. В, HAJÓS, С. E.-Dr. J. KISS, С. E.-M. STIMM, С. E. and Dr. J. SZEPESSY, С. E. Material and structures used in water building underwent substantial changes during the past 10-15 years and are suitable for the construction of any hydraulic establishment save some of the larger individual projects. Flood protection levees are much more analyzed and known than earlier. There are different geotextilia available with predetermined filtering effects used for casing. The construction of open and closed catchwater drains, however, would need more research and development work. Riprap is sufficient and available for the need of today. There is a great assortment from gravitational-, pressure-, and drain-pipes at our disposal. There is shortage, however, in cast-iron, especially in spheric-graphite cast-iron pipes. It would be worthwhile to initiate international cooperation in this field. A problematic phenomenon is the recent - quite often experienced - failure of the Sentab pipes. This much needed and used pipe-type should be manufactured again in its former quality. Urgent action in the field cannot be longer avoided. Protection against corrosion is taken as being solved by use of the TATE procedure at wielded connections but its economic form - at the site - is not yet widespread. Active protection against corrosion seems to be necessary at points where this was not emphasized some time earlier (when the pipeline was constructed). The production of profiles and forms for pipeline construction has to be organized especially where the qualitative requirements are a prerequisite. New ratios were developed between préfabrication and renewed monolithe technologies in case of basins, reservoirs and water towers. Technological mechanization was fast during the 60s and 70s both in the field of earthworks and concrete structures. This has led to the foundation of up-to-date construction technologies. The process was ended by economic recession, and a most desired condition of the refinement of the technologies, of the economy and efficiency of development has been delayed - namely the use and introduction of small machines. For an improved technology and produce-quality the technological discipline has to be renewed. After the construction of pipelines, it was a main requirement to increase the reliability of backfill and compaction. In concrete-technology good work was supplemented by chemical additives. A correct handling of such additives would improve the quality of watertight concretes with special regard on some of the smallest fractions. As a minimum, the modernization of existing machines cannot be avoided, at least - levelpreservation. Mechanization of the manufacturing of prefabricated and prestressed systems must be completed. This is a prerequisite not only of the economy but also of quality. Maintenance of hydroprojects is often not a technical but economical problem. Organizations operated by the state budget receive 1-2 percent of the value of their assets for maintenance. This sum is definitely insufficient even for selective upkeeping determined on the basis of safety. Maintenance of riprap is not conceivable without the use of a new method : the technology of additives added in liquid concrete-pouring form and executed from a boat. To search and explore pipelines and canal-conduits non-destructive methods and the use of infratelevision must be introduced.