Pshinko P. Improvement of reliability for railway reinforced concrete sleepers

текстThe subject of inquiry is the railroad reinforced-concrete sleepers for the conditions of accelerated motion and high-speed traffic of the railroad transport. The aim of the thesis work: the increasing of the railroad reinforced-concrete sleepers' reliability at the expense of the improvement of their construction and physical-mechanical properties of the concrete on the basis of the development of the railroad reinforced-concrete sleepers' reliability assessment model depending on the determining factors. The investigation methods: methods of field observation and statistic analysis, methods of numerical simulation of the reinforced concrete constructions, methods of the reinforced concrete theory, methods of the reliability theory; standard methods of the concrete raw materials investigation; standard methods of investigation of the physical-mechanical properties of the concrete, methods of the technical and economic assessment of the industrial products life. The theoretical and practical results: the statistic data on the defects and damages of the railroad reinforced-concrete sleepers and on the reasons of their appearance were received; the reinforcement efficient diagram of the sleepers' construction of SB3-0 type which allows increase the sleepers' reliability was worked out; the optimal compositions of the concrete mix using the complex chemical additive PLKP was worked out. The scientific novelty: the regularities of the railroad reinforced-concrete sleepers' defects and damages appearance were determined on the basis of the performed statistic analysis; the load levels on the reinforced-concrete at today's and prospective traffic speeds (received further development) were determined; the properties of the mode of deformation of the railroad reinforced-concrete sleepers under the conditions of the accelerated and high-speed traffic of the passenger trains (received for the first time) were determined; the ranking of the factors and the railroad reinforced-concrete sleepers' construction reliability assessment under the conditions of the development of the rolling stock prospective speeds (received for the first time) were performed; the investigation of the concrete for the railroad reinforced-concrete sleepers' the effectiveness of the chemical additive PLKP was performed; the peculiarities of the railroad reinforced-concrete sleepers' reinforcement diagram influence on the concrete homogeneity (received for the first time) were revealed; the reliability of the railroad reinforced-concrete sleepers was increased. Introduction degree: introduced to the technological process of the railroad reinforced-concrete sleepers manufacture at the Private Joint-Stock Company "Zaporizhzhia Plant of Reinforced-Concrete Sleepers"; estimated affordability of the work results introduction to the production is in the expenses reduction by 6.5% at service of the sleepers with improved reliability as compared with the analogs. Scope: construction of traffic facilities.