Background: The security of the state is a priority task in science in modern conditions. Transportation area as one of the most important areas for the state sustainable functioning, requires the special attention. It is very important to research scientific approaches and their implementation for providing security at transport. Due to the large concentration of passengers at station complexes, special attention should be paid to keeping them in working condition. Visual inspection of the actual technical condition (full-scale inspection and measurement) of all structural elements (joints, joints of floor slabs, nodes, joints) of a bomb shelter is carried out to identify existing defects, damages and assess their impact on the safety, durability and serviceability of the bomb shelter. The article contains a description of the construction of civil defence underground structures, namely: floor slabs, bomb shelter load-bearing elements, internal waterproofing, and special engineering equipment. The condition of these elements of the bomb shelter at the time of the survey is evaluated, and the existing defects and damages are characterized. The main defects are concrete leaching with exposed reinforcement, cracks and spalling of concrete, lack of modern waterproofing, partial destruction of supporting structures. Based on the results, recommendations for further operation of the structure are formulated. And also proposed a set of measures to eliminate existing violations and further exploitation of underground structures. Recommended a set of works to repair the individual components and structures: pasting modern waterproofing materials, the elimination of minor damages to reinforced concrete structures, restoration of the protective layer of concrete to its design values. Aim: consideration of methods of full-scale examination of bomb shelters, nderground structures and their application; definition of the technical condition of the structure; development of recommendations for further operation. Materials and Methods: As a material and input data, asylum No. 6 in Moscow was analyzed, fixing of defects was carried out. The field method was used as the main one: collection and analysis of preliminary information about the structure, measurement of structures, visual inspection of structures, description of the main defects, establishment of causes, forecast of development and recommendations on elimination of the existing damages. The article puts more emphasis on the visual inspection and assessment of damages: denudation of reinforcement and poor quality waterproofing, leaching of concrete at the points of contact with ground water, corrosion of reinforcement in reinforced concrete, partial collapse of structures, etc. Results: As a result of the surveys, a recommendation list was compiled to bring the technical and economic indicators of the structure to the standard state. Conclusion: according to the results of the survey, it is recommended to perform construction and installation work at the stage of "Repair"
Introduction. An on-site inspection method is a visual examination of an engineering structure aimed at the detection of defects, damages, and disturbances of a construction facility and further issuance of recommendations for their elimination. An on-site inspection method is among the principal ones applied, as it serves to identify all defects of bridge structures during their service lives. Materials and methods. The structures of the bridge over the Kosopasha river, located at the 5+910 km of the Pasha – Sviritsa – Zagubye motor road, the Volkhov District, Leningrad Region, were inspected. An on-site inspection method was applied to collect the information and perform the preliminary analysis. Results. The co-authors described the construction of the bridge elements, including the road deck topping, expansion joints, the safety parapet, sidewalks, hand rails, water insulation, the drain line, the bridge approach, the span, bridge support structures, piers, the bridge abutment, and the under-bridge area. They analyzed the condition of these elements at the time of their inspection; they compiled a report on defects, damages and the bridge deck capacity. The main defects include concrete leaching accompanied by concrete reinforcement denuding, concrete cracking and chipping, absence of safety parapet, partial destruction of rails, and failure of abutment strengthening constructions. Conclusions. Recommendations for the further operation of the bridge were formulated on the basis of inspection results. A set of measures is proposed with the purpose of eliminating the defects and further safe operation of the bridge structure. The recommendations include a set of repair works in respect of particular joints and constructions: removal of dust and dirt from the elements of the bridge topping and sidewalks, repair of minor damages of reinforced concrete structures, shore protection aimed at abutment reconstruction, installation of the safety parapet.
The article presents the results of studies of innovative materials in the field of testing frost resistance. In fact, present accelerated methods for the determination of concrete frost resistance have high labour consuming and low effectiveness. Moreover there is no such accelerated methods which can be sufficiently applicable fro different innovative concretes, for example, concretes with SAP or self-compacting concrete and so on. Therefore, it is highly important to investigate new accelerated test method with high operability, efficiency and sufficient precision. Previously, two new methods were developed. The main purpose of the research is to compare these methods by evaluation of their technology and accuracy and, consequently, to identify the more sustain and efficient one. First method is based on estimation of energy release due to mechanical fracture and thermo cycling. Second method consists of the calculation value z (relation between relative decreasing of strength and relative strain in the direction perpendicular to compression) and replacement of thermo cycles by mechanical cycles. Both methods have high operability and do not take a lot of time, in was tested on the 10 specimens made of concrete and results were compared with values derived by standard method.
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