scholarly journals Restoration corrosion survey of the steel structure of peron hall of the Main railway station in Prague

2019 ◽  
Vol 63 (1) ◽  
pp. 1-10
Author(s):  
P. Pokorný ◽  
M. Hrabánek ◽  
H. Geiplová
Keyword(s):  
Chemical Composition ◽  
Protective Coating ◽  
Steel Structure ◽  
Corrosion Damage ◽  
Coating System ◽  
Railway Station ◽  
Restoration Project ◽  
Roof Structure ◽  
Current State ◽  
Bearing Structure

Abstract This article presents the results of the corrosion survey of the load-bearing structure of the main hall of the Main railway station in Prague. The chemical composition and microscopy view of the metal alloy has been explored, the current state of the anti-corrosion protection system as well as its composition were also evaluated. The corrosion damage of sheets and reinforcements of individual columns of the peron hall is also reported. The corrosion damage of the plates and reinforcements is locally very significant and is related to the drainage of rain water from the damaged roof structure. Renovation is also necessary for the protective coating system. The article concludes a restoration project that fully respects the historical form of the construction of the early twentieth century with minimal compromise.

scholarly journals Corrosion survey of the palm greenhouse support structure in the castle garden in Lány

2019 ◽  
Vol 63 (1) ◽  
pp. 54-64
Author(s):  
P. Pokorný ◽  
M. Hrabánek ◽  
D. Dvorský ◽  
L. Turek
Keyword(s):  
Corrosion Resistance ◽  
Cast Iron ◽  
Chemical Composition ◽  
Point Of View ◽  
Coating System ◽  
Current State ◽  
Steel Cast ◽  
Metal Materials ◽  
Static Point ◽  
Applied Coating

Abstract The corrosion survey of the supporting steel/cast iron structure of the palm greenhouse included not only the characteristics of the used metal materials (microstructure, chemical composition), but also the current state of the system of corrosion protection (thickness and stratigraphy of the applied coating system). From a static point of view, the palm greenhouse design meets the applicable standards if two damaged cast iron columns are repaired. A new top coat with extended corrosion resistance is required on the surface of individual metal profiles.

Preservation of the Large Timber Roof of the Porta Nuova Railway Station in Torino

2013 ◽  
Vol 778 ◽  
pp. 951-958 ◽  
Author(s):  
Clara Bertolini-Cestari ◽  
Stefano Invernizzi ◽  
Tanja Marzi ◽  
Steni Rolla
Keyword(s):  
Cultural Heritage ◽  
Point Of View ◽  
Timber Structure ◽  
Structural Assessment ◽  
Railway Station ◽  
Roof Structure ◽  
Maintenance Program ◽  
Bearing Structure ◽  
Important Structure ◽  
Design And Construction

Torino, in 1861, was the first capital of the just unified Reign of Italy. In the same year, Eng. A. Mazzucchetti was charged for the design of the railway station of Porta Nuova in Torino, in correspondence of the arrival of the railway connecting Genova. The original conception resembles the bilateral scheme of the King Cross station in London, which is few years older. The design and construction of the station deserved contributions from the most outstanding scientists of that time, including R. Sephenson who provided the details of the lateral roof structures of the station, and the young Eng. A. Castigliano who defended his thesis on the design of the great steel vault above the rails. The two main branches were conceived with masonry bearing structure and a wide span timber roof covered with stone plates. The station, during the years, was object of several interventions, including restorations, dismantling of parts, and changes in the destination of use. Nowadays, the roof structure needs for important maintenance interventions due to the water leaking which caused the deterioration of the beneath timber structure. The present holders are considering the replacement of the entire roof. This solution is not respectful for conservation criteria, nor is affordable from an economical point of view. The present study describes the correct and sustainable approach for the structural assessment, restoration and maintenance program for the preservation of this important structure belonging to cultural heritage.

Study of the character and causes of destruction of the cardan shaft of the propeller engine

2019 ◽  
Vol 85 (12) ◽  
pp. 43-50
Author(s):  
D. A. Movenko ◽  
L. V. Morozova ◽  
S. V. Shurtakov
Keyword(s):  
Mechanical Properties ◽  
Chemical Composition ◽  
Yield Point ◽  
Protective Coating ◽  
Fracture Pattern ◽  
Corrosion Cracking ◽  
Tempered Martensite ◽  
Neck Formation ◽  
Static Mechanism ◽  
Shaft Surface

The results of studying operational destruction of a high-loaded cardan shaft of the propeller engine made of steel 38KhN3MFA are presented to elucidate the cause of damage and develop a set of recommendations and measures aimed at elimination of adverse factors. Methods of scanning electron and optical microscopy, as well as X-ray spectral microanalysis are used to determine the mechanical properties, chemical composition, microstructure, and fracture pattern of cardan shaft fragments. It is shown that the mechanical properties and chemical composition of the material correspond to the requirements of the regulatory documentation, defects of metallurgical origin both in the shaft metal and in the fractures are absent. The microstructure of the studied shaft fragments is tempered martensite. Fractographic analysis revealed that the destruction of cardan shaft occurred by a static mechanism. The fracture surface is coated with corrosion products. The revealed cracks developed by the mechanism of corrosion cracking due to violation of the protective coating on the shaft. The results of the study showed that the destruction of the cardan shaft of a propeller engine made of steel 38Kh3MFA occurred due to formation and development of spiral cracks by the mechanism of stress corrosion cracking under loads below the yield point of steel. The reason for «neck» formation upon destruction of the shaft fragment is attributed to the yield point of steel attained during operation. Regular preventive inspections are recommended to assess the safety of the protective coating on the shaft surface to exclude formation and development of corrosion cracks.

scholarly journals PtIr protective coating system for precision glass molding tools: Design, evaluation and mechanism of degradation

2020 ◽  
Vol 385 ◽  
pp. 125378 ◽  
Author(s):  
Marcel Friedrichs ◽  
Zirong Peng ◽  
Tim Grunwald ◽  
Michael Rohwerder ◽  
Baptiste Gault ◽  
...  
Keyword(s):  
Protective Coating ◽  
Design Evaluation ◽  
Coating System ◽  
Glass Molding ◽  
Precision Glass Molding ◽  
Mechanism Of Degradation

Extraction of Nickel and Cobalt from Nickel Slag Wastes by the Thermo-Diffusion Method

2020 ◽  
Vol 299 ◽  
pp. 1134-1138
Author(s):  
S.A. Laihan ◽  
A.A. Veselovsky
Keyword(s):  
Chemical Composition ◽  
Southern Urals ◽  
Diffusion Method ◽  
Waste Processing ◽  
The Southern Urals ◽  
Iron Cobalt ◽  
Current State ◽  
Cobalt Nickel ◽  
Average Analysis ◽  
Slag Waste

The current state of the issue of the slag waste processing was considered, using the example of the Southern Urals Nickel Plant. The average analysis of the chemical composition of the slag was performed; the determined phases contained iron, cobalt, nickel and chromium. The maps of the distribution of these elements in the slag were obtained.

scholarly journals Analysis of load bearing structure of selected hall buildings

2019 ◽  
Vol 284 ◽  
pp. 09005
Author(s):  
Sławomir Onopiuk ◽  
Adam Stolarski
Keyword(s):  
Heavy Rainfall ◽  
Drainage System ◽  
Design Stage ◽  
Direct Result ◽  
Construction Process ◽  
Roof Structure ◽  
Under Construction ◽  
Bearing Structure ◽  
Construction Works ◽  
Correct Design

In this paper the issues associated with correct design of hall buildings has been presented. Large span roof structures require a particularly careful approach to design issues. In this paper examples of two building hall were presented. In the first example, the construction disaster occurred, while in the second of presented buildings due to the changes introduced while construction has been protected against such disaster. The first of the analyzed cause concerns storage hall, whose roof structure has been destroyed due to heavy rainfall. The main cause of this disaster was the malfunction of vacuum roof drainage system compounded by a number of design errors. Mentioned errors were not eliminated, during construction, despite the additional investor supervision, which was independent of parties involved in a construction process. The second case concerns the structure of a sports hall, which was built next to the existing school. Under construction of the hall building, the contractor and the supervision inspector, in conjunction with the designer, introduced a number of modifications of the structure to prevent the disaster. These modifications were a direct result of errors at the design stage, which were eliminated under the construction works. Based on analyzed cases, the scope of diagnostics, which should be performed during the operation of hall buildings with large roof areas, was determined.

Formation Mechanism of the Frictionally-Formed Protective Coating by Using Self-Repairing Material under Sliding Friction

2008 ◽  
Vol 373-374 ◽  
pp. 572-575 ◽  
Author(s):  
Wen Gang Chen ◽  
Yu Zhou Gao ◽  
Hui Chen Zhang ◽  
Y.J. He
Keyword(s):  
Chemical Composition ◽  
Protective Coating ◽  
Friction And Wear ◽  
Steel Surface ◽  
Sliding Friction ◽  
Ambient Condition ◽  
Flash Temperature ◽  
Sliding Direction ◽  
Surface Topographies ◽  
Worn Surface

Sliding experiments lubricated with hydroxyl silicate magnesium particles as additive were performed under ambient condition and different loads by using an AMSLER friction and wear tester. The surface topographies and compositions of worn surface of 45 steel rings were analyzed by SEM and EDAX. The experimental results show that the friction load had great effect on generation of the frictionally-formed protective coating. No protective coating formed on the worn steel surface under lower friction load. However, a smooth and continuous protective coating can be developed on the worn surface of the steel when the friction load is high enough. The chemical composition of the protective coating is roughly the same as the additive. The additive can be fractured, stretched and flowed along the sliding direction under high contacting stress and instantaneous flash temperature, which result in coating being formed.

Experiment of the SCT Joint under Complicated Loading

2011 ◽  
Vol 255-260 ◽  
pp. 607-613
Author(s):  
Bing Liao ◽  
Yong Feng Luo ◽  
Xiao Nong Guo
Keyword(s):  
Bearing Capacity ◽  
Loading Condition ◽  
Steel Structure ◽  
Force Transmission ◽  
Load Bearing Capacity ◽  
Load Bearing ◽  
Roof Structure ◽  
Axial Forces ◽  
Out Of Plane ◽  
Water Sports

A radial-circle-lined grid shell, its height changed step by step in the radial direction, is adopted in the roof steel structure of the Citizen Water Sports Center in Jiangyin, China. And the Spatial Crossing Tubular (SCT) joint is used for the connection of pipe members. Because the force transmission in the roof structure is different from the traditional truss structure, a lot of SCT joints are in a complicated loading state. The joint forces include axial forces and in/out-of-plane moments. To investigate the mechanical behavior and the load-bearing capacity of a typical SCT joint in such complicated loading condition, a full size model test of the typical SCT joint is conducted. The test process is summarized in the paper, together with the finite element calculation of the typical SCT joint in test conditions. By comparing the numerical results with the test results, several significant parameters of the connection are investigated, including the stiffness change of the joint, the transmission mechanism of forces, the ultimate load-bearing capacity and the failure mode of the joint. After investigation, several useful suggestions are proposed for the SCT joint design. They are also valuable for the design of similar SCT joints under complicated loading condition.

Construction Technology of Large-Span Hybrid Structure of Suspendome with Stacked Arch in Chiping Gymnasium

2011 ◽  
Vol 243-249 ◽  
pp. 6083-6086 ◽  
Author(s):  
Xiao Bei Wang ◽  
Zhen Hua Liu ◽  
Ming Gong ◽  
Lian Fen Weng
Keyword(s):  
High Altitude ◽  
Steel Structure ◽  
Hybrid Structure ◽  
Construction Technology ◽  
Large Span ◽  
Finite Element Software ◽  
Roof Structure ◽  
Temporary Support ◽  
Stress And Deformation ◽  
Lattice Shell

Large-span hybrid structure of suspendome with stacked arch is applied into steel roof of Chiping Gymnasium. The construction of this new type structure system is difficult according to structure characteristics such as its large-span stacked arch, high installation altitude, lattice shell installation, prestressed cable tension, and tight construction period. Temporary support frame, segment lifting and high altitude splicing construction method is adopted to install the stacked arch, and total support, high-altitude spread operation method is used to install lattice dome. A spatial structural analysis is conducted on the supporting system, and the finite element software is adopted to simulate and analyze the installation process of the steel structure roof system. At the same time, stress and deformation of the roof structure are monitored by precise instruments and equipments. As the result, construction safety and quality are guaranteed.

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