Software for service life assessment of historical buildings: Implementation of coupled heat, moisture and salt transport model

2015 ◽  
Author(s):  
Jiří Maděra ◽  
Kamil Ďurana ◽  
Jan Kočí ◽  
Václav Kočí ◽  
Robert Černý
Keyword(s):  
Service Life ◽  
Transport Model ◽  
Salt Transport ◽  
Life Assessment ◽  
Historical Buildings

EFFECT OF ALKOXYSILANE-BASED TREATMENT ON THE DURABILITY OF NORTH CYPRUS STONES FOR CONSTRUCTION

2021 ◽  
Vol 16 (1) ◽  
pp. 179-196
Author(s):  
Nejdet Ziyaettin ◽  
Kübra Ekiz Barış ◽  
Leyla Tanaçan
Keyword(s):  
Service Life ◽  
Accelerated Aging ◽  
Pulse Velocity ◽  
Life Assessment ◽  
Salt Crystallization ◽  
Diffusion Resistance ◽  
Historical Buildings ◽  
Durability Properties ◽  
Northern Cyprus ◽  
Before And After

ABSTRACT Limestones are generally vulnerable to various weathering effects, hence, protection and consolidation of them is necessary. Locally available limestones of Northern Cyprus have been used in both historical buildings dated back to the 16th century for conservation applications and new buildings mostly as a cladding material. However, certain decay patterns exist on these stones. In the current study, the service life of Cyprus stones was inspected. Alkoxysilane-based consolidation and protection treatments were applied on new quarried stones to enhance the stone properties and aged stones to conserve and protect the architectural heritage. Service life assessment was performed by applying accelerated aging tests on both new and aged stones before and after treatments. The treatments improved the physical, mechanical and durability properties of the stones in terms of unchanging the water vapor diffusion resistance factor, decreasing the porosity and the water absorption ratio, increasing the ultrasound pulse velocity, the compressive and the flexural strengths, and improving the resistance of the stones against wetting-drying, freeze-thaw, salt crystallization and SO2 vapour effects. The combination of consolidation and protection treatment (K2) was more efficient on the properties of the stones compared to only protection treatment (K1) due to the better penetration capacity, higher decreasing ratio of the porosity, and higher improvement of the physical, mechanical and durability properties. The treatments also improved the properties of the aged stones; thus, it may be inferred that treatment would benefit the conservation of historical buildings.

scholarly journals The thermal history and stress state of a fresh steam-pipeline influencing its remaining service life

2011 ◽  
Vol 15 (3) ◽  
pp. 691-704 ◽  
Author(s):  
Gordana Bakic ◽  
Vera Sijacki-Zeravcic ◽  
Milos Djukic ◽  
Stevan Maksimovic ◽  
Dusan Plesinac ◽  
...  
Keyword(s):  
Service Life ◽  
Elevated Temperatures ◽  
Operating Temperature ◽  
Life Assessment ◽  
Temperature History ◽  
Significant Variable ◽  
Remaining Life ◽  
Pipe Bend ◽  
Steam Pipeline ◽  
Remaining Life Assessment

The service life of thick-walled power plant components exposed to creep, as is the case with pipelines of fresh- and re-heated steam, depend on the exhaustion rate of the material. Plant operation at elevated temperatures and at temperatures below designed temperatures all relates to the material exhaustion rate, thus complicating remaining life assessment, whereas the operating temperature variation is a most common cause in the mismatching of real service- and design life. Apart from temperature, the tube wall stress is a significant variable for remaining life assessment, whose calculation depends on the selected procedure, due to the complex pipeline configuration. In this paper, a remaining life assessment is performed according to the Larson-Miller parametric relation for a ?324?36 pipe bend element of a fresh steam-pipeline, made of steel class 1Cr0.3Mo0.25V, after 160 000 hours of operation. The temperature history of the pipeline, altogether with the pipe bend, is determined based on continuous temperature monitoring records. Compared results of remaining life assessment are displayed for monitored temperature records and for designed operating temperature in the same time period. The stress calculation in the pipe bend wall is performed by three methods that are usually applied so to emphasize the differences in the obtained results of remaining life assessment.

scholarly journals Modeling the mechanical wear of the contact elements of pantograph during high-speed movement

2020 ◽  
Vol 157 ◽  
pp. 01022
Author(s):  
Victor Philippov ◽  
Alexandr Smerdin
Keyword(s):  
Service Life ◽  
High Speed ◽  
Theoretical Calculations ◽  
Experimental Studies ◽  
Maximum Error ◽  
Life Assessment ◽  
Rolling Stock ◽  
Mechanical Wear ◽  
Wear Process ◽  
Mechanical Component

The use of contact elements with an extended service life is one of the most economical and least costly ways to ensure reliable, economical and environmentally friendly transmission of electricity to rolling stock. To evaluate the service life in OSTU, a methodology for conducting experimental studies of contact pairs of pantograph has been developed and successfully tested, involving bench tests for each pair of contact materials “contact insert - contact wire” in order to determine their optimal combination to reduce wear and increase service life. Assessment of the amount of wear and prediction of the life of the contact elements are made, including using mathematical modeling. The purpose of this article is to improve the mechanical component of the wear model of the contact elements of pantograph in high-speed conditions. The results of experimental studies and theoretical calculations of the mechanical wear of contact elements are presented. The analysis of the graphs allows us to conclude that it is possible to use an improved mathematical model for modeling the mechanical component of the wear process of the elements of contact pairs with a maximum error value of not more than 5%.

scholarly journals Service-Life Assessment of Existing Precast Concrete Structure Exposed to Severe Marine Conditions

2016 ◽  
Vol 30 (3) ◽  
pp. 04015036 ◽  
Author(s):  
I. Segura ◽  
S. Cavalaro ◽  
A. de la Fuente ◽  
A. Aguado ◽  
V. Alegre
Keyword(s):  
Service Life ◽  
Concrete Structure ◽  
Precast Concrete ◽  
Life Assessment
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