Papers by Keyword: Service Life

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Authors: Chien Kuo Chiu, Heui Yung Chang
Abstract: The object of this study is to propose, develop and apply a risk-based approach to determine the optimal service life for steel framed buildings in seismically active zones. The proposed framework uses models for seismic hazards, structural fragility and loss functions to estimate the system-wide costs owing to earthquake retrofitting and recovery. With the seismic risk curves (i.e. the expected seismic loss and probability of exceeding the loss), the optimal service life can be determined according to the probable maximum loss (PML) defined by the building’s owner. The risk-based approach is further illustrated by examples of 6- and 20-story steel framed buildings. The buildings have three kinds of different lateral load resisting systems, including moment resisting frames, eccentrically braced frames and buckling restrained braced frames. The results show that for the considered PML (i.e. 40% initial construction cost) and risk acceptance (e.g. 90% reliability), steel braced frames can effectively improve seismic fragility and lengthen service life for a low-rise building. However, the same effects cannot be expected in a high-rise building.
Authors: R. Jiang
Abstract: Several life measures are defined in the literature. This paper deals with defining a service life measure for a component with lognormal life. It is proposed to set the service life at the inflection of the failure rate function. The service life defined in such a way is a function of the shape parameter. This implies that the shape parameter reflects the product quality. Based on the value of the shape parameter, the component quality can be classified and the component can have different quality improvement or maintenance strategy.
Authors: Min Wu, Wai Ching Tang, Y.J. Ke, C.M. Luo
Abstract: On 29th January 2010, a tragedy took place before the blissful Chinese Lunar New Year. An old tenement building in Ma Tau Wai collapsed in a sudden, causing 2 deaths and 4 injuries. Not only did this raise peoples concerns to investigate the reasons the collapse of the tenement building, it also raised their awareness on old tenement buildings as well as protecting them from collapsing. In view of this, this paper investigates on condensation and how it might shorten the service life of that old tenement building.
Authors: Xin Yuan Zhang, Shao Chun Li, Tie Jun Zhao, Zu Quan Jin
Abstract: Water could transport aggressive substances such as carbon-dioxide, sulfates and chloride ions in reinforced concrete structures. By penetration, the stability of the whole structure is influenced. This paper deals about waterproof effect and chloride resistance of two kinds of silane coatings, polyethylene-triethoxysilane and triethoxysilane emulsions on concrete substrate along with the mechanism of the hydrophobic action. The results, in terms of visual observations, chloride test and water absorption test, showed that the two silane coatings could reduce the chloride penetration and the water absorption efficiently. The comparison between the two indicates that polyethylene-triethoxysilane penetrates little when applied on the substrate, but it performs better waterproof effect and is more efficient to chloride penetration.
Authors: Xiao Yong Wang, Han Seung Lee, Hai Moon Jung
Abstract: Chloride penetration into concrete is the main cause of steel corrosion in concrete structures exposed to chloride-rich environments. In general, conditions on the diffusion process are dominant among various penetration mechanisms, such as ionic diffusion, capillary sorption, and so on. In recent analysis of current literature, chloride diffusion is as a simplified one-dimensional diffusion process. However, for the rebar in the corner zone of concrete beam, the diffusion belongs to a two-dimensional diffusion. Based on a galerkin finite element method, a two-dimensional diffusion differential equation is built and solved numerically and the different chloride concentration is compared to one dimensional diffusion and two-dimensional diffusion process. The service life of concrete structure members under two-dimensional chloride penetration is predicted by compared with a critical threshold chloride concentration. Compared with general one-dimensional chloride attack, the service life is considerably reduced in a corner zone due to two-dimension penetration.
Authors: Li Sun, Jing Sun, Hongbo Liu
Abstract: Based on the prediction principle of the surplus service life of building’s durability and through prediction of atmospheric climate change, the data demonstrate the atmospheric environment effect will shorten the life of the building.
Authors: Pei Pei Tang, Ai Qin Shen, Meng Bo Gao
Abstract: With China's rapid economic development, traffic and heavy-duty vehicles increased significantly. Asphalt pavement failure caused by heavy traffic is increasingly prominent.Pavement's service life was greatly reduced. On the basis of extensive research and theoretical calculation the article analyzes the impact of heavy traffic on the asphalt pavement service life from three aspects of rutting,ultimate failure and fatigue failure, provides a theoretical basis for heavy traffic asphalt pavement structure design.
Authors: G.S. Abashidze, Fernand D.S. Marquis, N.M. Chikhradze
Abstract: Results of the investigation of composite materials of new type, based on basalt fiber and polyester resin, are presented, in particular, a long-term resistance of the material in corrosive media: in caustic soda as well as in sulphuric and nitric acids of 1% concentration has been estimated. The service life of given composite is recommended in above-mentioned media.
Authors: Srečko Glodež, Marko Šori
Abstract: The paper discusses the computational and experimental approach for determination of the PM gears service life concerning bending fatigue in a gear tooth root. A proposed computational model is based on the stress-life approach where the stress field in a gear tooth root is determined numerically using FEM. The experimental procedure was done on a custom made back-to-back gear testing rig. The comparison between computational and experimental results has shown that the proposed computational approach is appropriate calculation method for service life estimation of sintered gears regarding tooth root strength. Namely, it was shown that in the case of proper heat treatment of tested gears, the tooth breakage occurred inside the interval with 95 % probability of failure, which has been determined using proposed computational model.
Authors: Zdeněk Šnirch
Abstract: Paper deal with influence of on service life and degradation processes at construction of bridge piers and abutments before and after repair actions. Monitored dependencies are then reflect on degradation curves each for a singles construction characteristics (compression strength of concrete, degradation of surface, volume of carbonatation etc.) Pursuant to long-term monitoring of records from bridge piers surface diagnostic we have to be able to unite the records and use them for silicate coatings degradation dependence on bridge piers and abutments and laboratory simulated degradation.
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