Key Engineering Materials Vol. 517

Abstract: The wooden shan-jia structure (The braced arch structure), the main load-bearing structure in the traditional tile board room of Yi minority, is one of the residential elements which are most distinctive and most valuable to be protected. As the traditional architectural culture of the Yi, the structure is still being widely used in local residence, but the Liangshan Yi Minority is located in high intensity earthquake zone, which cause large security risks on the wooden frame system. In this paper, three kinds of common and typical layouts of braced arch structure are collected after investigating of the wooden shan-jia structure. The structural weaknesses are found through the simulation of ANSYS. Finally, propose some measures to optimize the structural design, in order to enhance the seismic optimization and improve the construction technology of tile board room.

Abstract: Significant advances in the development and customization of various sophisticated technologies for structural monitoring have emerged during the last decade. Technologies for instrumentation, monitoring, load testing, non-destructive evaluation and/or characterization, three-dimensional finite element modeling and various types of analyses have now become available at a reasonable cost. Within this framework, the paper focuses the issues addressed in designing a sensors network for dynamic monitoring of a historic swing bridge in Taranto (Italy).

Abstract: This paper presents a case study on the carbon footprint of a fibre reinforced polymer (FRP)-incorporated pedestrian bridge in comparison with a conventional prestressed concrete (PC) one. The CO₂ emission is used as an index and calculated for both the material manufacturing and the construction processes. It is shown that using an FRP-incorporated pedestrian bridge to replace a conventional prestressed concrete (PC) bridge may reduce the CO₂ emission by 18% and 70%, respectively, during the material manufacturing and construction periods, leading to a total reduction by about 26%. Such reduction is expected to be more significant if the life-cycle CO₂ emission is accounted for, since the former type of bridge is free of corrosion and almost maintenance-free. Therefore, FRP-incorporated bridges may become a more competitive alternative to conventional reinforced concrete (RC) or PC ones with the increasing attention paid on the sustainability and environmental friendliness of construction industry by our society.

Abstract: In order to obtain better social and economic benefits, non-traditional materials and technologies must be closely integrated with non-traditional research mode. Traditional studies on materials and techniques are mainly undertaken by engineers of structures and materials, while architects play the role in the application of materials and technologies. Therefore, the application of new materials and technologies shall be inevitably accepted, well acquainted with and proficiently utilized by architects. The three factors that have a major impact on this process are the complexity, differentiation and timeliness, indicating that the application of new materials and technologies is simpler, similar to the application method of traditional materials and technologies and can be learned and mastered by architects in a short time. The hardcore of non-traditional research mode is the close coordination between architects and the engineers of structure and materials, the design methods and technical details that adapt to new materials and technologies.

Abstract: Waste silica remaining after the Carbon Capture and Storage by Mineral carbonation (CCSM) could represent a potential pozzolan material for partial replacement in concrete. The objective of this work was the production and testing of cement gel cubes with the residual-silica by-product obtained from the accelerated carbonation of Mg-silicate rocks. The silica produced was characterised in terms of its chemical composition, morphology and LOI. Also, the silica was used as an additive to the cement (CEM I class) in order to assess the effect on (28 days) compressive strength in comparison with a cement control specimen. The influence of different cement replacement percentages (5% and 10wt.% silica) were determined by measuring initial setting times and compressive strength. The compressive strength of the cement specimens with 5 and 10wt.% silica as pozzolan replacement of Portland cement were 3% and 8% higher than the control cubes indicating that the residual silica powder may have pozzolanic properties. However, high LOI and magnesium content might represent a limit in high-end applications and further work is required to identify optimised CCSM conditions able to reduce the impurities in the silica by-product and to establish their potential as a pozzolan.

Abstract: Considering the dynamical characteristic of structure under different earthquake hazard level, inelastic demand curves, namely, inter-story shear versus inter-story displacement curve are established by using mode spectrum method. Based on the relation of structure performance object and displacement ductibility, the relation of structure performance object and inter-story demand curve is established. And the inter-story demand curves take into account the inelastic behavior of structure under earthquake action adequately. Then considering the seismic respond characteristic and the capacity curve of the frame structure a new method named inter-story capacity spectrum (ISCS) is put forward for the performance based seismic design of vertically irregular frame structures. Examples are presented to demonstrate the applicability and utility of the proposed method. In part , the procedure to establish the ISCS method is mainly explained. And the examples will be introduced in part .

Abstract: The procedure to establish the inter-story capacity spectrum method is explained detailedly in partⅠ. In this part examples are presented to demonstrate the applicability and utility of the proposed method. It is shown that the vertically irregular RC frame structure can be directly designed with the methodology proposed in this work. It is also concluded that the new method can control the inter-story drift, the order and position of hinges of vertically irregular structures under different earthquake hazard level. Comparing to time history analysis method, it leans to cautious and is superior to direct displacement-based design (DDBD).

Abstract: Conventional plastics derived from the fossil fuels pose a threat to the global environment due to their non-degradable nature. Problems associated with global warming and solid waste management has generated interest in the development of novel plastics. Theses while retaining the desired properties of conventional synthetic plastics must also are degradable. Among the various biodegradable plastic available, there is growing interest in the group of polymers known as polyhydroxyalkanoate (PHA).The present investigation is based on (i) Biodegradation of Bioplastic with biological approaches (ii) Production of cost effective Bioplastic. Cost of bioplastics serves as a hindrance to the development of bioplastics for food and drink packaging as the plastic is produced by harvesting the natural resources thus there is utilization of the agricultural waste and also reduces the overall cost of the product. As in the case of petroleum based plastic production, there is the need of huge sum of energy which consumes the non renewable sources which is getting depleted. Thus, we can conclude that having a cost effective bioplastic in our near future. This plastic will be replacing the commercially available plastic very soon. The bioplastic produced is also degradable. It thus reduces the waste accumulation on the areas surrounding us. It is also suggested that on degradation it does not produces any toxic to the environment and no harmful gas is emitted thus no greenhouse gas and no global warming. This would be an environment friendly product.

Abstract: In order to increase live-load carrying capacity and life of bridges, aluminum alloy bridge decks have been widely used in bridge structures for more than 70 years because of the features of high strength-to-weight ratio, excellent corrosion resistance, ease of fabrication and recovery, rapid construction, maintenance-free and cost effective. First, this paper provides in detail the advantages of aluminum alloy bridge decks and the main areas of aluminum alloy applications in bridges can also be pointed out. Then, a brief overview of typical application examples and structural shapes of aluminum alloy bridge decks are introduced. At the same time, a state-of-the-art review on the researches of aluminum alloy bridge decks, related to static behaviors, fatigue properties, dynamic responses, structural systems and cost effective, is presented. Finally, the perspectives of research and development on aluminum alloy bridge decks are discussed.

Abstract: Because it is difficult to monitor the quality of gravel pile (the length, the diameter) in composite foundation, the method of radar is put forward. Numerical simulations of radar monitoring on flexural pile are processed. The results show that the method of radar monitoring can be used to check the quality of gravel piles (length, diameter) accurately. Then this technology is applied in some highway project. By comparing with the results of another company, the characteristics including high precision and speed are found. So the technology can be far and wide used.