994 resultados para Ground supported slabs
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Acknowledgements. This study was supported by the FP7-PEOPLE-2013-IEF Marie-Curie Action – SPATFOREST. Tree data from BCI were provided by the Center for Tropical Forest Science of the Smithsonian Tropical Research Institute and the primary granting agencies that have supported the BCI plot tree census. Data for the liana censuses were supported by the US National Science Foundation grants: DEB-0613666, DEB-0845071, and DEB-1019436 (to SAS). Soil data was funded by the National Science Foundation grants DEB021104, DEB021115, DEB0212284 and DEB0212818 supporting soils mapping in the BCI plot. We thank Helene Muller-Landau for providing some data on tree height for some BCI trees. We also thank all the people that contributed to obtain the data.
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This research was supported by the Formación de Profesorado Universitario FPU13/05837 (Ministerio de Educación Cultura y Deporte) program, by the OAPN 053/2010 (Organismo Autónomo Parques Nacionales, MAGRAMA) project, by the I + D + I CGL2015-68144-R (Ministerio de Economia y Competitividad) project, by the Leverhulme Trust International Network Grant IN-2012-140 and the Royal Geographical Society Dudley Stamp Memorial Award.
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With ever increasing demands to strengthen existing reinforced concrete structures to facilitate higher loading due to change of use and to extend service lifetime, the use of fibre reinforced polymers (FRPs) in structural retrofitting offers an opportunity to achieve these aims. To date, most research in this area has focussed on the use of glass fibre reinforced polymer (GFRP) and carbon fibre reinforced polymer (CFRP), with relatively little on the use of basalt fibre reinforced polymer (BFRP) as a suitable strengthening material. In addition, most previous research has been carried out using simply supported elements, which have not considered the beneficial influence of in-plane lateral restraint, as experienced within a framed building structure. Furthermore, by installing FRPs using the near surface mounted (NSM) technique, disturbance to the existing structure can be minimised.
This paper outlines BFRP NSM strengthening of one third scale laterally restrained floor slabs which reflect the inherent insitu compressive membrane action (CMA) in such slabs. The span-to-depth ratios of the test slabs were 20 and 15 and all were constructed with normal strength concrete (~40N/mm2) and 0.15% steel reinforcement. 0.10% BFRP was used in the retrofitted samples, which were compared with unretrofitted control samples. In addition, the bond strength of BFRP bars bonded into concrete was investigated over a range of bond lengths with two different adhesive thicknesses. This involved using an articulated beam arrangement in order to establish optimum bond characteristics for use in strengthening slab samples.
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There are many studies that reveal the nature of design thinking and the nature of conceptual design as distinct from detailed or embodiment design. The results can assist in our understanding of how the process of design can be supported and how new technologies can be introduced into the workplace. Existing studies provide limited information about the nature of collaborative design as it takes place on the ground and in the actual working context. How to provide appropriate and effective of support for collaborative design information sharing across companies, countries and heterogeneous computer systems is a key issue. As data are passed between designers and the computer systems they employ, many exchanges are made. These exchanges may be used to establish measures of the benefits that new support systems can bring. Collaboration support tools represent a fast growing section of the commercial software market place and a reasonable range of products are available. Many of them offer significant application to design for the support of distributed meetings by the provision of video and audio communications and the sharing of information, including collaborative sketching. The tools that specifically support 3D models and other very design specific features are less common and many of those are in prototype stages of development. A key question is to find viable ways of combining design information visualisation support with the collaboration support technologies that can be seen today. When collaborating, different views will need to be accessible at different times to all the collaborators. The architects may want to explain some ideas on their model, the structural engineers on their model and so on. However, there are issues of ownership when the structural engineer wants to manipulate the architect’s model and vice versa. The modes of working, synchronous or asynchronous may have a bearing as in a synchronous session there is control of what is happening.
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Shrinkage cracking is commonly observed in concrete flat structures such as highway pavements, slabs, and bridge decks. Crack spacing due to shrinkage has received considerable attention for many years [1-3]. However, some aspects concerning the mechanism of crack spacing still remain un-clear. Though it is well known that the interval of the cracks generally falls with a range, no satisfactory explanation has been put forward as to why the minimum spacing exists.
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The theme of this conference comes from the epitaph on the Lewis Carroll’s gravesite. “Is All our Life then But A Dream?” This seems fitting for a time when so much change in the terrain of English makes us feel as if we are somnambulating through a surrealist landscape. Like Lewis Carroll’s Alice, (Carroll, 2003) we might find ourselves at strange tea parties with bureaucratic mad hatters, and just when we think we have a grasp of applying new theory in our teaching, we fall down another rabbit hole, to swim in confusion as some queen calls out, ‘off with their heads!’. The shifting ground in English inevitably moves in response to waves of theory influencing classroom practice. Each new paradigm has claimed to liberate language learners from the flaws of the previous model. Each linguist or literary theorist who shaped the new paradigm no doubt dreamt of a new population emerging from school as more powerfully literate citizens than the previous generation.
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In this work, natural palygorskite impregnated with zero-valent iron (ZVI) was prepared and characterised. The combination of ZVI particles on surface of fibrous palygorskite can help to overcome the disadvantage of ultra-fine powders which may have strong tendency to agglomerate into larger particles, resulting in an adverse effect on both effective surface area and catalyst performance. There is a significant increase of methylene blue (MB) decolourized efficiency on acid treated palygorskite with ZVI grafted, within 5 mins, the concentration of MB in the solution was decreased from 94 mg/L to around 20 mg/L and the equilibration was reached at about 30 to 60 mins with only around 10 mg/L MB remained in solution. Changes in the surface and structure of prepared materials were characterized using X-ray diffraction (XRD), infrared (IR) spectroscopy, surface analysing and scanning electron microscopy (SEM) with element analysis and mapping. Comparing with zero-valent iron and palygorskite, the presence of zero-valent iron reactive species on the palygorskite surface strongly increases the decolourization capacity for methylene blue, and it is significant for providing novel modified clay catalyst materials for the removal of organic contaminants from waste water.