Advanced Materials Research Vols. 450-451

Abstract: Diagrid structures are widely used for today’s tall buildings due to their distinguished architectural aesthetics in any existing urban context and structural efficiency in carrying lateral loads. With prevalent emergence of complex-shaped buildings throughout the world, this paper investigates structural efficiency of diagrid structures employed for complex-shaped tall buildings, such as twisted, tilted and freeform towers. For each complex form category, tall buildings are designed with diagrid systems, and their structural efficiency is studied in conjunction with building forms. In order to investigate the impacts of various important geometric configurations of complex-shaped tall buildings, parametric models are generated using appropriate computer programs, and the models are exported to structural engineering software for design and analyses. Based on the study results, structural efficiency of diagrids for tall buildings of each complex form category is estimated.

Abstract: The paper is under the background of residence architecture and Tibetan culture, taking the settlements and architecture of Zhonglu Danba as the object of research, taking architectural culture of other ethnic groups as reference. Inspect the vernacular architecture on the aspects of architecture and culturology, and to conclude the common ecological wisdom in residence construction. The paper also does case study of renewal, revise the traditional architecture aim at the flaws, giving the idea of” excessive growth”, in order to fulfill the demand of local resident.

Abstract: Previous studies have demonstrated that users’ evaluation of acoustic environment such as subjective loudness or acoustic comfort depends on a series of factors in a particular space, rather than only on sound pressure levels. In this study, more than 2800 interviews have been undertaken at underground spaces in Harbin, China, to find out influencing factors to users’ evaluation, considering both space conditions and demographical factors. Based on the analysis of case study results, it has been found that in underground spaces, background music is generally noticeable and preferred, and it is useful for psychologically ‘masking’ other less preferred sound sources. While there is a linear correlation between the measured LAeq and the subjective loudness, the relationship between the measured LAeq and the acoustic comfort evaluation is of a parabolic shape, and the acoustic comfort is the best when LAeq is around 65-70dB. There is no significant difference between different age groups, whereas people with a higher income level tend to feel that an underground space is nosier and less acoustically comfortable.

Abstract: A novel nonflammable thermal insulation material for buildings was prepared by foaming sodium silicate solution with blowing agent. The material density is 274 kg/m3,with the compressive strength up to 2.0MPa and the coefficient of heat conductivity low to 0.08 W/ m•K.

Abstract: Plastic fastener is a typical strengthening material for museum movable cultural relics in China.To find out strengthening effects of this material,by shaking table tests seismic responses of a ceramic relic in a 1:1 scale showcase model were studied.2 boundary conditions of the relic were considered:free-standing and strengthened by plastic fastener. By white noise excitation basic frequency of the showcase was obtained; by inputting El-centro earthquake waves of different intensities,seismic responses of both showcase and relic were studied,aseismic results of plastic fasteners were discussed. By simulation method finite element models for the showcase and strengthened relic were built,modal as well as time history analyses were carried out to validate the effectivity of shaking table tests.Results show that prominent frequency ingredients of the showcase are far greater than those of the input earthquake waves,thus the showcase is not damaged seriously; for the relic after it is strengthened by plastic fasteners,its peak displacement and acceleration response values decrease,which still embody obviously under strong earthquakes.Thus by plastic fasteners the relic can be effectively strengthened. Besides,simulation results are well in accordance with those of shaking table tests,which proves effectivity of the test method.

Abstract: Using one or two electric dipole transmitters in the Controlled source electromgnetic method, this paper calculate the transient electromagnetic responses of one and two 3D conductive anomalous bodies in the layered earth by varying the number and intensity of the dipole sources. The results of the models show that satisfactory resolution can be achieved when only one dipole source is used. The stronger the intensity of the electric dipole source, the better resolution for the anomalous body for the same offset. When two electric dipole transmitters laid each side of one 3D body, it means that the anomalous body locates in the middle of the sources and the resolution to the target becomes poor. The numerical results of the transient electromagnetic responses of two 3D bodies also support the idea that resolution is not good when two transmitters are used in each side of the targets simultaneously. As the conclusion, in order to get good resolution to the target, multi transmitters laid different side of the geological target should not be used the same time in the field survey.

Abstract: Influence of permeated crystalline materials on durability of hydraulic concrete was studied by impermeability test methods after sulfate attack and freeze-thaw cycling. Microstructure of concrete was analyzed and characterized with SEM and MIP. The results showed that impermeability pressure of concrete with permeated crystalline materials was more than that of standard concrete after sulfate attack and freeze-thaw cycling. Permeated crystalline materials improved on performance of concrete for sulfate attack and freeze-thaw, because that microstructure of interfacial transition zone of concrete with permeated crystalline materials was compact and its pore size distribution was more than that of standard concrete. There were more content of less harmful pore with diameter 20nm~100nm and less content of harmful pore with diameter100nm~200nm and more than 200nm in concrete with permeated crystalline materials than in standard concrete.

Abstract: The mineral admixture is one of the indispensable materials for ordinary high-performance concrete. In this paper, the pure cement paste and cement paste replacing by mineral admixture were tested by cement mortar. The SEM analysis of pure cement paste and mineral admixture paste after curing period of 7 days and 28 days.From the picture of SEM after the period of 7 days and 28 days,the cement hydration mechanism was suspected.It could be used for explanating the physical performance and durability performance of the high perfromance concrete with mineral admixture.

Abstract: The static and dynamic properties of the mcrocantilever are presented in this paper, which provides theoretical ways to improve the sensitivity of mcrocantilever. Two methods of resonant excited and detecting mechanism are analyzed with examples. The probabilities of applying these mechanism in gas sensor are also discussed.

Abstract: Abstract: Usually we pay more attention on how to improve gas well cementing quality in engineering design and field operations, and there are so many studies on cement agents but few researches on cement slurry injection technology. The field practice proved that conventional cementing technology can not ensure the cementing quality especially in gas well and some abnormal pressure wells. Most of the study is concentrated on cement agents and some cementing aspects such as wellbore condition, casing centralization etc. All the factors analysis on cementing quality has pointed out that a combination of good agents and suitable measurements can improve cementing quality effectively. The essential factor in cementing is to enhance the displacement efficiency, but normal hole condition and casing centralization are the fundamental for cementing only. Pulsing cementing is the technology that it can improve the displacement efficiency especially in reservoir well interval, also it can shorten the period from initial to ultimate setting time for cement slurry or improve thickening characteristics, and then to inhibit the potential gas or water channeling. Based on systematically research, aiming at improving in 7″ liner cementing, where there are multi gas reservoirs in long interval in SiChuan special gas field, well was completed with upper 7″ liner and down lower 5″ liner, poor cementing bonding before this time. So we stressed on the study of a downhole low frequency self-excited hydraulic oscillation pulsing cementing drillable device and its application, its successful field utilization proved that it is an innovative tool, and it can improve cementing quality obviously.