Applied Mechanics and Materials Vols. 174-177

Abstract: In order to apply manufactured sand in the field of concrete engineering, the workability of concrete influenced by manufactured sand grading is studied. The test shows that whereas the grading of sand satisfy the code sand grading standard regions, the workability of concrete with them are significantly different. The grading with stretch shapes “S” form is much better than that with stretching like opposite “S” form or parabola.

Abstract: To find out the characteristics, color’s genesis and identifying features of TCF (Thermal Color Fusion) topaz, and the differences between TCF topaz and the past coating topaz products, this article takes TCF topaz, which appeared recently in the market, and two other common generation of coatings topaz sample as the object of study, and use a variety of gemology testing instruments and wide spectrum and narrow spectrum of X-ray photoelectron spectroscopy to analyze the gemology feature, surface structure and composition of the sample, the results shows that: the difference of the surface layer composition is the basic reason for the color difference of these samples, but the film structure and thickness of the sample do not have a big impact to the color. This article has also carried on the examination to the sample durability, at the same time analyzing and comparing a variety of optimized topaz production process. The TCF topaz technology has the advantages of both two kinds of process of coating and the diffusion, TCF topaz is rich in color compared to diffusion and irradiation product, it is better than irradiation product on high temperature resistance and radioactive residues.

Abstract: Pulse shape motions and huge amount of energy applied in short duration by the near fault earthquake, cause brittle fracture in welded connections, which is widely observed in Kobe 1995 and Northridge 1994 earthquakes. Rigid connections, which are generally welded due to lack of ductility, have low energy absorption capability. On the other hand, Semi-rigid connections have a ductile behavior and have a good ability to absorb energy. The purpose of this paper is analysis and compares the behaviors of “rigid” and “EEP semi-rigid” connections in cases of “four bolt extended”, “eight bolt extended stiffened” and “eight bolt, four bolts wide, extended stiffened” under the near fault earthquakes with nonlinear time history analysis by perform 3D software. The results shown that the steel frame with “four bolt extended” semi-rigid connections have appropriate performance compared to the other frames.

Abstract: In order to study dynamic mechanical properties of concrete, the impact compression tests of concrete material under three different velocities are conducted using a light gas gun. Flyer and target are made of the same material, the manganin pressure gauge is used to measure the time-pressure curves of the samples. The measured time-pressure curves show that the stress peak will increase with the increase of flyer speed, and the stress peak at different locations will decrease with the increase of dissemination distance. It illustrate that concrete material has obvious rate sensitivity and energy dissipation characteristics. Then, through further analysis of the experimental data, the shock hugoniot relationship is determined, that is a linear relationship between the shock wave speed and the wave particle velocity. Based on the shock hugoniot data of the concrete, the high-pressure polynomial equation of state is fitted.

Abstract: By using finite element method, the thermal stress of stress absorption interlayer of asphalt overlay on the cement concrete pavement is analyzed in this paper. The result shows that the inter-laminar shear stress and the structural vertical displacement are influenced by the thickness of stress absorption layer, while the asphalt bottom stress is less affected; the increase of the modulus is unfavorable to the structural vertical displacement, the inter-laminar shear stress and the asphalt bottom stress.

Abstract: Through the pull-out tests of the following three pavement sealing techniques: rubber asphalt, SBS modified asphalt and SBR modified emulsified asphalt, a contrast was made to analyze the influence of temperature on the pull-out strength and the displacement value of damaged sealing coats, so as to analyze the temperature sensitivity of the three sealing coats of synchronous pavements. The results show that: the rubber asphalt sealing coat, modified by the rubber power, has good temperature sensitivity and the temperature susceptibility of asphalt has been improved, with a greater ductility in low temperature and a better resistance to flow deformation in high temperature.

Abstract: Fixed the composition of matrix slurry in low cement castable, added different additives such as STPP, KS-JS70, GLENIUX, Rheoplus, LMS-P, determined the slurry viscosity by using the NXS-11A rotary viscometer, analysised the rheological properties of the different matrix paste.Studies have shown that: there is a certain influence on the slurry rheology for different species and dosage, and there is the appropriate dosage. Analyzed the mechanisms of different admixtures on the rheological properties of slurry on theoretical.

Abstract: With printed silver electrode and etched indium tin oxide (ITO) stripe, the double cathode-conducting-layer was developed on the cathode back plane. The lower ITO electrodes were composed of divided ITO film covered on the cathode back plane and the upper silver electrode was formed by the sintered silver slurry. And the cathode insulation layer was used to separate the lower ITO electrodes and the upper silver electrodes. Carbon nanotube used as field emitters, the fabrication research on the field emission display panel was performed. The main function for the double cathode-conducting-layer was to decrease the cathode voltage drop on the upper silver electrodes on the cathode back plane. The sealed small size field emission display panel possessed better image display performance.

Abstract: The organization of nanostructures across extended length scales is a key challenge in the design of integrated materials with advanced functions. PbZr_0.52Ti_0.48O₃ multilayer disks which were constructed by oriented rectangle nanoparticles were easily prepared by a simple surfactant-free hydrothermal process. The as-prepared powders were characterized by X-ray powder diffraction (XRD) and scanning electron microscopy (SEM). The results indicated that the as-prepared PZT disks were constructed by self-assembly of rectangle nanoparticles by a perfect manner. The formation mechanism of the products was discussed.

Abstract: Ceramic oxide coatings were produced on pure titanium by plasma electrolytic oxidation in different electrolytes. The variation of coating thickness with applied voltages revealed coating almost kept a steady-state growth rate in electrolyte A and B, but not for electrolyte C. Numerous nodules occurred on the surface of the coatings at 200V in electrolyte A and B, and then nodules disappeared with the applied voltage increasing to 300V. There was no nodules occurred, and pore size was evidently different in electrolyte C. When the applied voltage was 300V, the coating formed in electrolyte C exhibited the highest corrosion potential and lowest corrosion current density in 3.5% NaCl aqueous solution.