Applied Mechanics and Materials Vols. 71-78

Abstract: Asphalt aging is inevitable to the asphalt pavement performance, which will lead asphalt to hardening gradually and becoming brittle. Therefore, aging progress shortens the life of asphalt, but the study on polymer asphalt improves the phenomenon. The present situation on aging of polymer modified asphalt is summarized and the aging mechanism of modified asphalts is analyzed in the paper. Otherwise, the research progress at home and abroad on the aging properties of modified asphalt is introduced by a series of characterization techniques, which include mechanics technique, rheology technique, FTIR, GPC and so on

Abstract: Due to the rough surface of the recycled concrete aggregates, low modulus of elasticity and large porosity, these properties led to that the apparent density, strength, physical properties and durability of the recycled concrete made by recycled aggregates are different from the Portland cement concrete, so that the standards and requirements formed about the Portland cement concrete are not entirely suitable for the recycled concrete. On the basis of the experimental studies, this paper analyzes the differences of mass loss, crushing strength and neutralization depth between the ordinary Portland concrete and recycled concrete under the influence of simulation acid rain. The results showed that there are different degrees of change between the concrete with 100% aggregates instead of recycled aggregates and the Portland concrete in mass loss, crushing strength and neutralization depth under the influence of simulation acid rain.

Abstract: With the rapid development of urban construction, the waste that construction brings is also increasing. The recycled concrete technology can solve the problems of waste concrete, but also save the natural sand. This paper gives the progress on the research about the reliability of recycled concrete. Because of the rough surface of the recycled concrete aggregates and large porosity, the apparent density, strength and durability of the recycled concrete are different from the ordinary concrete on many aspects. So the study of the reliability about the recycled concrete is very necessary. The page will research on the material subentry coefficient of fifty and sixty years.

Abstract: Due to its ability of photocatalysis and photoinduced superhydrophilicity, TiO₂ was paid significant attentions in recent years. In this study, TiO₂ films were deposited at room temperature and 300 °C by pulsed dc reactive magnetron sputtering. The gas pressure was varied in the range of 0.3-1.1 Pa by filling Ar/N₂ gas mixture with the ratio of 1:1. The surface morphologies, phase structure and optical property of the TiO₂ films were investigated. TiO₂ films with good crystalline quality containing mainly of anatase phase were obtained by deposition using gas pressure of 0.7 Pa at room temperature and gas pressure of 1.5 Pa at 300 °C.

Abstract: Mg-Al spinel has been synthesized by using alkali corrosion slag from aluminum profile factory, decomposed magnesite and used MgO-C brick as the main raw materials. The influence of decomposed magnesite and used MgO-C brick powder after calcinations process on crystalline constitution and micro-morphology of synthesized Mg-Al spinel specimens are discussed. The synthesized specimens are characterized by XRD and SEM, and the crystallinity of crystalline phase is calculated by X' Pert plus software. The experimental result shows that the crystalline phase periclase increases with the increasing of magnesia generated by used MgO-C brick powder. The crystallinity of crystalline phase is maximum when the addition of used MgO-C brick powder after calcined at 800°C is 30wt%. Magnesia generated by sintering decomposed magnesite powder at 700°C showed more effective than magnesia generated by used MgO-C brick powder to react with impurity in alkaline corrosion slag.

Abstract: In this paper, the research on the catalyst sulfur poisoning in recent years were reviewed, including the reason and mechanism of sulfur poisoning, dynamics for deactivation, recovery and regeneration of catalyst.

Abstract: According to the research of geology condition in Ge-he-yan's back rock mass slope,set up the homologous engineering geology model, carried on parts of qualitative analysises, combined with numerical analysis method based on the unloading rock mass theory, gave the quantitative analysis of the engineering geology model, then got the special deformation mechanism of this slope.

Abstract: Characteristics of vibration molten metal droplets are decisive importance to performance of high velocity arc sprayed coating, it is hardly that detected the dynamic action of liquid droplets owing to the limitation of experimental technique. The gas fluid-liquid droplet coupling vibration system of equations were established based on wave-like disturbance, the governing equation for fastest-growing wave number is derived. The agreement of predicted fastest-growing wave number and data of Bradley, which has the deviation within the±2% limits,indicares that the gas fluid-liquid droplet coupling vibration system of equations is effective. By the use of the coupling vibration system of equations, the effects of gas velocity, gas type and molten metal type to vibration characteristics of HVAS droplets is researched. The results show that selected N₂ gas sprayed and increasing the gas velocity would be raise adhesive strength of the spraying coating, and provides theoretical evidence for choice of spraying materials and control in HVAS.

Abstract: The rationality of spatial environment design and operational parts’ layout design in ATC (All Terrain Crane) cab needs to provide a quantitative basis through objective evaluation and analysis. In this paper, 3-D space model of ATC cab is constructed in accordance with data provided by a new type of ATC in a famous domestic crane enterprise, and the Chinese human database is established based on Human Dimensions of Chinese Adults(GB10000-88). Besides, the interior design ergonomic evaluation system of ATC cab is created by customizing specific toolbars and dialog boxes with VB language secondary development on CATIA software platform. This system can evaluate comfortable areas and reaching scopes of joystick, seat, pedal, steering wheel and other operating devices and give the evaluation conclusions. This provides a feasible and effective design evaluation method for computer-aided interior design of ATC cab.

Abstract: To study further mechanical behavior of flexural members of carbon fiber reinforced concrete, this text uses the methods of fiber materials composite principles and balance equations, and derives the elastic modulus of the carbon fiber concrete. The acting principle of carbon fiber in the concrete is analyzed. Based on three bearing stages of carbon fiber reinforced concrete beam, the calculation formulas to flexural bearing capacity of carbon fiber reinforced concrete are given. It is theoretical basis of implication of carbon fibers in civil engineering.