Advanced Materials Research Vol. 742

Abstract: This article through the test of impacts on mortar strength when limestone concrete recyclable micropowder replacing the cement in low volume, and analyze the phase of fired cement, then discussed the use of renewable cement. The test results showed that, with the new ground renewable micropowder replacing mortar cement, mortar strength did not decrease, but also increased, at the same time, renewable micropowder contains large numbers of CaCO3, which can be used as the raw materials of cement baking calcareous. However, the phase analysis of burning cement clinker XRD showed that the main mineral component of silicate cement clinker, which offering the feasibility strong support on cement production for the renewable micropowder.

Abstract: The paper is on the basis of the study on mechanism of Soil solidifying agent,and created a New JJH Soil solidifying agent compounded of NaOH and slag micropowder which are the main raw material,then studied its properties. The results show that the unconfined compressive strength, water stability and freeze thaw stability of the new soil solidified agent are performance. It can meet the requirements in relevant national technical specification, the 7d age strength of solidified soil is more than 2MPa and water stability coefficient is more than 0.8. opens up a new train of thought to a new type of soil solidifying agent.

Abstract: The Cu₅₀Zr₄₂Al₈ dumbbell-shaped alloy with original scale distance of 25 mm and diameters of 4.5 mm was prepared by the suspend melting-copper mould suction casting. The structure tensile performance testing and the fracture morphology observation of Cu₅₀Z_r42Al₈ BMG as-quenched and 400k/1h isothermal annealing were investigated, respectively. The deformation and fracture behavior of samples had been studied. The results showed that the structure of all samples were composed of amorphous phase and possess good glass formation abilitysample as-quenched is always in the elastic deformation stage during elongation and the tensile strength is 629MPa; however ,for specimen after 400k/1h isothermal annealing ,the yield phenomenon occurs before breaking and the maximum tensile strength is 755Mpa, and the same time, the maximum failure extensibility increases from 0.56% for sample as-quenched to 0.80% for 400k/1h isothermal annealing. The fracture pattern of test sample at annealing assumes venation pattern, which is similar to fractography of Cu₅₀Zr₄₂Al₈ BMG as-quenched, in addition, which appeared apparent viscous flow behavior and melting characteristics.

Abstract: Results of experiments, focused on development of modified AZ61 alloy structure after hot forming, are summarized in this paper. Microstructure changes of the alloy after rolling and forging at temperatures of 380°C and after ECAP processed at 250°C were observed. After forging, the original grain size was reduced almost 14 times down to a value around 9 μm. After ECAP the grain size reduction was even better, almost 60 times. Important role of the ß-phase (Mg₁₇Al₁₂) in this alloy, during plastic forming, was confirmed. Independently of processing technology, the best final properties of the AZ61 alloy were supported with very fine particles distributed in the Mg matrix. The experiment succeeded in proving the influence of precipitates on restoration processes too.

Abstract: The cement paste forms the basis of a concrete composite. This article is focused on the analysis of the creep of cement paste with fly ash based on experimental measurements. Measurement results of creep-dried and water saturated pastes are presented. The ratio of cement to fly ash of 1:1 was used for the production of the mixture. Experimental measurements were carried out on material age of 4 months.

Abstract: Paper describes properties of cement paste included addition of the fly ash. Firstly is described the preparation of the cement paste. Next part is focused on the testing of the properties. Results of the testing are summarized in properties like a compression strength, Modulus of elasticity and strength in bending. Finally the relation between material properties and volume weight is discussed. An article is described paste made from the same amount of cement and fly ash and water coefficient of 0.4.

Abstract: In this study, ethylated wood powder/polystyrene plastic composite (WPC) was obtained by combining ethylated Chinese Fir powder with polystyrene foam in DMF or CHCl₃, and was dyed with disperse dyes. The results show that the compatibility of ethylated fir powder with polystyrene was good when the ratio of wood to plastic ratio is beyond 3:1. The color shade of dyed wood-plastic powder is close to that of dyed polyester fabric and high temperature is favorable for the dyeing of wood-plastic powder. Moreover, dyed wood plastic powder has good washing fastness, which depends on the molecular structure of disperse dyes, dye concentration and dyeing temperature.

Abstract: The paper introduces the experiments of sulfate attack on concrete under stress state. The concrete (MSFAC) was made with machine-made sand and fly ash. Before immersed in sodium solution with sulfate-ion concentration of 50000mg/L, the concrete beams with 100mm×100mm ×400mm dimension were in flexural tensile stress at levels of 20%, 40% and 60% of flexural tensile strength by the special designed stress devices. The sulfate-ion content in different erosion depths of concrete was measured at attack age of 30, 90, 180, 270, 360, 540 and 720 days by the chemical titration method. The results show that the apparent damage such as rough surface and cement past peeling off became more serious with the increasing tensile stress level and the prolongation of attack age, while much more obvious crystallization of gypsum was in surface cracks, the sulfate-ion content in the first layer near surface did not reflect the real status of concrete affected by tensile stress levels. The sulfate-ion contents of inside layers increased basically with the attack age at stress levels lower than 60% of tensile strength of concrete. In conditions of the experiment, the sulfate-ion content reduced when the attack age was longer than 540 days at the stress level of 60%.

Abstract: The derivatives of HNS are optimized to obtain their molecular geometries and electronic structures at the DFT-B3LYP/ 6-31G^* level. Their IR spectra are obtained and assigned by vibrational analysis. Compared with the experimental results, all the calculated IR data are found to be reliable. Based on the frequencies scaled by 0.96 and the principle of statistic thermodynamics, the thermodynamic properties are evaluated, which are respectively linearly related with the number of methyl, azido and difluoramino groups as well as the temperature, obviously showing good group additivity.

Abstract: A method of analysis and optimization of stepped plates made of elastic plastic materials is developed. The stress-strain of the plate is defined for the initial elastic and subsequent elastic plastic stages of deformation. Necessary optimality conditions are derived with the aid of variational methods of the theory of optimal control. This results in a differential-algebraic system of equations. The latter is solved numerically. The effectivity of the design established is assessed in the cases of one-and multi-stepped plates assuming the material obeys the Tsai-Wu or von Mises yield condition.