Advanced Materials Research Vols. 838-841

Abstract: High performance concrete was prepared by using iron tailings mixed with manufactured sand. Effects of the content of iron tailings on the performance of concrete were studied. The results show that the slump of concrete containing iron tailings is equal to concrete with river sand when the content of iron tailings is 60%. With the increase of the content of iron tailings, compressive strength of concrete shows a trend of decrease at same age; meanwhile drying shrinkage decreases and is less than the concrete prepared river sand. After 200 times of freeze-thaw cycle, mass loss of concrete with mixed sand is less than 5% and compressive strength loss is less than 25% which are close to concrete with river sand.

Abstract: In this study, the improved model of CAM with clear parameter was introduced. The visco-elasticity of asphalt mixture under broad temperature and frequency was studied and the properties of asphalt mixture at high asphalt and low temperature of was described by fitting the parameters of CAM model. The four equations of CAM model can be utilized in analysis of visco-elasticity of asphalt mixture and the physical meaning of the parameters in equations was very clear; Through nonlinear curve fitting , the CAM model was found to overcome the defect of deviation from the start and the end fitting; For one kind of asphalt mixture, the complex shear modulus and storage shear modulus was higher in same frequency at lower temperature, and the elasticity was in dominant position significantly; At middle temperature, the modulus of asphalt mixture became smaller; At high temperature, although the modulus was lower, the elasticity was higher. At middle-high temperature, the modulus of asphalt mixture remained smaller and the ratio of elasticity was minimum value, and asphalt mixture was recognized as typical visco-elastic body and was destroyed easily by the deformation disease.

Abstract: In this paper, through the study on physicochemical properties of chloroprene rubber which used in immersed tube tunnel, and comprehensive analysis of the stress relaxation process of aging, together with the analysis of IR spectra of chloroprene rubber, and the accelerated aging test data, we forecast the lifetime by using WLF equation method at the room temperature, and judge that chloroprene rubber can meet with the requirements of the design life of 120 years.

Abstract: A non-smooth surface with convex domes was fabricated on a chemical polished 2024 aluminum alloy substrate using the method of pressing with a symmetrically distributed concave hole module. Anode oxidation technique was used to prepare alumina films on a non-smooth surface. The as-prepared surfaces possessing microscale morphology and multiscale structures without anything chemical modification exhibited excellent hydrophobicity, and had a maximum water contact angle of about 133^o. The microscale morphology of the non-smooth alumina films were investigated by a stereo microscope and a laser scanning confocal microscopy. A scanning electron microscopy was used for surface corresponding microstructure of the non-smooth alumina films. The forming course of the alumina films with pores was analyzed. Such an alumina films that combine excellent hydrophobicity with other properties may have many potential applications.

Abstract: The effect on concrete strength of various kinds factor was systematically studied by orthogonal test. The amount of cementitious material, slag content, silicon content, water cement ratio, aggregate gradation and other factors was consider. By adjusting the parameters of the experiment, the C100 concrete was preparation successfully, which has high stregth and pumping perfomance. The interface structure of the C100 concrete was analyzed by scanning electron microscope (SEM) and found that C100 has a better interface structures. The concrete is a system and his strength depends on the strength of the suitability of various materials, which is a new point of view was put forward.

Abstract: One of the main objectives of this study was to activate the pozzolanic activity of sludge, produced by municipal sewage treatment plants (MSTP), which makes it become an admixture to replace a part of cement in cement-based materials. Nowadays, a significant quantity of MSTP sludge is obtained in China, and the disposal of sludge presents a rising challenge for the environment, which is the reason why this paper examines the possibility of adding this waste product to cement-based materials. MSTP sludge was activated by thermal (Incineration) and mechanical (Grinding) treatment. Meanwhile, the changes in the crystalline structure of MSTP sludge incineration ash (MSA) were evaluated using X-Ray Diffraction (XRD), and mortar strength tests were carried out on the mortars containing MSA to investigate the reactivity of the produced materials. The obtained results revealed that the optimal activation conditions of MSA were as follows: incinerated at 800°C for 2.5 hours followed by fast cooling in air and then ground until 60 minutes. Moreover, we have observed that MSA has an appreciable effect on the increase in compressive strength of the mortars and using of 20% MSA as a replacement of part of cement could be considered the optimum content. More importantly, the tests showed that extract toxicity of heavy metals in MSA were much lower than the national standard though some heavy metals existed in MSA. These results demonstrate the feasibility of recycling MSTP sludge has become an admixture in cement-based materials for construction engineering.

Abstract: A new thermal insulating material was developed on the basis of a geocement, formulated as Na₂OAl₂O₃6SiO₂20H₂O. Ground limestone and aluminosilicate pellets were used as fillers for its production (composition: geocement 64.29 wt. [%]; fillers 35.71 wt. [%]). This material, which is applied having a thickness of 3.0-4.5 mm, swells when it is exposed to an external heat flow of 1273 K average temperature. Swelling is due to the matrix phases and filler dehydration, which include heulandite, ussingite, sodium zeolite and other phases. As a result, a finely porous glassy aluminosilicate frame of jadeite-albite composition is formed, which is characterized by low thermal conductivity (0.09-0.175 Wm^-1K^-1). The developed material can be used to protect and to insulate wooden, metal and concrete surfaces from an one-sided heat source. The paper is dedicated to the great scientist of the XXI century in the field of alkali-activated cements and materials based on them, Pavlo Kryvenko, in honor of his 75^th birthday anniversary.

Abstract: Using the experimental method with different spacing interval determined the degree of the target to the jet penetration ability. In order to verify the effect of interval size on the jet penetration, sunder armor ammunition simulation experiment was carried out, using a 40-mm sunder armor ammunition penetrated designed target plate. Through the study of residual penetration data, verify and sort out the regulations of the jet penetration. The experimental results show that the interval of the target of jet penetration has more adverse effect, at the same time also can reduce the diameter of the jet hole, the jet attenuation effect is obvious.

Abstract: 1,3,4-oxadiazole (OXD) and its derivatives have excellent thermal stability and oxidation resistance and strong blue fluorescence emission [.Six novel compounds have been designed and synthesized And their structures were confirmed by ¹HNMR,FT-IR,MS, UV-vis absorption results showed that the maximum absorption wavelength appeared at 430nm,and fluorescence spectroscopy results showed that emit strong purple fluorescence in DMF solution.

Abstract: The operational stability of mineral wool materials is largely determined by the uniformity of polycondensation the binder in the material volume. For optimization the thermal treatment parameters software system was designed, and its been tested in technology of layered products.