Advanced Materials Research Vols. 150-151

Abstract: The sol-gel method was employed to prepare the Eu3+-doped TiO2 thin films. The influence of doping concentration and annealing temperature on the structures and photoluminescence (PL) properties was investigated. The result of X-ray diffraction revealed that all the films are of anatase phase. It is shown that the PL intensities of the films increased with Eu3+ concentration and reached the maximum at 1.4 mol%, then decreased with the concentration. Observed anatase phase appeared at temperature above 400 °C, and the luminescence intensity increased with the increase of annealing temperature.

Abstract: Four kinds of industrial solid waste, granulated blast furnace slag (GBFS), electric furnace steel slag (EFSS), semi-dry flue gas desulfurization slag (FGDS) and gypsum were activated by mechanochemistry to prepare a novel kind of cementious material, DA type soil solidification agent (DA agent). Compared to the traditional cementious materials, this paper evaluated DA agent used in silt soil solidification project. Test results showed that DA-4 was prepared with adding the 40% CFBA, 39% GBFS, 11% OPC clinker and 10% gypsum by mill and more superior in material characteristics. It was found that compressive strength of DA-4 paste and mortar specimens at 28-days cured age were 46.0 and 27.3 MPa respectively; 5% of DA-4 was used to stabilize the silt soil in lab and the maximum dry unit weight, optimum moisture content, unconfined compressive strength and CBR value were 1.754 g/cm3, 15.35%, 1.15 MPa and 95.5% respectively. The hardening mechanism of prepared cementious materials is explained by two points: the sulfite or sulfate activation on alkali blast furnace slag; and the hydration product produced from cement clinker hydration process. Besides test programs of the trial pavement section in site showed that stabilized and solidified silt soils by DA-4 can meet the requirement of subgrade of pavement for strength and stiffness.

Abstract: Seismic damage, such as falling, fissure and dislocation of the lining may happen at location of fault movement. The model of enhancing stiffness and that of adding seismic decrease layer are built by the finite element software MIDAS to compare the two earthquake-resistant methods. Some useful results are obtained: a)The displacement is decreased, but the peak acceleration and first principle stress of the lining are increased in the model of enhancing the lining materials stiffness. b) The displacement, peak acceleration and first principle stress are all decreased in the model of adding seismic decrease layer. c) The max-displacement when using c20 as lining material or adding seismic decrease layer is in the area of fault, but that of the model when using c40 as lining material is in the area of entrance.

Abstract: The application of phase change materials (PCMs) is very promising in buildings because it allows the storage and discharge of considerable quantities of cooling and heating energy, dumping the air temperature swings within the building so that the indoor air temperature is closer to the desired temperature for a longer period of time. In order to account for the good characteristics of Alumina nanoparticle-in-paraffin as phase change material, based on enthalpy-porosity model and numerical analysis, detailed phase fields and heat flux are obtained, compared with that of pure paraffin. And study demonstrates that room with ENPCM ceiling is a good way of saving cool energy in summer.

Abstract: Liquid crystal polyurethane (LCPBI) containing biphenylnate and imide units was synthesized and characterized and used to modify the conventional epoxy resin (E-51). Experimental results revealed that the impact strength of the epoxy resin modified with LCPBI was 2.5 times higher than that of unmodified epoxy resin, and the tensile strength as well as the bending strength was also improved. The thermal decomposition temperature of modified systems was also 15-20oC higher than that of the unmodified system, and the fracture structures of the blends was investigated by SEM.

Abstract: Basalt fiber and carbon fiber hybrid with alternate stacking sequences reinforced epoxy composites have been developed to improve the toughness properties of conventional carbon fiber reinforced composite materials. For comparison, plain carbon fiber laminate composite and plain basalt fiber laminate composite have also been fabricated. The toughness properties of each laminate have been studied by an open hole compression test. The experimental results confirm that hybrid composites containing basalt fibers display 46% higher open hole compression strength than that of plain carbon fiber composites. It is indicated that the hybrid composite laminates are less sensitive to open hole compared with plain carbon fiber composite laminate and high toughness properties can be prepared by fibers' hybrid.

Abstract: Based on effective composite material failure criteria and property limited degradation model, axial compressive ultimate strength of composite laminated stiffened panels are analyzed by nonlinear laminated degenerated 3D finite element analysis, which is based on incremental continuum-based updated Lagrangian formulation. Comparison between analytical solutions and test results in this article indicates that this article provides an effective and practical method to evaluate the axial compressive ultimate strength of composite laminated stiffened panels. Using this method, ultimate strength of hull girders made of continuous basalt fiber composite materials are analyzed . Comparing the results，it can be seen that the ship hull in basalt fiber composite materials has equivalent longitudinal ultimate strength to S-2 glass fiber composite materials, basalt fiber composite material could replace the S-2 glass fiber composite materials used in shipbuilding engineering. The gist for building ship with basalt fiber composite materials was provided by this paper.

Abstract: Several different sintering systems about the formation of C3A ,by mixing CaO and Al2O3 powder, are studied in this experiment. The sample is characterized by glycerol ethanol method, X-ray powder diffraction and TG-DTA. The experimental results show that: reducing the react time cannot boost the formation of C3A, but traditionally electrical heating combined microwave heating can romote the formation of C3A rapidly .In terms of phase equilibria of CaO-Al2O3 system, pure C3A cann’t be synthesized by sintering . Except the samples also contain minor amounts of CA and C12A7.

Abstract: The core-shell acrylic emulsion was synthesized，with P(MMA/BA) as core，and with P(2-EHA/MBA/HPA) as shell. The influence of the mass ratio of core/shell on mechanical properties was investigated in detail. The high elongation at break proved that the emulsion may have a potential application in coating industry, afforded by HPA as functional monomer. However, when the amount of HPA exceeds 1.5 wt. % to the total monomers, the emulsion will become unstable and precipitation occurs.

Abstract: The concrete cutoff wall is a technology used in reinforcing sick dams more usually in recent years. In the text, the advanced FLAC3D method which is based on 3-D explicit finite difference method, is used to simulate a reinforcement of earth dam using concrete cutoff wall. Through the simulation, Mohr-Coulomb model, elastic model and Goodman element are used to analyse the distribution of the stress and the strain of the dam before and after reinforcement. Consequently, we can evaluate the unti-seepaging effect and raise the possible question.