Advanced Materials Research Vols. 168-170

Abstract: Biodiesel was synthesized using waste chicken oil and ethyl alcohol as reactives as well as denatonium benzoate and tin particles as catalysts in 500 mL three neck flask. The reaction mixtures were mechanically stirred at 200 rpm during 15 minutes at 30, 40, 50, y 60 º C, after that the products were filtered trough a 400 m mesh an then casted in a separating funnel in order to obtain two layers corresponding to glycerol and Biodiesel. The tin catalyst particles were observed by optical microscopy. The biodiesel and glycerol were characterized using refractive index, pH, Fourier transformer infrared spectrometry (FTIR), while the viscosity was determined in a Brookfield viscosimeter and density using a picnometer. The results suggest that at a low concentration of denatonuim benzoate (7 ppm) the reaction will occur only if tin is present at all test temperatures. The pH of biodiesel obtained was 6, similar to petrodiesel used commonly in diesel motors.

Abstract: This paper describes five push-out tests carried out at the University of Malaya using channel shear connector. The tests study experimentally and analytically, the behavior of channel shear connectors embedded in normal and light weight aggregate concrete (LWAC). Limited push-out tests are used to measure the accuracy of a proposed nonlinear finite element model for typical push-out test specimens. Using this model, an extensive parametric study performed to arrive at prediction for shear capacity of channel connectors in LWAC. An equation is suggested for the shear capacity of these connectors in LWAC.

Abstract: The performance of resisting foundation displacement of a typical single return circuit transmission tower under all kinds of load conditions including foundation horizontal displacement, foundation vertical uneven downward displacement was analyzed by finite element modeling. Results showed that stability failure of single steel angle represents tower’s limit state under foundation displacement. And the corresponding foundation displacement limits were calculated. Results indicate that foundation pull condition is more dangerous than press condition. Under complex foundation displacement conditions, foundation horizontal displacement is primary factor leading to stability failure of towers. Under foundation press condition and pull condition, wind load is primary factor. Result also indicates that, tower does not fail when foundation displacements are smaller than 1.25% (under foundation press condition and pull condition) or 0.5% (under single foundation sink condition) of tower root distance.

Abstract: Resin transfer molding (RTM) is a very important category of low cost fibre reinforcement composite material manufacturing technique. But void which mainly formed at the process of filling and infiltration is able to reduce the performance of products. This paper first introduced how harmful the void is, and then formation theory, finally focus on the technical feature and resent evolution. Numerical simulation is always a mature and efficient research method for this field of investigation. Formerly, scientists also attribute their effort to such investigation, but, at that time, their simulation was 1D or 2D which can not represent the process accurately enough. Therefore the results are not so significant. Recently most studies pay attention to 3D simulation and how factors (such as injection pressure, structure of preform and so on) work. With the development of mathematic theory and simulation software some new numerical simulation methods present itself. Researchers may copy the course of resin’s filling in RTM more integrity to make their relation close to reality. Based on their achievement, the technique of RTM also improved to eliminate void’s emergence. However the real flow of resin is more than complex, more work should be done to avoid it and then set up a controllable industrial production system.

Abstract: Aimed at problems lying in the exiting methods for calculation of laterally loaded piles installed in layered soils, the elasto-plasticity solution of cast-in-place concrete pipe pile with large diameter (PCC pile) in layered soil under lateral load based two-parameter foundation model and unity limiting force profile, deduced the finite difference solution based unity limiting force profile(LFP), established the calculation program of the displacement and internal force of pile. It was shown that the calculated pile moment and pile displacement coincided very well by computation and comparison of model test and FEM, verified the method’s correction. Meanwhile, the method was more precise and efficient than the existing conversion methods of subgrade modulus. Therefore, it could be useful for the design and analysis of PCC pile under lateral load.

Abstract: Recent studies show that a through beam connections composed of concrete filled square steel tubular column and steel beam have been identified as an ideal rigid connection. In this paper a 3-D nonlinear finite element models were conducted for CFSST column and steel beam connection under monotonic load using ABAQUS software. Each model includes a CFSST column and single steel beam passing through the column. The main scopes are to identify the modes of beam failure and joint shear failure. In addition the effect of an extra shear plate welded to beam web inside the column was investigated. This result can be used for designing of through beam connection.

Abstract: Replaced backfilling clay is one of the treatment measures in the Luwangfen swelling rock test Region of middle-route of South-to-North Water Division Project. First, by using 18 tons vibration roller compaction mechanism, on the condition of 3 different thicknesss and 5 different compaction times, settlement, dry density, water content and permeability coefficient are studied before and after the compaction test to find out the optimal thickness and compaction times. Then, by using different compaction mechanisms, the compaction effect is studied on the condition of the optimal thickness and compaction times. Results show that the compaction degree of replaced backfilling clay is 100.0% on the condition that the quantity of vibration bumping roller is above 18 tons, thickness of replaced backfilling clay is no more than 35.0cm and at least it is compacted at least 12 times. Finally, the construction parameters of compaction and related quality controlling index is proposed, which is provided as a reference for design, mechanism’s choice, compaction parameter and quality control index.

Abstract: This project studies the alternative chemical recycling of disposable bottles as raw material for the manufacture of a product known as polymeric concrete, which has several applications in the construction industry. Crosslinked materials from polyethylene terephthalate (PET), glycerol and clay were obtained. First recycled PET bottles were washed, cut and dried; after bis-hydroxyethyl terephthalate monomer was obtained from depolimerization reaction of PET. The monomer, glycerol and titanium dioxide reacts to synthesize a polymeric concrete. Materials with concentrations of clay from 1, 10, 20, 30, 40 and 50%w/w were obtained. Differential scanning calorimeter (DSC), Soxhlet extraction, colorimetry and Shore D hardness were used to characterize the materials. The results indicated a degree of crosslinking in the synthesized material when the amount of clay was increased. A melting point around 265 °C was not observed by DSC analysis; this suggests that a crosslinked material was formed. By TGA analysis temperature degradation was observed at 394°C, which it was increasing from 408 to 416°C according to the addition of clay content. A bad dispersion of particles in the crosslinked polymer decreased the thermal stability of PET when the clay content was increased.

Abstract: Post-embed pullout tests are applied to the concrete cubes of C15-C60. Based on the result of 50 concrete samples, the relationship between pull-out resistance and compressive strength of concrete has been discussed in detail, and the formula used for calculating the concrete strength is given out. Its related coefficients and relative standard can meet the requirement. The simulation method is used on the base of curving failure surface. The paper presents the destruction mechanism of pull-out method in concrete property test, and good correlation between the date of pullout force and cube strength is explained.

Abstract: Indium stannate (InSnO3) films doping with small amounts of copper are made highly useful as architectural window coatings. Indium-tin-oxide (ITO) has attracted intense interest due to some of its unique characteristics; it has high optical transmittance in the visible region, low electric resistivity, and chemical stability. Therefore, ITO thin films have been found to play an important role in opto-electronic applications. In this work, uniform and transparent ITO films were deposited onto glass substrates using a sol-gel process. The initial sols were prepared by mixing solutions of indium chloride prepared in anhydrous ethanol with tin chloride and mechanically stirring and refluxed 2 hours and aged 2 week, the resultant mixture until a clear and sticky coating sol was obtained. The glass substrates were spin-coated and annealed at 500 °C. Because annealing conditions affect the microstructures, the properties of the resultant ITO films can be controlled. The optical transmittance of 200 nm thick ITO film was more than 80% in the visible region. The surface morphology examined by SEM appears to be uniform over large surface areas. The structural, microstructural and optical properties of the coatings and powders made from the sols were extensively characterized by using XRD, AFM and spectrophotometer techniques