http://www.hindawi.com The latest articles from Hindawi Publishing Corporation © 2013 , Hindawi Publishing Corporation . All rights reserved. Thu, 23 May 2013 19:15:10 +0000 http://www.hindawi.com/journals/amse/2013/790321/ Three primary pigment/poly(n-butyl acrylate-co-styrene) (P(BA+St)) nanocomposites were prepared via encapsulation of the corresponding organic pigments via the miniemulsion technique. The resulting latexes of the P(BA+St)/pigment nanocomposites were filmed in a PTFE mould or printed onto cotton fabric. The morphology of the P(BA+St)/pigment nanocomposites and the dispersion of pigment particles in the latex film and on the printed fabric surface, as well as the adhesion between pigment and adhesive film, were evaluated by transmission electron microscopy (TEM), field emission scanning electron microscopy (FESEM), 3D digital microscope system (3D-POM), and printing results tests. Attributing to the preprotection of adhesive polymer shell, the self-adhesive P(BA+St)/pigment nanocomposites were homogeneously and firmly dispersed both in the thin latex film and in the adhesive layer on the fiber surface. As a result, the color strength, color fastness, and handle of the fabrics printed by the P(BA+St)/pigment nanocomposites latex were significantly improved, compared to the fabrics printed by the conventional pigment blended latex. Dongming Qi, Zhijie Chen, Lei Yang, Zhihai Cao, and Minghua Wu Copyright © 2013 Dongming Qi et al. All rights reserved. Thu, 23 May 2013 19:09:28 +0000 http://www.hindawi.com/journals/amse/2013/918294/ The paste/mortar attached to the recycled aggregate decreases the quality of the aggregate and needs to be stripped. The stripped paste/mortar is roughly 20% to 50% in waste concrete, but relevant research is very limited. In this paper, the effects of ground waste concrete (GWC) powder, coming from the attached paste/mortar, on water demand for normal consistency, setting time, fluidity, and compressive strength of cement were analyzed. The results show that the 20% of GWC powder (by the mass of binder) has little effect on the above properties and can prepare C20 concrete; when the sand made by waste red clay brick (WRB) replaces 20% of river sand, the strength of the concrete is increased by 17% compared with that without WRB sand. Xianwei Ma and Zhenyu Wang Copyright © 2013 Xianwei Ma and Zhenyu Wang. All rights reserved. Wed, 22 May 2013 13:02:40 +0000 http://www.hindawi.com/journals/amse/2013/436946/ The purpose of this study is the improvement of the behaviors of walls constructed with masonry bricks using reinforced plaster mortars. In this study,  mm sized walls were constructed using 1 : 2 scaled  mm sized masonry bricks. The walls were plastered using normal and various proportions of polypropylene and steel fiber reinforced plaster mortars and were subjected to vertical loads at 30°, 45°, 60°, and 90° angles. As a result of the experiments, attempts were made to present the strength, stiffness, and ductility of all of the walls. At the end of the study, an evaluation concerning failure envelope curve (-) obtained from test results according to plastered masonry walls types was performed. Hakan Basaran, Ali Demir, and Muhiddin Bagci Copyright © 2013 Hakan Basaran et al. All rights reserved. Wed, 22 May 2013 09:43:39 +0000 http://www.hindawi.com/journals/amse/2013/574738/ Titanium dioxide thin films were deposited on crystalline silicon substrates by electron beam physical vapor deposition. The deposition was performed under vacuum ranging from 10−5 to 10−6 Torr without process gases, resulting in homogeneous layers with a thickness of around 100 nm. Samples were then annealed at high temperatures ranging from C to C for 4 hours under nitrogen, and their structural and optical properties along with their chemical structure were characterized before and after annealing. The chemical and structural characterization revealed a substoichiometric film with oxygen vacancies, voids, and an interface oxide layer. It was found from X-ray diffraction that the deposited films were amorphous and crystallization to anatase phase occurred for annealed samples and was more pronounced for annealing temperatures above C. The refractive index obtained through spectroscopic ellipsometry ranged between 2.09 and 2.37 in the wavelength range, 900 nm to 400 nm for the as-deposited sample, and jumped to the range between 2.23 and 2.65 for samples annealed at C. The minimum surface reflectance changed from around 0.6% for the as-deposited samples to 2.5% for the samples annealed at C. Yaser M. Abdulraheem, Sahar Ghoraishi, Lidia Arockia-Thai, Suji K. Zachariah, and Moustafa Ghannam Copyright © 2013 Yaser M. Abdulraheem et al. All rights reserved. Wed, 22 May 2013 08:01:34 +0000 http://www.hindawi.com/journals/amse/2013/251472/ Cold-work tool steel is considered to be a nonweldable metal due to its high percentage content of carbon and alloy elements. The application of a new process of the semisolid joining of two dissimilar metals is proposed. AISI D2 cold-work tool steel was thixojoined to 304 stainless steel by using a partial remelting method. After thixojoining, microstructural examination including metallographic analysis, energy dispersive spectroscopy (EDS), and Vickers hardness tests was performed. From the results, metallographic analyses along the joint interface between semisolid AISI D2 and stainless steel showed a smooth transition from one to another and neither oxides nor microcracking was observed. Hardness values obtained from the points in the diffusion zone were much higher than those in the 304 stainless steel but lower than those in the AISI D2 tool steel. The study revealed that a new type of nonequilibrium diffusion interfacial structure was constructed at the interface of the two different types of steel. The current work successfully confirmed that avoidance of a dendritic microstructure in the semisolid joined zone and high bonding quality components can be achieved without the need for force or complex equipment when compared to conventional welding processes. M. N. Mohammed, M. Z. Omar, M. S. Salleh, and K. S. Alhawari Copyright © 2013 M. N. Mohammed et al. All rights reserved. Mon, 20 May 2013 16:18:51 +0000 http://www.hindawi.com/journals/amse/2013/486253/ The development of a lightweight composite (LC) based on Portland cement concrete with waste lightweight aggregate (WLA) additive was carried out to improve the sustainability and environmental impact and to offer potential cost savings without sacrificing strength. Treatment of the surface of the LC exposed to environmental attack by coating with biopolymer based on waste cooking oil doped with titanium dioxide photocatalysis (TOP) with superhydrophilic property was found to affect the mechanical properties of the LC in a systematic way. The results of compressive strength showed that the composite achieved the minimum required strength for lightweight construction materials of 17.2 MPa. Scratch resistance measurements showed that the highest percentages loading of superhydrophilic particles (up to 2.5% of biomonomer weight) for LC's surface coating gave the highest scratch resistance while the uncoated sample showed the least resistances. Scanning electron microscope (SEM) pictures revealed the difference between the surface roughness for LC with and without TOP coating. TOP is also formulated to provide self-cleaning LC surfaces based on two principal ways: (1) the development by coating the LC with a photocatalytic superhydrophilic, (2) if such a superhydrophilic is illuminated by light, the grease, dirt, and organic contaminants will be decomposed and can easily be swept away by rain. Anika Zafiah M. Rus, S. R. Mohid, S. Nurulsaidatulsyida, and N. Marsi Copyright © 2013 Anika Zafiah M. Rus et al. All rights reserved. Sun, 19 May 2013 11:27:06 +0000 http://www.hindawi.com/journals/amse/2013/124365/ Polyaniline (PAN) was prepared by using a technique of chemical synthesis to obtain the insulating emeraldine base form. And then PAN was doped with toluenesulfonic acid (TSA), HCl, or camphor sulfonic acid (CSA) to protonate it into conducting salt form. The morphologies and electrical property of PAN under atmospheric pressure were investigated. Subsequently, the high pressure using a Bridgman anvil cell was applied on the doped PAN, and the effect of high pressure on the properties of doped PAN was analyzed. At normal pressure, the conductivity of PAN increases as the PH value increases. While at high pressures, the conductivity of PAN increases, and then it becomes independent of pressure. The results indicate that the conductivity of PAN is related to the presence of the polaron band, and the doped PAN under high pressure will be enhanced strongly in conductivity because of overlap of polaron band and band. However, with the further increase of the applied pressure, scattering mechanisms of carriers limit the conductivity of PAN. Daihui Huang, Dong Xie, Jingjing Gao, Wangchun Lv, and Shiming Hong Copyright © 2013 Daihui Huang et al. All rights reserved. Thu, 16 May 2013 11:29:39 +0000 http://www.hindawi.com/journals/amse/2013/508179/ Recently, recycled thermoplastic polymers become an alternative resource for manufacturing industrial products. However, they have low mechanical properties compared to the thermosets. In this paper, an attempt has been made to enhance the mechanical properties of recycled high density polyethylene (HDPE) with chopped strand mat (CSM) glass fibres as a synthetic reinforcement and with short oil palm fibres as a biodegradable (natural) reinforcement. The effects of volume fraction of both synthetic and natural fibres on tensile, compression, hardness, and flexural properties of the HDPE were investigated. The failure mechanism of the composite was studied with the aid of optical microscopy. Tensile properties of the HDPE composites are greatly affected by the weight fraction of both the synthetic and the natural fibres. The higher strength of the composites was exhibited when at higher weight fraction of both natural and syntactic fibres which was about 50 MPa. Date palm fibre showed good interfacial adhesion to the HDPE despite the untreated condition used. On the other hand, treatment of the fibres is recommended for higher tensile performance of the composites. B. Aldousiri, M. Alajmi, and A. Shalwan Copyright © 2013 B. Aldousiri et al. All rights reserved. Tue, 14 May 2013 18:06:23 +0000 http://www.hindawi.com/journals/amse/2013/564346/ The work on cellulose fiber composites is typically strictly divided into two separated research fields depending on the fiber origin, that is, from wood and from annual plants, representing the two different industries of forest and agriculture, respectively. The present paper evaluates in parallel wood fibers and plant fibers to highlight their similarities and differences regarding their use as reinforcement in composites and to enable mutual transfer of knowledge and technology between the two research fields. The paper gives an introduction to the morphology, chemistry, and ultrastructure of the fibers, the modeling of the mechanical properties of the fibers, the fiber preforms available for manufacturing of composites, the typical mechanical properties of the composites, the modeling of the mechanical properties with focus on composites having a random fiber orientation and a non-negligible porosity content, and finally, the moisture sensitivity of the composites. The performance of wood and plant fiber composites is compared to the synthetic glass and carbon fibers conventionally used for composites, and advantages and disadvantages of the different fibers are discussed. Bo Madsen and E. Kristofer Gamstedt Copyright © 2013 Bo Madsen and E. Kristofer Gamstedt. All rights reserved. Mon, 13 May 2013 16:54:13 +0000 http://www.hindawi.com/journals/amse/2013/409572/ Nonwoven mats of poly(lactic acid) (PLA), poly(ethylene oxide) (PEO), and poly(ε-caprolactone) (PCL) were prepared at a nano- and submicron scale by solution blow spinning (SBS) and electrospinning in order to compare crystalline structure and morphology developed by both processes during fiber formation. Polymer solutions were characterized by rheometry and tensiometry. Spun fibers were characterized by several analytical steps. SEM analyses showed that both solution blow spun and electrospun fibers had similar morphology. Absence of residual solvents and characteristic infrared bands in the solution blow spun fibers for PLA, PCL, and PEO was confirmed by FTIR studies. XRD diffraction patterns for solution blow spun and electrospun mats revealed some differences related to distinct mechanisms of fiber formation developed by each process. Significant differences in thermal behavior by DSC were observed between cast films of PLA, PCL, and PEO and their corresponding spun nanofibers. Furthermore, the average contact angles for spun PLA and PCL were higher than for electrospun mats, whereas it was slightly lower for PEO. When comparing electrospun and solution blow spun fibers, it was possible to verify that fiber morphology and physical properties depended both on the spinning technique and type of polymer. Juliano E. Oliveira, Luiz H. C. Mattoso, William J. Orts, and Eliton S. Medeiros Copyright © 2013 Juliano E. Oliveira et al. All rights reserved. Mon, 13 May 2013 11:20:58 +0000 http://www.hindawi.com/journals/amse/2013/392450/ The effect of nanosilica contents on mechanical properties of the epoxy matrix with some nanoparticle aggregations was studied in macroscopic experiments and nanoscale simulation, particularly with regard to the effective modulus and ultimate stress. Three analytical models were used to obtain the effective elastic modulus of nanoparticle-reinforced composites. Based on Monte-Carlo method, the special program for the automatic generation of 2D random distribution particles without overlapping was developed for nanocomposite modeling. Weight fractions of nanoparticles were converted to volume fractions, in order to coordinate the content unit in the simulation. In numerical analysis, the weak interface strengthening and toughening mechanism was adopted. Virtual crack closure technique (VCCT) and extended finite element method (XFEM) were used to simulate phenomena of nanoparticle debonding and matrix crack growth. Experimental and simulation results show a good agreement with each other. By way of simulation, the weak interface toughening and strengthening mechanism of nanocomposites is confirmed. Zhenqing Wang, Fang Liu, Wenyan Liang, and Limin Zhou Copyright © 2013 Zhenqing Wang et al. All rights reserved. Tue, 23 Apr 2013 09:59:11 +0000 http://www.hindawi.com/journals/amse/2013/648943/ In order to reduce on-site building time, the construction industry shows an increasing interest in stay-in-place formwork with a reinforcement function after concrete hardening, such as CFRP formwork confinement for columns. The current combined systems however do not answer the demand of the building industry for a material system that is both lightweight and fire safe. High performance textile reinforced cement (TRC) composites can address this need. They can be particularly interesting for the shear reinforcement of concrete beams. This paper describes a preliminary analysis and feasibility study on structural stay-in-place formwork made of TRC. Comparative bending experiments demonstrate that a fully steel reinforced beam and an equivalent beam with shear reinforcement in TRC formwork show similar yielding behaviour, indicating that the TRC shear reinforcement system actually works. Moreover, the cracking moment of the concrete was more or less doubled, resulting in a much lower deflection in serviceability limit state than calculated. Digital image correlation measurements show that the latter is due to the crack bridging capacity of the external TRC shear reinforcement. S. Verbruggen, O. Remy, J. Wastiels, and T. Tysmans Copyright © 2013 S. Verbruggen et al. All rights reserved. Wed, 17 Apr 2013 18:01:27 +0000 http://www.hindawi.com/journals/amse/2013/903236/ This paper presents the reinforcing effects of the inclusion of short polypropylene fibers on recycled foamed asphalt (RFA) mixture. Short polypropylene fibers of 10 mm length with a 0.15% by weight mixing ratio of the fiber to the asphalt binder were used. The Marshall stability test, the indirect tensile strength test, the resilient modulus test, and wheel tracking test of the RFA mixtures were conducted. The test results were compared to find out the reinforcing effects of the inclusion of the fiber and the other mixtures, which included the conventional recycled foamed asphalt (RFA) mixtures; the cement reinforced recycled foamed asphalt (CRFA) mixtures; the semihot recycled foamed asphalt (SRFA) mixtures; and recycled hot-mix asphalt (RHMA) mixtures. It is found that the FRFA mixture shows higher Marshall stability than the RFA and SRFA mixtures, higher indirect tensile strength than the RFA mixture, and higher rut resistance than the RFA, SRFA, and RHMA mixtures as seen from the wheel tracking test. Yongjoo Kim and Tae-Soon Park Copyright © 2013 Yongjoo Kim and Tae-Soon Park. All rights reserved. Tue, 16 Apr 2013 15:56:09 +0000 http://www.hindawi.com/journals/amse/2013/450820/ Silver oxide thin films were deposited on glass substrates at a temperature of 50°C by chemical bath deposition technique under different deposition times using pure AgNO3 precursor and triethanolamine as the complexing agent. The chemical analysis based on EDX technique shows the presence of Ag and O at the appropriate energy levels. The morphological features obtained from SEM showed that the AgxO structures varied as the deposition time changes. The X-ray diffraction showed the peaks of Ag2O and AgO in the structure. The direct band gap and the refractive index increased as the deposition time increased and was in the range of 1.64–1.95 eV and 1.02–2.07, respectively. The values of the band gap and refractive index obtained indicate possible applications in photovoltaic and photothermal systems. A. C. Nwanya, P. E. Ugwuoke, B. A. Ezekoye, R. U. Osuji, and F. I. Ezema Copyright © 2013 A. C. Nwanya et al. All rights reserved. Tue, 16 Apr 2013 14:03:24 +0000 http://www.hindawi.com/journals/amse/2013/926540/ In this work nickelate nanoparticles were synthesized using a simple and fast new route, which makes use of gelatin as an organic precursor in order to evaluate the performance of the synthesis method to obtain materials and the influence of the strontium replacement on the structural parameters of the powders. Samples of Nd2-xSrxNiO4 ( and 0.4) were calcined at 700 and at a heating of /min for 4 hours. X-ray powder diffraction patterns were obtained for all the samples, and the Rietveld Method was applied in order to determine the crystallite size using Scherrer's equation, the lattice parameters, and phase concentration. The results obtained using these techniques confirmed that the main crystal structure consists of the distorted K2NiF4-type tetragonal I4/mmm. In addition, scanning electron microscopy images revealed the formation of nanosized particles. R. M. P. B. Oliveira, P. M. Pimentel, J. H. Araújo, D. M. A. Melo, M. A. F. Melo, and A. E. Martinelli Copyright © 2013 R. M. P. B. Oliveira et al. All rights reserved. Thu, 11 Apr 2013 12:00:19 +0000 http://www.hindawi.com/journals/amse/2013/916069/ In order to study the mechanical characteristics from creep deformation to failure of rock, the tests of uniaxial compression and pushing steel-plate anchored in rock were performed, by using RLJW-2000 servo test synchronizing with Digital Speckle Correlation Method (DSCM). The investigations showed that for a uniaxial compressive specimen, when load arrived at 0.5, displacement clusters orderly formed, which was ahead of the macrocreep strain occurring in a slight jump mode when load arrived at 0.7. When the load level arrived at 0.8, displacement clusters gathered to be a narrow band. After that, the specimen abruptly fractured in a shear mode. In the creep pushing steel-plate test, when pushing force arrived at 25 kN, crack began to occur, the horizontal displacement field as well as shear strain field concentrated continuously along the interface between steel-plate and rock, and a new narrow concentrating band gathered in the upper layer. When pushing force arrived at 27.5 kN, another new narrow shear deformation band formed in the lower layer. Then, the steel-plate was pushed out quickly accompanying strong creep deformation. Yunliang Tan, Yanchun Yin, and Tongbin Zhao Copyright © 2013 Yunliang Tan et al. All rights reserved. Thu, 11 Apr 2013 10:17:10 +0000 http://www.hindawi.com/journals/amse/2013/710143/ Using the displacement potential approach of orthotropic composite materials for the plane stress conditions, an orthotropic panel subjected to a combined loading at its right lateral edge is solved. Effects of fiber orientations and material isotropy on the elastic field of an orthotropic panel subjected to a combined loading are discussed. The analytical elastic solutions at different sections of the panel with fiber orientation ° are compared with those of finite element predictions to ensure the reliability of our present solutions. S. K. Deb Nath Copyright © 2013 S. K. Deb Nath. All rights reserved. Wed, 10 Apr 2013 14:37:51 +0000 http://www.hindawi.com/journals/amse/2013/568479/ A dental crown material, Nickel-Chrome-Molybdenum alloy, is manufactured using precision casting method from a polyurethane foam model in a regular and open-pore form, as a hard tissue implant for orthopedic applications. The samples produced have 10, 20, and 30 (±3) pores per inch of pore densities and 0.0008, 0.0017, and 0.0027 g/mm3 densities, respectively. Samples were implanted in six dogs and observed for a period of two, four, and six months for the histopathological examinations. The dogs were examined radiologically in 15-day intervals and clinically in certain intervals. The implants were taken out with surrounding tissue at the end of these periods. Implants and surrounding tissues were examined histopathologically in terms of biocompatibility. As a result, it is seen that new bone tissue was formed, in pores of the porous implant at the head of the tibia in dogs implanted. Any pathology, inflammation, and reaction in old and new tissues were not observed. It was concluded that a dental alloy (Ni-Cr-Mo alloy) could also be used as a biocompatible hard tissue implant material for orthopedics. Yusuf Er and Emine Unsaldi Copyright © 2013 Yusuf Er and Emine Unsaldi. All rights reserved. Sun, 31 Mar 2013 17:08:35 +0000 http://www.hindawi.com/journals/amse/2013/703610/ SiC/Ti6Al4V coatings were applied on carbon/carbon composites to improve the surface wettability of water. SiC interlayers were preprepared by pack cementation to bond both the carbon/carbon composites and the Ti6Al4V, and then the Ti6Al4V coatings were applied by magnetron sputtering technique. The morphology and crystalline of the SiC/Ti6Al4V coatings were analyzed by scanning electron microscopy, energy dispersive spectroscopy, and X-ray diffraction. The surface wettability of the coatings was tested by video-based contact angle measuring device. The results showed that SiC can serve as an interlayer between the carbon/carbon composites and Ti6Al4V. The SiC/Ti6Al4V coatings covered the carbon/carbon composites uniformly with spherical morphology. The coatings improved the surface wettability of carbon/carbon composites with the contact angle of water decreasing from 85.7 ± 4.1° to 26.5 ± 0.1°. Lei-Lei Zhang, He-Jun Li, Ke-Zhi Li, Yu-Lei Zhang, Jin-Hua Lu, Sheng Cao, Xue-Ni Zhao, and Zi-Bo He Copyright © 2013 Lei-Lei Zhang et al. All rights reserved. Thu, 28 Mar 2013 14:19:28 +0000 http://www.hindawi.com/journals/amse/2013/478421/ For use in fire resistance calculations, the relevant thermal properties of high-performance concrete (HPC) with fly ash were determined through an experimental study. These properties included compressive strength, cubic compressive strength, cleavage strength, flexural strength, and the ultrasonic velocity at various temperatures (20, 100, 200, 300, 400 and 500∘C) for high-performance concrete. The effect of temperature on compressive strength, cubic compressive strength, cleavage strength, flexural strength, and the ultrasonic velocity of the high-performance concrete with fly ash was discussed according to the experimental results. The change of surface characteristics with the temperature was observed. It can serve as a reference for the maintenance, design, and the life prediction of high-performance concrete engineering, such as high-rise building, subjected to elevated temperatures. Huai-Shuai Shang and Ting-Hua Yi Copyright © 2013 Huai-Shuai Shang and Ting-Hua Yi. All rights reserved. Thu, 28 Mar 2013 09:26:43 +0000 http://www.hindawi.com/journals/amse/2013/289698/ This paper aims at understanding how to model the time-dependent behavior of PMMA during a scratch loading at a constant speed and at middle strain levels. A brief experimental study is first presented, consisting of the analysis of microscratches carried out at various scratching velocities and normal loads. The loading conditions have been chosen in such a way that neither (visco)elasticity nor (visco)plasticity of the PMMA may be neglected a priori. The main analyzed parameter is the tip penetration depth measured during the steady state. Then, a finite element model is used to investigate the potential of classical elastic-viscoplastic constitutive models to reproduce these experimental results. It is mainly shown that these models lead to unsatisfying results. More specifically, it is pointed out here that the time-independent Young modulus used in such models is not suitable. To take into account this feature, a viscoelastic-viscoplastic model based on the connection in series of a viscoelastic part with a viscoplastic part is proposed. It is shown that it leads to more acceptable results, which points out the importance of viscoelasticity in the scratch behavior of solid polymers. G. Kermouche, N. Aleksy, and J. M. Bergheau Copyright © 2013 G. Kermouche et al. All rights reserved. Wed, 27 Mar 2013 15:07:07 +0000 http://www.hindawi.com/journals/amse/2013/483651/ Monodisperse polystyrene (PS) spheres with controllable size have been synthesized by a straight forward and simple procedure. The as-synthesized PS spheres have a typical diameter ranging from ~180 nm to ~900 nm, where a reduced sphere size is obtained by increasing the polyvinylpyrrolidone (PVP)/styrene weight ratio. The PS spheres function as sacrificial templates for the fabrication of hollow silica nanospheres (HSNSs) for thermal insulation applications. By modifying the silica coating process, HSNSs with different surface roughness are obtained. All resulting HSNSs show typically a thermal conductivity of about 20 mW/(mK), indicating that the surface phonon scattering is probably not significant in these HSNS samples. Linn Ingunn C. Sandberg, Tao Gao, Bjørn Petter Jelle, and Arild Gustavsen Copyright © 2013 Linn Ingunn C. Sandberg et al. All rights reserved. Tue, 26 Mar 2013 15:04:52 +0000 http://www.hindawi.com/journals/amse/2013/809247/ This research intends to study the cementing potential of pulverized oyster shell, rich in calcium, when mixed with fly ash and soil. Cylindrical compacted soil and cubic lime specimens with different proportions of the shells and fly ash are made to study the strength variance. Soil, which is classified as CL in the USCS system, commercialized pulverized oyster shell, F-type fly ash, and lime are mixed in different weight percentages. Five sample groups are made to study the compressive strength of soil and lime specimens, respectively. The lime cubes are made with 0.45 W/B ratio and the cylindrical soils are compacted under the standard Procter compaction process with 20% moisture content. The results show that increment of shell quantity result to lower strength on both the soil and lime specimens. In a 56-day curing, the compressive strength of the lime cubes containing fly ash increases evidently while those carrying the shell get little progress in strength. The soil specimens containing fly ash gradually gain strength as curing proceeds. It suggests that mixtures of the shell and fly ash do not process any Pozzolanic reaction nor help to raise the unconfined strength of the compacted soil through the curing. Chou-Fu Liang and Hung-Yu Wang Copyright © 2013 Chou-Fu Liang and Hung-Yu Wang. All rights reserved. Sun, 24 Mar 2013 13:14:30 +0000 http://www.hindawi.com/journals/amse/2013/786769/ An approach to incorporate the coupling between the shear compliance and in-plane tension of woven engineering fabrics, in finite-element-based numerical simulations, is described. The method involves the use of multiple input curves that are selectively fed into a hypoelastic constitutive model that has been developed previously for engineering fabrics. The selection process is controlled by the current value of the in-plane strain along the two fibre directions using a simple algorithm. Model parameters are determined from actual experimental data, measured using the Biaxial Bias Extension test. An iterative process involving finite element simulations of the experimental test is used to normalise the test data for use in the code. Finally, the effectiveness of the method is evaluated and shown to provide qualitatively good predictions. F. Abdiwi, P. Harrison, and W. R. Yu Copyright © 2013 F. Abdiwi et al. All rights reserved. Sun, 24 Mar 2013 09:17:00 +0000 http://www.hindawi.com/journals/amse/2013/674306/ In order to explore the possibility of using low-lime fly ashes, the physical and chemical properties which have a direct bearing on their geotechnical and geoenvironmental behaviors have been investigated. In this paper, two types of low-lime fly ashes, originating from India, have been used. A brief account of various methods adopted in characterizing their physical, chemical, and geotechnical properties is presented. The relative importance of each of these properties in enhancing the bulk applicability of fly ashes has been brought out. Arif Ali Baig Moghal Copyright © 2013 Arif Ali Baig Moghal. All rights reserved. Sun, 24 Mar 2013 09:00:53 +0000 http://www.hindawi.com/journals/amse/2013/712953/ This paper presents an experimental study of behaviour of high-strength concrete at high temperature. Reduction of the mechanical properties of concrete was determined starting from the period when the concrete specimens were heated to the maximum temperature and cooled down to ambient temperature and the additional 96 hours after the initial cooling of the specimens. The study includes determination of compressive strength, dynamic and secant modulus of elasticity, and stress-strain curves of concrete specimens when exposed to temperature level up to 600°C. The study results were compared with those obtained from other studies, EN 1994-1-2 and EN 1992-1-2. Tests point to the fact that compressive strength of concrete continues to reduce rapidly 96 hours after cooling of the specimens to ambient temperature; therefore indicating that the mechanical properties of concrete have substantial reduction after being exposed to high temperature. The study of the dynamic and secant modulus of elasticity shows that both of the properties are reduced but remain constant during the period of 96 hours after cooling. The level of postfire reduction of compressive strength of the analyzed concrete is substantial and could significantly affect the postfire load bearing capacity of a structure. Neno Torić, Ivica Boko, and Bernardin Peroš Copyright © 2013 Neno Torić et al. All rights reserved. Thu, 21 Mar 2013 17:01:14 +0000 http://www.hindawi.com/journals/amse/2013/574914/ Al-Mg and CuZn34 alloys were lap joined using friction stir welding while the aluminum alloy sheet was placed on the CuZn34. In addition, the mechanical properties of each sample were characterized using shear tests. Scanning electron microscopy (SEM) and X-ray diffraction analysis were used to probe chemical compositions. An artificial neural network model was developed to simulate the correlation between the Friction Stir Lap Welding (FSLW) parameters and mechanical properties. Subsequently, a sensitivity analysis was performed to investigate the effect of each input parameter on the output in terms of magnitude and direction. Four methods, namely, the “PaD” method, the “Weights” method, the “Profile” method, and the “backward stepwise” method, which can give the relative contribution and/or the contribution profile of the input factors, were compared. The PaD method, giving the most complete results, was found to be the most useful, followed by the Profile method that gave the contribution profile of the input variables. Mohammad Hasan Shojaeefard, Mostafa Akbari, Mojtaba Tahani, and Foad Farhani Copyright © 2013 Mohammad Hasan Shojaeefard et al. All rights reserved. Thu, 14 Mar 2013 14:36:22 +0000 http://www.hindawi.com/journals/amse/2013/123697/ This paper reviews the function and importance of Sn-Ag-Cu solder alloys in electronics industry and the interfacial reaction of Sn-Ag-Cu/Cu solder joint at various solder forms and solder reflow conditions. The Sn-Ag-Cu solder alloys are examined in bulk and in thin film. It then examines the effect of soldering conditions to the formation of intermetallic compounds such as Cu substrate selection, structural phases, morphology evolution, the growth kinetics, temperature and time is also discussed. Sn-Ag-Cu lead-free solder alloys are the most promising candidate for the replacement of Sn-Pb solders in modern microelectronic technology. Sn-Ag-Cu solders could possibly be considered and adapted in miniaturization technologies. Therefore, this paper should be of great interest to a large selection of electronics interconnect materials, reliability, processes, and assembly community. Liu Mei Lee and Ahmad Azmin Mohamad Copyright © 2013 Liu Mei Lee and Ahmad Azmin Mohamad. All rights reserved. Sun, 10 Mar 2013 09:51:15 +0000 http://www.hindawi.com/journals/amse/2013/391957/ This paper presents the experimental results of recycled aggregate concrete (RAC) specimens prepared with five different amounts of recycled coarse aggregate (RCA) (i.e., 0, 25%, 50%, 75%, and 100%) subjected to impact loading based on split Hopkinson pressure bar tests. Strain-rate effects on dynamic compressive strength and critical strain of RAC were studied. Results show that the impact properties of RAC exhibit strong strain-rate dependency and increase approximately linearly with strain-rate. The transition point from low strain-rate sensitivity to high sensitivity decreases with the increase of matrix strength. Yubin Lu, Xing Chen, Xiao Teng, and Shu Zhang Copyright © 2013 Yubin Lu et al. All rights reserved. Thu, 07 Mar 2013 13:44:18 +0000 http://www.hindawi.com/journals/amse/2013/869075/ The adhesives used for applications in marine environments are subject to particular chemical conditions, which are mainly characterised by an elevated chlorine ion content and intermittent wetting/drying cycles, among others. These conditions can limit the use of adhesives due to the degradation processes that they experience. In this work, the chemical degradation of two different polymers, polyurethane and vinylester, was studied in natural seawater under immersion for different periods of time. The diffusion coefficients and concentration profiles of water throughout the thickness of the adhesives were obtained. Microstructural changes in the polymer due to the action of water were observed by SEM, and the chemical degradation of the polymer was monitored with the Fourier transform infrared spectroscopy (FTIR) and differential scanning calorimetry (DSC). The degradation of the mechanical properties of the adhesive was determined by creep tests with Mixed Cantilever Beam (MCB) specimens at different temperatures. After 180 days of immersion of the specimens, it was concluded that the J-integral value (depending on the strain) implies a loss of stiffness of 51% and a decrease in the failure load of 59% for the adhesive tested. Cristina Alia, María V. Biezma, Paz Pinilla, José M. Arenas, and Juan C. Suárez Copyright © 2013 Cristina Alia et al. All rights reserved.